2020 Fox 38- Mtbr.com
Page 1 of 2 12 LastLast
Results 1 to 200 of 256

Thread: 2020 Fox 38

  1. #1
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501

    2020 Fox 38

    Itís just been released! What do you think?



    https://m.youtube.com/watch?v=vbtQaWgYKwY

  2. #2
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Looks like they've shrunk the F36 to 160mm to not compete.

    It's a significant weight gain over the similar travel previous F36 at 2180g.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  3. #3
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by Dougal View Post
    Looks like they've shrunk the F36 to 160mm to not compete.
    They always do that, donít they? They only sell 150 Pikes now I think. When they used to have 160mm as well. Marketeers like to confuse people, itís like calling a product the 2021 version when it has probably been built in 2019, to be released in March 2020!

  4. #4
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501

    2020 Fox 38

    Yari 29 + Push ACS3 (blue coil / 45lb) + Open bath Novypart SPLUG (180ml of oil) + 180mm steerer tube + 203mm disc brake adapter = 2337g




    2021 Fox 38 29" = 2430g

    When air suspensions are getting better, they are also getting heavier! Does it matter? Not to me, thatís why I run a coil fork and shock.

    Source: https://m.pinkbike.com/news/first-ri...aver-2020.html
    Last edited by digev; 04-07-2020 at 07:00 AM.

  5. #5
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by digev View Post
    2021 Fox 38 29" = 2430g
    I think this is an E-bike fork.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  6. #6
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501

    2020 Fox 38

    Quote Originally Posted by Dougal View Post
    I think this is an E-bike fork.
    Maybe you didnít get the memo but overnight the 36 has become an all mountain fork while the 38 is now the go to fork for enduro. E-bikes would probably need a 40 now (according to the ever changing Fox classification)

    32 SC - XC racing
    34 SC - light trail
    34 - trail
    36 - all mountain
    38 - enduro
    40 - DH

    Source: https://www.ridefox.com/filter.php?m=bike&t=forks





    Thatís exactly what I despise with these companies (and MTB marketing in general), they just canít release a product and say itís great because xyz ... they feel the need to confuse people! (Edit: I wrote LIE, it was a bit strong)

  7. #7
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Looks good, vvc should be a lot better than the current dished piston

    Is it weird Iím most excited about the floating axle? How long did it take us to get back here?!
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  8. #8
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501

    2020 Fox 38

    Quote Originally Posted by JohnnyC7 View Post
    Is it weird Iím most excited about the floating axle? How long did it take us to get back here?!
    Me too! Whatever can reduce friction and improve sensibility ... is a move in the right direction.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Sep 2018
    Posts
    321
    They downgraded the 36 to all mountain... looks like i need new fork now...

  10. #10
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Marketing aside they seem to have packed quit a lot of improvements!

    Now letís see what RS has to say about it


  11. #11
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    This is a solid product for large people that charge hard with 170mm fork travel, and 55# E-bikes.

    The catch is that the weight and cost is pretty comparable to a DC Bartlett or maybe a Boxxer. Does the new Fox 38 work better? It certainly has an A2C disadvantage.

    Since I'm a 180# trail rider, i don't feel the need to carry the extra weight around of the new Fox 38. But I look forward to user reviews.

    Sent from my SM-G960U using Tapatalk

  12. #12
    mtbr member
    Reputation:
    Join Date
    Dec 2017
    Posts
    245
    17 kg 2021 enduro bikes incoming, MTB industry is going in the opposite direction of my idea of progress.

  13. #13
    mtbr member
    Reputation: uzurpator's Avatar
    Join Date
    Dec 2005
    Posts
    922
    Quote Originally Posted by digev View Post
    Marketing aside they seem to have packed quit a lot of improvements!

    Now letís see what RS has to say about it

    I want SRAM to go with it and release a new Totem with 39.99mm stanchions.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Jul 2009
    Posts
    1,323
    Sounds like they increased the volume of the lowers to reduce progression and make it more linear. Wonder what that'll do to the coil fork mods like ACS3 and Smashpot, assuming it'll reduce progression even further

  15. #15
    mtbr member
    Reputation:
    Join Date
    May 2018
    Posts
    21
    Quote Originally Posted by Adodero View Post
    Sounds like they increased the volume of the lowers to reduce progression and make it more linear. Wonder what that'll do to the coil fork mods like ACS3 and Smashpot, assuming it'll reduce progression even further
    In fact, they decreased the volume:

    "There have also been some big changes inside the FOX 38ís air spring. Unlike most forks (including the 36) where the spring piston runs down the inside diameter of the fork stanchions, FOX now uses a floating machined air sleeve. This air sleeve is free to move slightly inside the stanchion, so the piston can maintain a smooth path even if the fork is twisting. This results in improved function when experiencing torsional loads like off-camber sections and heavy braking, The addition of a sleeve means the inside diameter is reduced, and the 38 uses the same piston head size as a FOX 34. The narrower sleeve means the fork runs on slightly higher pressures, but the advantage is that the seal diameter is also smaller so the seal friction is less."

    https://enduro-mtb.com/en/new-fox-float-38-2021-review/

  16. #16
    mtbr member
    Reputation:
    Join Date
    Jul 2009
    Posts
    1,323
    Quote Originally Posted by Altavoz View Post
    In fact, they decreased the volume:

    "There have also been some big changes inside the FOX 38ís air spring. Unlike most forks (including the 36) where the spring piston runs down the inside diameter of the fork stanchions, FOX now uses a floating machined air sleeve. This air sleeve is free to move slightly inside the stanchion, so the piston can maintain a smooth path even if the fork is twisting. This results in improved function when experiencing torsional loads like off-camber sections and heavy braking, The addition of a sleeve means the inside diameter is reduced, and the 38 uses the same piston head size as a FOX 34. The narrower sleeve means the fork runs on slightly higher pressures, but the advantage is that the seal diameter is also smaller so the seal friction is less."

    https://enduro-mtb.com/en/new-fox-float-38-2021-review/
    I was referring to the volume of the lowers.

    As the stanchion compresses, the air in the lowers compresses also and creates what amounts to another air spring. The PB "review" (if you can even call it that) mentions that the channels running down the back of the lowers increases volume.

    I'd expect this has a possible detrimental effect to coil conversions, as they would lose the progression provided by the stanchion compressing into the lowers.

  17. #17
    mtbr member
    Reputation: Velodonata's Avatar
    Join Date
    May 2018
    Posts
    964
    Quote Originally Posted by Adodero View Post
    I was referring to the volume of the lowers.

    As the stanchion compresses, the air in the lowers compresses also and creates what amounts to another air spring. The PB "review" (if you can even call it that) mentions that the channels running down the back of the lowers increases volume.

    I'd expect this has a possible detrimental effect to coil conversions, as they would lose the progression provided by the stanchion compressing into the lowers.
    Those little channels can't be that much of an increase, I expect it's primarily higher volume simply because it's bigger overall. The buttons may be handy but most of that sounds like marketing gloss. If oil never got up there before those magic channels then we have all been living a lie for a long time. I am curious how much of an effect the dead space in a typical fork contributes to progression, but I'm not convinced it's that significant since most coil conversions seem to incorporate an anti bottoming element.

  18. #18
    mtbr member
    Reputation:
    Join Date
    Nov 2016
    Posts
    3,108
    Quote Originally Posted by Adodero View Post
    I was referring to the volume of the lowers.

    As the stanchion compresses, the air in the lowers compresses also and creates what amounts to another air spring. The PB "review" (if you can even call it that) mentions that the channels running down the back of the lowers increases volume.

    I'd expect this has a possible detrimental effect to coil conversions, as they would lose the progression provided by the stanchion compressing into the lowers.
    When you switch to a coil conversion it's no longer a closed system.

    Sent from my SM-N975U1 using Tapatalk

  19. #19
    Formerly PaintPeelinPbody
    Reputation: PHeller's Avatar
    Join Date
    Dec 2012
    Posts
    2,713
    Yea I really can't see how a coil conversion would be impacted by anything going on with the revised air system.

    That fact that they are using an air sleeve might indicate they are moving towards what Ohlins is doing with the RXF Air/Coil. That is, you can swap the coil for air and back again without worrying about sealing issues to coils scaring the internal bore.

    Are they employing this air sleeve on the 36 as well?
    Work - Utility GIS Analyst
    Party - 2019 Guerrilla Gravity Revved Trail Pistol Sz 3

  20. #20
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by PHeller View Post
    Are they employing this air sleeve on the 36 as well?
    Nope.


  21. #21
    Formerly PaintPeelinPbody
    Reputation: PHeller's Avatar
    Join Date
    Dec 2012
    Posts
    2,713
    hmmm...

    In any case, the Mezzer (or older versions of Lyrik and 36) takes the cake for its versatility - being able to run 140-170mm on the same fork is still a big selling point for people who don't like buy new stuff every year. It's also lighter than 38. Bravo to Manitou on that note.

    I do think it's cool that the 36 shed some weight, too. Its nearing the Pike and Ribbon in terms of weight. The question will be - does it creak?

    I wouldn't be surprised to see the 34 fazed out (or beefed up) to make room for a 36 Trail that is limited to 140mm travel. Imagine a step-cast 36? Likewise, a stiffer 34 limited to 140mm would be cool too. Definitely some options for that bracket.

    Personally, I'm relieved at the loss of versatility in 36/38 range. I can honestly say I'm not super interested in these forks.

    Apparently MRP and Rockshox have other forks in the works.
    Work - Utility GIS Analyst
    Party - 2019 Guerrilla Gravity Revved Trail Pistol Sz 3

  22. #22
    mtbr member
    Reputation:
    Join Date
    Nov 2014
    Posts
    479
    Quote Originally Posted by JohnnyC7 View Post
    Is it weird Iím most excited about the floating axle? How long did it take us to get back here?!
    If you're running high quality hubs, will this even make a difference? I run I9 hubs and prefer the Kabolt axle, so it seems to me like the new design might not be worth the added complexity and extra steps every time I remove or install the front wheel.

  23. #23
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by dlxah View Post
    If you're running high quality hubs, will this even make a difference? I run I9 hubs and prefer the Kabolt axle, so it seems to me like the new design might not be worth the added complexity and extra steps every time I remove or install the front wheel.
    Probably even more so, because everyone else will have a fairly large tolerance on their axle width, fox likely made their previous design something like .1mm wider (although itís not something I actually measure regularly) to easily fit a wide range of hubs. So am i9 hub would lose out by being made exactly on spec!

    The system doesnít really seem that strenuous. If you regularly remove your front wheel thatís why they make the QR. thatís up to you which is the priority
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  24. #24
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Ok so I may have been out by an order of magnitude or so 
    Last edited by JohnnyC7; 4 Weeks Ago at 05:18 PM.
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  25. #25
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by JohnnyC7 View Post
    Ok so I may have been out by an order of magnitude or so
    Attachment 1322863
    +/- 2mm

    Do I read that right??

  26. #26
    mtbr member
    Reputation:
    Join Date
    Nov 2014
    Posts
    479
    Quote Originally Posted by JohnnyC7 View Post
    Ok so I may have been out by an order of magnitude or so 😂😂
    Attachment 1322863
    Damn, +/- 2mm? That's pathetic. Remind me why these things cost $1000.

  27. #27
    Formerly PaintPeelinPbody
    Reputation: PHeller's Avatar
    Join Date
    Dec 2012
    Posts
    2,713
    Interesting, so the 38 can be reduced to 140mm.
    Work - Utility GIS Analyst
    Party - 2019 Guerrilla Gravity Revved Trail Pistol Sz 3

  28. #28
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by PHeller View Post
    Apparently MRP and Rockshox have other forks in the works.
    What do you know about a new mrp fork?

  29. #29
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by PHeller View Post
    Interesting, so the 38 can be reduced to 140mm.
    Itís the ęUser Specification DrawingĽ for the 36. They did not publish the 38 yet.

    https://www.ridefox.com/fox17/help.p...all=specsheets

    I'd be surprised if you could but who knows.

  30. #30
    mtbr member
    Reputation: RBoardman's Avatar
    Join Date
    Dec 2014
    Posts
    3,100
    Quote Originally Posted by digev View Post
    Marketing aside they seem to have packed quit a lot of improvements!

    Now letís see what RS has to say about it

    Kinda funny he just posted this. Those arenít 35mm sanctions if you ask me. #ZEB





  31. #31
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by RBoardman View Post
    Kinda funny he just posted this. Those arenít 35mm sanctions if you ask me. #ZEB





  32. #32
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501



  33. #33
    mtbr member
    Reputation:
    Join Date
    Apr 2017
    Posts
    241
    Quote Originally Posted by GT87 View Post
    What do you know about a new mrp fork?
    all that I have heard from people is that it will increase travel to 170mm for 29er. (guessing upping to 180 27.5) from the Ribbons current 160 29er and 170 27.5.

    180+ 29er will be handled by the bartlett

  34. #34
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    It wasn't that many years ago the F32 was available in 150mm.

    Now the F36 is limited to 160mm!

    Rockshox, your move.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  35. #35
    mtbr member
    Reputation:
    Join Date
    Nov 2014
    Posts
    479
    Does this mean the new 36 chassis is physically limited to 160mm now, or will it still be compatible with the old 170+mm air spring shafts and aftermarket coil kits?

  36. #36
    mtbr member
    Reputation: RBoardman's Avatar
    Join Date
    Dec 2014
    Posts
    3,100
    Quote Originally Posted by Dougal View Post
    It wasn't that many years ago the F32 was available in 150mm.

    Now the F36 is limited to 160mm!

    Rockshox, your move.
    Fox36 is the new down county fork as seen on this Tallboy.

  37. #37
    mtbr member
    Reputation:
    Join Date
    Dec 2018
    Posts
    333
    Quote Originally Posted by davideb87 View Post
    17 kg 2021 enduro bikes incoming, MTB industry is going in the opposite direction of my idea of progress.
    We are already here!

    My 2020 commencal meta AM29 is 17.6kg, coil suspension front and back and a cushcore in the rear. To be honest there is no disadvantage to me as I'm 90kg anyway. The weight actually tracks better and provides more grip if anything.

  38. #38
    mtbr member
    Reputation: Davide's Avatar
    Join Date
    Jan 2004
    Posts
    3,154
    Quote Originally Posted by digev View Post
    They always do that, donít they? They only sell 150 Pikes now I think. When they used to have 160mm as well. Marketeers like to confuse people, itís like calling a product the 2021 version when it has probably been built in 2019, to be released in March 2020!
    What I find fairly ridiculous (more than the so predictable 38 vs 36 mm saga and related pointless discussions about % increase in rigidity), is that you have to spend $1000 plus to get a sticky air fork that finally Fox admits looses its setting over time because of air build up in the lowers ... and therefore needs to be periodically vented!

    Incredible ... and the commercial megaphones on the Web call it "revamped"!

  39. #39
    mtbr member
    Reputation: Davide's Avatar
    Join Date
    Jan 2004
    Posts
    3,154
    Nice!

  40. #40
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by 2zmtnz View Post
    all that I have heard from people is that it will increase travel to 170mm for 29er. (guessing upping to 180 27.5) from the Ribbons current 160 29er and 170 27.5.

    180+ 29er will be handled by the bartlett
    Still waiting for the short offset Bartlett. Shouldn't have been hard to make a second set of crowns. Seems like that's the main reason that the Bartlet has been so unpopular. And the lack of coil option. It makes no sense to me that they went to the trouble of making that fork, but then apparently put no effort into offering it with the options that people would want, or getting it into the hands of reviewers.

  41. #41
    mtbr member
    Reputation:
    Join Date
    Dec 2018
    Posts
    34
    Has anyone looked at the way VVC works?

    What is the difference between preloading a shim stack with a leaf spring vs a coil spring? Does the leaf spring have a different damping curve to a coil spring?

  42. #42
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by sean44 View Post
    Has anyone looked at the way VVC works?
    Posted 1h ago

    https://m.youtube.com/watch?v=krLP9cawQAA

    Plenty of info about the VVC here as well: https://m.pinkbike.com/u/mikelevy/bl...p2-damper.html

  43. #43
    mtbr member
    Reputation:
    Join Date
    Nov 2014
    Posts
    479
    Quote Originally Posted by sean44 View Post
    Has anyone looked at the way VVC works?

    What is the difference between preloading a shim stack with a leaf spring vs a coil spring? Does the leaf spring have a different damping curve to a coil spring?
    With VVC, they're actually changing the effective length of the leaf spring at the turn of the knob. That means they can essentially change the spring rate of the value as opposed to just the preload.

  44. #44
    mtbr member
    Reputation: rynomx785's Avatar
    Join Date
    Jul 2018
    Posts
    1,041
    Quote Originally Posted by digev View Post
    Very cool. I really want to try a 38.

  45. #45
    mtbr member
    Reputation:
    Join Date
    Mar 2007
    Posts
    119
    The added weight of the 38 makes this a no go for me. Get an 36 & coil conversion will be a better performer. Limiting the 36 to 160 is a crap move. Wonder if the new 36 can go to 170 still with coil conversion or new airspring?

  46. #46
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by wingsno19 View Post
    Wonder if the new 36 can go to 170 still with coil conversion or new airspring?
    We'll find out soon enough but I'm optimistic.

  47. #47
    mtbr member
    Reputation: rynomx785's Avatar
    Join Date
    Jul 2018
    Posts
    1,041
    Quote Originally Posted by wingsno19 View Post
    The added weight of the 38 makes this a no go for me. Get an 36 & coil conversion will be a better performer. Limiting the 36 to 160 is a crap move. Wonder if the new 36 can go to 170 still with coil conversion or new airspring?
    Assuming it uses the same damper as the 38? Really depends on how long they make the stanchions on the 36 I guess. If they are long enough to run 170/180 than you should be able to order the ACS3 kit in a 170/180 seeing as it replaces everything on the spring side anyway.

  48. #48
    mtbr member
    Reputation:
    Join Date
    Nov 2009
    Posts
    2,994
    Quote Originally Posted by digev View Post
    We'll find out soon enough but I'm optimistic.
    Might be in 650b but I would think not on the 29er.
    Last edited by Rick Draper; 04-09-2020 at 12:20 PM.

  49. #49
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by dlxah View Post
    With VVC, they're actually changing the effective length of the leaf spring at the turn of the knob. That means they can essentially change the spring rate of the value as opposed to just the preload.
    Ohlins have been using it on the TTX forks and shocks for a long time now.

    There are three basic ways to increase HSC by adjuster.

    1. Add a preload spring. Rockshox Charger RCT3 and RC2 do this, along with Fox's FIT4-RC2 and the Manitou Mezzer.

    2. Preload the compression shims. Manitou MC^2 (Mattoc Pro), Fox Grip and GRIP2 use this.

    3. Change the flex mode or flex length of the compression shims. Ohlins did this in their TTX, Fox GRIP2 used it for HSR and now fox in their VVC.

    They all have their own upsides and downsides. #3 is different to the others that it doesn't add preload (opening force) to a shim-stack. But it can still be used with a pre-loaded shim stack.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  50. #50
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by wingsno19 View Post
    The added weight of the 38 makes this a no go for me. Get an 36 & coil conversion will be a better performer. Limiting the 36 to 160 is a crap move. Wonder if the new 36 can go to 170 still with coil conversion or new airspring?
    Weight has such a small effect apart from the number on the scales, that shouldn't matter. Especially if you are wanting 180mm of travel a few hundred grams is hardly a trade off
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  51. #51
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by JohnnyC7 View Post
    Weight has such a small effect apart from the number on the scales, that shouldn't matter. Especially if you are wanting 180mm of travel a few hundred grams is hardly a trade off
    The problem is: You could buy the previous F36 at 180mm for significantly less weight. But no longer because Fox have heavily restricted that model now. Pushing 180mm riders into a much heavier fork now.

    You can also get 180mm forks from other brands that are 400g lighter than this F38!

    It's like Fox have just left the 180mm acoustic bike market.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  52. #52
    mtbr member
    Reputation: targnik's Avatar
    Join Date
    Jan 2014
    Posts
    5,262
    My Lyrik, Pike & Yari feel slightly inadequate

    Sent from my HD1900 using Tapatalk
    "Mountain biking: the under-rated and drug-free antidepressant"

  53. #53
    mtbr member
    Reputation:
    Join Date
    Nov 2016
    Posts
    3,108
    Quote Originally Posted by Dougal View Post
    The problem is: You could buy the previous F36 at 180mm for significantly less weight. But no longer because Fox have heavily restricted that model now. Pushing 180mm riders into a much heavier fork now.

    You can also get 180mm forks from other brands that are 400g lighter than this F38!

    It's like Fox have just left the 180mm acoustic bike market.
    Or it's like the whole weight weenie craze all over again. Fox decided that the longevity of the 36, at its weight, wasn't up to snuff, creaky CSUs, and added weight to design a more durable product. Time will tell.

    Sent from my SM-N975U1 using Tapatalk

  54. #54
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Exactly. With modern riding styles, slack head angles, and well 15mm axles, Fox has determined that a 36mm single crown @ 170mm has too much flex and inevitably is going to creak and perform suboptimally when utilized as intended. There might be a small handful of very lightweight senders that don't experience this. Fortunately for them there are an unlimited supply of lightly used 170mm 36mm forks that can be used as is or modified for optimum performance.

    The real question is: why would anyone run a 2400 g 170mm travel 38mm SC fork, when in the same A2C with more rigidity you can run a 35mm 180mm 2400g DC fork? Is it fashion?

    Sent from my SM-G960U using Tapatalk

  55. #55
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by Suns_PSD View Post
    Exactly. With modern riding styles, slack head angles, and well 15mm axles, Fox has determined that a 36mm single crown @ 170mm has too much flex and inevitably is going to creak and perform suboptimally. There might be a small handful of very lightweight senders that don't experience this. Fortunately for them there are an unlimited supply of lightly used 170mm 36mm forks that can be used as is or modified for optimum performance.

    The real question is: why would anyone run a 2400 g 170mm travel fork 38mm SC fork, when in the same A2C with more rigidity you can run a 35mm 180mm 2400g DC?

    Sent from my SM-G960U using Tapatalk
    Fox 36's (and 34's and 32's) creaking is nothing to do with the fork stiffness. It's because they have such a light press-fit. They even greased some forks to stop them creaking. Which it did until the fork was ridden enough to squeeze the grease out.

    The problem Fox have got is making a press-fit tighter would make the install forces too high for their thin stanchion ends (where the groove is for the retaining clip is very thin).

    Ultimately it's Fox's own unique problem. There are several ways around it but they would all slow down fork production.

    I think Fox have just handed a lot of sales to Manitou and whatever Rockshox comes out with.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  56. #56
    mtbr member
    Reputation:
    Join Date
    Feb 2004
    Posts
    83
    Quote Originally Posted by Velodonata View Post
    Those little channels can't be that much of an increase, I expect it's primarily higher volume simply because it's bigger overall. The buttons may be handy but most of that sounds like marketing gloss. If oil never got up there before those magic channels then we have all been living a lie for a long time. I am curious how much of an effect the dead space in a typical fork contributes to progression, but I'm not convinced it's that significant since most coil conversions seem to incorporate an anti bottoming element.
    I believe the lower bushings can trap air when the fork is being compressed hard/quickly. While the channels don't look big, it was explained to me as opening up a larger passage for air (and oil) to make the lower leg volume above the lower bushing much more "available" during these bigger hit moments.

  57. #57
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by Slap Happy View Post
    I believe the lower bushings can trap air when the fork is being compressed hard/quickly. While the channels don't look big, it was explained to me as opening up a larger passage for air (and oil) to make the lower leg volume above the lower bushing much more "available" during these bigger hit moments.
    There's a real challenge with channels like that. It's keeping the leg and bushings in place and round. Because instead of 360 degree support. You've now got a section with no support.

    This might be why the fork is so heavy. They likely had to put a lot more metal in the lowers to hold shape.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  58. #58
    mtbr member
    Reputation: bajaguy's Avatar
    Join Date
    Jul 2009
    Posts
    258
    Do the lower legs affect travel adjust or is it just the stanchions and damper? If you wanted to run a Fox 36 at 170 couldn't you just purchase the new lowers with bleed ports and still run a 36 with 170mm of travel? You would just not be able to run the newer 2021 Grip2 damper since those are probably maxed out at 160.

  59. #59
    mtbr member
    Reputation:
    Join Date
    Jan 2018
    Posts
    136
    I'm happy because now adding 400g with smashpot on my 2018 lyrik doesn't bother me as much!! I'll just wait to see if that new badass sexy Rock Shox has a coil version otherwise I'll just go with Vorsprung!

  60. #60
    mtbr member
    Reputation:
    Join Date
    May 2017
    Posts
    739
    Seems the price has gone up accordingly (from https://enduro-mtb.com/en/new-fox-float-38-2021-review/)

    EUR Ä1259 Ė Ä1589
    US $1370 - $1600
    AUS $2200 - $2770
    NZD $2275 - $2900

  61. #61
    mtbr member
    Reputation:
    Join Date
    Dec 2017
    Posts
    245
    Quote Originally Posted by JohnnyC7 View Post
    Weight has such a small effect apart from the number on the scales, that shouldn't matter. Especially if you are wanting 180mm of travel a few hundred grams is hardly a trade off
    I read statements like yours many times, every year. The result is enduro bikes average weight is now around 15/15.5 kg. With these freeride forks we are now adding 350-400 g more.
    It's not a few hundred grams, it's about 3 kg and more over 5 years old enduro bikes.
    They don't have a small effect, not for me at least.

    I think every fork producer can simply add 400g of material and make a rigid fork, progress is a different thing for me.
    The 36 chassis wasn't the most rigid, competitors proved it at the same weight range, i think they had to work on that instead.

  62. #62
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by springs View Post
    Seems the price has gone up accordingly (from https://enduro-mtb.com/en/new-fox-float-38-2021-review/)

    EUR Ä1259 Ė Ä1589
    US $1370 - $1600
    AUS $2200 - $2770
    NZD $2275 - $2900
    Wow.

    Down this way we will be getting close to $4k with a Smashpot, burnishing,service and whatever else they need.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  63. #63
    mtbr member
    Reputation:
    Join Date
    Apr 2009
    Posts
    987
    Quote Originally Posted by Dougal View Post
    Wow.

    Down this way we will be getting close to $4k with a Smashpot, burnishing,service and whatever else they need.
    Can pick a mezzer up for £690

  64. #64
    mtbr member
    Reputation:
    Join Date
    Apr 2018
    Posts
    1,498
    @DOUGAL, this HSR system seems gimmicky does it not? sounds like he's saying preload is bad, but we are also using preload by changing the leverage on the wing. "it feels like you have a lighter stack"

    What am i missing here? seems marketing-driven rather than damping-quality driven, if that makes sense.


    https://youtu.be/krLP9cawQAA?t=308

  65. #65
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    The VVC doesnít have any preload, it is essentially a leaf spring or lever that you are changing the length of. By adding hsr you are trying to bend it from a point closer to the pivot do itís harder to flex
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  66. #66
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by davideb87 View Post
    I read statements like yours many times, every year. The result is enduro bikes average weight is now around 15/15.5 kg. With these freeride forks we are now adding 350-400 g more.
    It's not a few hundred grams, it's about 3 kg and more over 5 years old enduro bikes.
    They don't have a small effect, not for me at least.

    I think every fork producer can simply add 400g of material and make a rigid fork, progress is a different thing for me.
    The 36 chassis wasn't the most rigid, competitors proved it at the same weight range, i think they had to work on that instead.
    But are modern enduro bikes not infinitely better than 5 years ago? And itís not as though there is no way to build a light bike any more.

    BTW fox did just confirm the 36 will still be able to run @ 170mm

    I weighed my bike for the first time the other week. 16 kg 😂😂😂
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  67. #67
    Elitest thrill junkie
    Reputation: Jayem's Avatar
    Join Date
    Jul 2005
    Posts
    34,134
    Quote Originally Posted by JohnnyC7 View Post
    But are modern enduro bikes not infinitely better than 5 years ago? And itís not as though there is no way to build a light bike any more.
    I think no, I think that we are reaching more of a plateau at this point.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  68. #68
    Formerly PaintPeelinPbody
    Reputation: PHeller's Avatar
    Join Date
    Dec 2012
    Posts
    2,713
    I think what we're finding is that Enduro is becoming enough of a marketing segment that we're now getting focused products specifically for that event type. Just as we've got the 32SC and 34SC for XC/Marathon and the 40 for Downhill, the 38 is an unabashed enduro product, meant for people who don't want or need any versatility in their race bike.

    The 36 isn't dead and has its place in the lineup, Fox told us that by giving the 36 many of these same upgrades (minus the floating air spring shaft). The 36 is still the most versatile fork in the lineup, especially now that it's 1950ish grams.

    Just as now most people can run their local enduro events and probably place just fine on a Pike, Lyrik, 36 or 34, I'm sure the vast majority of riders won't notice any improvements in their riding based on the 38. Will they want it? Sure. Just as people want lifted trucks, fast cars and mostly empty homes. It's all about signalling, and the 38 signals "I'm a real rider bro!"
    Work - Utility GIS Analyst
    Party - 2019 Guerrilla Gravity Revved Trail Pistol Sz 3

  69. #69
    mtbr member
    Reputation: kwapik's Avatar
    Join Date
    Feb 2016
    Posts
    542
    Quote Originally Posted by springs View Post
    Seems the price has gone up accordingly (from https://enduro-mtb.com/en/new-fox-float-38-2021-review/)

    EUR Ä1259 Ė Ä1589
    US $1370 - $1600
    AUS $2200 - $2770
    NZD $2275 - $2900
    The US prices are totally incorrect - maybe they forgot to remove the VAT?

    The Fox 38 retails for:
    ó $949 for the Performance series fork
    ó $1109 for the Performance Elite
    ó $1199 for the Factory

    The 2020 Fox 36 Factory retailed for $1079

  70. #70
    mtbr member
    Reputation:
    Join Date
    Apr 2018
    Posts
    1,498
    Quote Originally Posted by JohnnyC7 View Post
    The VVC doesnít have any preload, it is essentially a leaf spring or lever that you are changing the length of. By adding hsr you are trying to bend it from a point closer to the pivot do itís harder to flex
    aka preload.

  71. #71
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by FactoryMatt View Post
    aka preload.
    No.....preload means there is a force being applied by the valve in its static state. The rate of the spring doesnít change but the force to open it does. With vvc you are changing the rate of the valve spring while still having technically zero opening force
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  72. #72
    mtbr member
    Reputation:
    Join Date
    Apr 2018
    Posts
    1,498
    trying to learn here, how does reducing the lever on the wing *not* increase force required to open it (in addition to steepening the rate unlike conventional preload that only shifts the rate upward)

  73. #73
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by FactoryMatt View Post
    trying to learn here, how does reducing the lever on the wing *not* increase force required to open it (in addition to steepening the rate unlike conventional preload that only shifts the rate upward)
    Any spring (eg a shim stack, coil spring) in its relaxed state will *technically* compress with any non-zero force on it, it may only be a tiny amount but it will still move. The amount of force it takes to open a particular amount will change with rate though. The same reason why a plain shim stack is usually preferred over one with preload, because a preloaded stack is pushing down on the piston and that force needs to be ovecome before it will open.

    Added a side-on picture of the rebound piston to show how the leaf spring/wing is always in a flat, relaxed state
    2020 Fox 38-2020-04-10_0813.png
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  74. #74
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by FactoryMatt View Post
    @DOUGAL, this HSR system seems gimmicky does it not? sounds like he's saying preload is bad, but we are also using preload by changing the leverage on the wing. "it feels like you have a lighter stack"

    What am i missing here? seems marketing-driven rather than damping-quality driven, if that makes sense.


    https://youtu.be/krLP9cawQAA?t=308
    To clear up some confusion. The HSR system they used in the GRIP2 does indeed use preload.
    That finger (leaf spring) that is providing the additional support to the rebound shim stack is indeed preloaded and that is adjustable internally and needs to be set correctly on assembly.

    The opportunity for a tech who doesn't know what they're doing to screw up that damper is immense.

    As far as HSR being gimmicky. I do agree. The HSR shim stack needs tuned to match your spring rate. It is only very lightly sprung or very heavily sprung riders who need a change in HSR. Those riders are far better catered to with a shim stack change.

    I'm a big fan of simpler hardware and better tuning rather than more complex hardware which tends to compromise core functions and massively increase cost.

    The F38 VVC compression looks to function in the same was as the GRIP2 HSR. So yes. It's also using preload.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  75. #75
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    849
    Quote Originally Posted by FactoryMatt View Post
    aka preload.
    Preload is when the spring is bent in its static position. Neither the leaf spring or shims are bent without damper movement in this "VVC" setup.

  76. #76
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by PhillipJ View Post
    Preload is when the spring is bent in its static position. Neither the leaf spring or shims are bent without damper movement in this "VVC" setup.
    He's right, they are both preloaded. Both HSR and VVC use a preloaded finger and change the fulcrum point underneath it.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  77. #77
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    I pulled a couple of dyno runs to show the difference between the 2 adjuster styles.

    Bottom is a float X2 with the preloaded spring adjustment that shifts the opening point, but doesn't change the rate, so clearly a digressive characteristic. The Top is from a Grip2 36 where the VVC changing the slope of the HSR section of the curve, but they all diverge from a similar point, giving a more linear curve

    2020 Fox 38-2020-04-10_0901.jpg2020 Fox 38-2020-04-10_0938.jpg
    Attached Thumbnails Attached Thumbnails 2020 Fox 38-2020-04-10_0851.jpg  

    Last edited by JohnnyC7; 04-09-2020 at 02:40 PM. Reason: Found a better HSR sweep
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  78. #78
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by PHeller View Post
    I think what we're finding is that Enduro is becoming enough of a marketing segment that we're now getting focused products specifically for that event type. Just as we've got the 32SC and 34SC for XC/Marathon and the 40 for Downhill, the 38 is an unabashed enduro product, meant for people who don't want or need any versatility in their race bike.

    The 36 isn't dead and has its place in the lineup, Fox told us that by giving the 36 many of these same upgrades (minus the floating air spring shaft). The 36 is still the most versatile fork in the lineup, especially now that it's 1950ish grams.

    Just as now most people can run their local enduro events and probably place just fine on a Pike, Lyrik, 36 or 34, I'm sure the vast majority of riders won't notice any improvements in their riding based on the 38. Will they want it? Sure. Just as people want lifted trucks, fast cars and mostly empty homes. It's all about signalling, and the 38 signals "I'm a real rider bro!"
    This is accurate
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  79. #79
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Have Fox said in what configuration the F36 is 1950g?

    I see they make it from non-boost 26" through to boost 29". Is the new one lighter or heavier than the same configuration from yesterday?
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  80. #80
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    849
    Quote Originally Posted by Dougal View Post
    He's right, they are both preloaded. Both HSR and VVC use a preloaded finger and change the fulcrum point underneath it.
    I'll take your word for it because I can't see any more than what's in the Fox videos.

    Dyno plots from Johnny look like what I'd expect from no or very little preload. That is, even though there is preload that isn't the thing (or not the only thing) that's changed when you twiddle the knob, the overall stiffness is changed.

  81. #81
    mtbr member
    Reputation:
    Join Date
    Nov 2014
    Posts
    479
    Quote Originally Posted by Dougal View Post
    Have Fox said in what configuration the F36 is 1950g?

    I see they make it from non-boost 26" through to boost 29". Is the new one lighter or heavier than the same configuration from yesterday?
    Lightest configuration, so probably 27.5 / 150mm / Fit4 / Kabolt. I think that's roughly the same as the previous model.

  82. #82
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by PhillipJ View Post
    I'll take your word for it because I can't see any more than what's in the Fox videos.

    Dyno plots from Johnny look like what I'd expect from no or very little preload. That is, even though there is preload that isn't the thing (or not the only thing) that's changed when you twiddle the knob, the overall stiffness is changed.
    You're adding preload to an existing flat stack. So it's never going to look like an X2 poppet curve and I have no idea why Jono has even posted those.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  83. #83
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    849
    So is it significantly different from using a ring shim and applying force to the shims above it? Seems like a lot of effort to just preload the stack in a different way.

  84. #84
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by PhillipJ View Post
    So is it significantly different from using a ring shim and applying force to the shims above it? Seems like a lot of effort to just preload the stack in a different way.
    It's much softer than ring shim preload. It means all your shims are still starting from zero preload and it's only this one lever pushing down.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  85. #85
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Simply adding preload to a shim stack still offsets the opening point, but the shims control the slope after opening. Regardless, the slope doesnít change across any part of the range. Typically the base stacks are very soft so the results are indistinguishable from a straight poppet with no base stack. Obviously you can revalve the base shims but that defeats the point of discussing adjuster styles. I could post runs from a fox rc2 base valve but they are on compression so arenít an exact comparison either. Funnily enough I donít have any data from an old boxer r2c2

    The point is Grip2 starts with zero preload(assuming proper assembly) and stays that way
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  86. #86
    change is good
    Reputation:
    Join Date
    Sep 2004
    Posts
    2,995
    So what about this fork fork for fatty fat fat fats? I was all over the SuperMax and then the 36 like a fat kid likes cake for my short travel 29ers. Currently 230lb, hopefully 215lb prison camp configuration by end of summer. Chunky SW trails with some single black thrown in.


    Sent from my iPhone using Tapatalk Pro

  87. #87
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Shouldnít be a problem at all. I get riders your size all the time and this (or 36) would be top of my list of suggestions
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  88. #88
    mtbr member
    Reputation: Velodonata's Avatar
    Join Date
    May 2018
    Posts
    964
    Quote Originally Posted by JohnnyC7 View Post
    The point is Grip2 starts with zero preload(assuming proper assembly) and stays that way
    Have you confirmed that it is assembled with zero preload on the wing leaf spring? In the Jordi video it looks like it has some preload but in the tech drawing you posted it is not so clear. It is a clever design, whatever amount of preload there is or isn't will indeed stay consistent throughout the range of adjustment. It could even be adjusted too if there was ever a reason for it, by changing the ramp of the spirals.

  89. #89
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    849
    Quote Originally Posted by Velodonata View Post
    whatever amount of preload there is or isn't will indeed stay consistent throughout the range of adjustment..
    That's why I thought FactoryMatt's "AKA preload" comment was basically incorrect. There might be some preload but it's not what the HSC knob changes.

  90. #90
    Formerly PaintPeelinPbody
    Reputation: PHeller's Avatar
    Join Date
    Dec 2012
    Posts
    2,713
    What impacts does an increase in air pressure for heavier riders have on the stiction of seals, and is that negated by the 38's floating air spring?

    I've always wondered if high pressures make fork seals drag or bind more.

    Fox must not think so, and believes the stresses and flex of a smaller fork have more impact on the sensitivity than the pressures inside the air spring.
    Work - Utility GIS Analyst
    Party - 2019 Guerrilla Gravity Revved Trail Pistol Sz 3

  91. #91
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by PHeller View Post
    What impacts does an increase in air pressure for heavier riders have on the stiction of seals, and is that negated by the 38's floating air spring?

    I've always wondered if high pressures make fork seals drag or bind more.

    Fox must not think so, and believes the stresses and flex of a smaller fork have more impact on the sensitivity than the pressures inside the air spring.
    Yes more pressure = more squeeze=more friction, but foxís answer in the recent Pinkbike AMA was that it it offset but the floating air piston assembly
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  92. #92
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by Velodonata View Post
    Have you confirmed that it is assembled with zero preload on the wing leaf spring? In the Jordi video it looks like it has some preload but in the tech drawing you posted it is not so clear. It is a clever design, whatever amount of preload there is or isn't will indeed stay consistent throughout the range of adjustment. It could even be adjusted too if there was ever a reason for it, by changing the ramp of the spirals.
    It is assembled with preload. Without any it cannot change the opening point of the shims. The leaf is too soft as a spring to make any impact without preload.

    The preload force does change throughout the stroke. But only due to the flex in that finger. Further out (minimum HSC) it has less preload force. Closer in (max HSC) it has more preload force as the finger is shorter and stiffer but has the same forced preload distance.


    Regarding the 170mm air shafts for the F36. I'd be hoping these are more available than the E-bike F36 long travel air shafts. Sure they make them and yes you can get a part number. But apparently they just can't be ordered!
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  93. #93
    battle stag commander
    Reputation: planetx88's Avatar
    Join Date
    Mar 2012
    Posts
    166
    Quote Originally Posted by Dougal View Post
    It is assembled with preload. Without any it cannot change the opening point of the shims. The leaf is too soft as a spring to make any impact without preload.

    The preload force does change throughout the stroke. But only due to the flex in that finger. Further out (minimum HSC) it has less preload force. Closer in (max HSC) it has more preload force as the finger is shorter and stiffer but has the same forced preload distance.

    Regarding the 170mm air shafts for the F36. Sure they make them and yes you can get a part number. But apparently they just can't be ordered!
    My understanding is the shim stack remains unpreloaded regardless of this adjustment. The opening point of the shims do not change, relatively speaking. This adjustment then is essentially an "on-the-fly" tune of the shim stack itself, as if you are physically changing the composition of that stack incrementally, to change the force curve, not the opening point. The way I am thinking about it is you have the basic shim stack, and then in place of preload, you actually have a tuneable shim that can broaden the functional range of that stack. I dont think it covers the whole rider range, but eliminates the need to compromise the function of the stack when you are pinpointing your preferred traits.

    During fox's "ask us anything" on PB yesterday this question about 170mm 36 air shafts. Their answer-"AL: there is a 170mm air spring assembly available for the new 36!" Interestingly, backward compatability of VVC can work for Grip 2. Their answer-"BB: The service parts to do exactly this exist!" You might be right that part numbers for air spring, but new damper parts are not yet available, but they said clearly that VVC will be backward compatible to Grip 2 dampers.

  94. #94
    mtbr member
    Reputation: Velodonata's Avatar
    Join Date
    May 2018
    Posts
    964
    Quote Originally Posted by planetx88 View Post
    My understanding is the shim stack remains unpreloaded regardless of this adjustment. The opening point of the shims do not change, relatively speaking. This adjustment then is essentially an "on-the-fly" tune of the shim stack itself, as if you are physically changing the composition of that stack incrementally, to change the force curve, not the opening point. The way I am thinking about it is you have the basic shim stack, and then in place of preload, you actually have a tuneable shim that can broaden the functional range of that stack. I dont think it covers the whole rider range, but eliminates the need to compromise the function of the stack when you are pinpointing your preferred traits.
    This is the confusing thing about the preload. We have varying accounts of if there actually is any preload, and ambiguous answers even from Fox. From the video of Jordi from Fox, it looks like there is preload, but that is hard to be sure of from a loosely assembled damper being used to make a demo video. From the posted technical drawing, it doesn't have any obvious preload but that doesn't prove anything. My thought is that it probably has some preload designed in just for consistency and it is factored into the tune, and the tuning effect of the device is more similar to changing the shim stack than a simple preloader but probably not a perfect analog. But that is just conjecture at this point. I've spent a lot of money on Fox stuff over the years and I've rarely been impressed but I will give them credit that this seems like a clever design even if it may not be something I ever use. And it seems to have the potential for fine control of its effect by varying both the horizontal and vertical profile of the spiral ramp. Well done Fox, it's been interesting trying to unwind this thing in my head, it's still unlikely you'll see any more of my money for a while.

  95. #95
    mtbr member
    Reputation:
    Join Date
    Sep 2014
    Posts
    116
    It surely has some preload, at least just to make sure it makes contact with the shims all the time without gaps. If there's more, I have no idea.

  96. #96
    battle stag commander
    Reputation: planetx88's Avatar
    Join Date
    Mar 2012
    Posts
    166
    I agree, it is a bit confusing, above you said-

    Quote Originally Posted by Velodonata View Post
    From the video of Jordi from Fox, it looks like there is preload
    Are you refering to the compression/rebound adjustments, or did you see something mentioned about preload itself? I didn't hear him say preload. And you're also right that it's probably not perfectly analagous to changing the shim stack, but I think it is close, which is the point. The idea being, it seems like it doesnt change "when" the valve opens relative to the firmness of the shims stack and force applied, but "how" it opens, at a similar amount of force accross the adjustment of hsc/hsr.

    I reserve the right to be very wrong.

  97. #97
    mtbr member
    Reputation: Velodonata's Avatar
    Join Date
    May 2018
    Posts
    964
    Quote Originally Posted by planetx88 View Post
    ...Are you refering to the compression/rebound adjustments, or did you see something mentioned about preload itself? I didn't hear him say preload. And you're also right that it's probably not perfectly analagous to changing the shim stack, but I think it is close, which is the point. The idea being, it seems like it doesnt change "when" the valve opens relative to the firmness of the shims stack and force applied, but "how" it opens, at a similar amount of force accross the adjustment of hsc/hsr.
    In the video it appeared that there was tension on the finger spring as it was mounted, before he removed it. It looked preloaded to me, inconclusive at best but it still seems like it would require at least a minimal amount of preload to be effective. There were some comments on the video in the PB post that mentioned preload but those were the ambiguity I referred to.

  98. #98
    battle stag commander
    Reputation: planetx88's Avatar
    Join Date
    Mar 2012
    Posts
    166
    gotcha, yea. I agree, gotta stay closed somehow at rest. No externally adjustable preload on shim stack for hsc/hsr it seems though.

  99. #99
    mtbr member
    Reputation:
    Join Date
    Apr 2018
    Posts
    1,498
    just another gimmick that will be discarded for the next generation in favor of another gimmick. sorry not sorry.

  100. #100
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    849
    Quote Originally Posted by FactoryMatt View Post
    just another gimmick that will be discarded for the next generation in favor of another gimmick. sorry not sorry.
    If you reword that to "This is the greatest thing we have ever had. Sorry we can't comment on upcoming product" you'll probably get a job offer from Fox's marketing department.

  101. #101
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by planetx88 View Post
    My understanding is the shim stack remains unpreloaded regardless of this adjustment. The opening point of the shims do not change, relatively speaking. This adjustment then is essentially an "on-the-fly" tune of the shim stack itself, as if you are physically changing the composition of that stack incrementally, to change the force curve, not the opening point. The way I am thinking about it is you have the basic shim stack, and then in place of preload, you actually have a tuneable shim that can broaden the functional range of that stack. I dont think it covers the whole rider range, but eliminates the need to compromise the function of the stack when you are pinpointing your preferred traits.

    During fox's "ask us anything" on PB yesterday this question about 170mm 36 air shafts. Their answer-"AL: there is a 170mm air spring assembly available for the new 36!" Interestingly, backward compatability of VVC can work for Grip 2. Their answer-"BB: The service parts to do exactly this exist!" You might be right that part numbers for air spring, but new damper parts are not yet available, but they said clearly that VVC will be backward compatible to Grip 2 dampers.
    The finger that adds stiffness and preload to the stack is preloaded. It's not a lot but it's there.

    As the finger is rotated the point it adds force to the preloader on the shims varies in a spiral from in close (max stiffness for max HSC) to further out (min stiffness for min HSC).

    There is nothing else going on. It has to be preloaded as without preload it can't add enough force to make a meaningful change to the damping.

    The issue Fox had with the previous Grip2 HSC setup was a limited range and a whole lot of empty clicks which did absolutely nothing.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  102. #102
    mtbr member
    Reputation:
    Join Date
    Sep 2008
    Posts
    48
    there is preload on the shim stack but that preload does not change, the only thing that changes is the amount of force required to move the spring. with the spiral at the end of the spring finger you have more leverage which in turn lets the shim stack open easier and vice versa. jordi explains this pretty clearly in the dialed video.

  103. #103
    Formerly PaintPeelinPbody
    Reputation: PHeller's Avatar
    Join Date
    Dec 2012
    Posts
    2,713
    So what do you think the chances are of a new 66? The old one was also 38mm.

    It would likely need the GRIP damper modified for the 38.

    I see a lot of people happily riding the Marzocchi products, so there is something to be said for the cheaper price point and simplified damper.
    Work - Utility GIS Analyst
    Party - 2019 Guerrilla Gravity Revved Trail Pistol Sz 3

  104. #104
    mtbr member
    Reputation:
    Join Date
    Sep 2016
    Posts
    12
    Does anyone know how/where to purchase the optional bolt-on mud guard?

  105. #105
    battle stag commander
    Reputation: planetx88's Avatar
    Join Date
    Mar 2012
    Posts
    166
    Quote Originally Posted by jason114 View Post
    there is preload on the shim stack but that preload does not change, the only thing that changes is the amount of force required to move the spring. with the spiral at the end of the spring finger you have more leverage which in turn lets the shim stack open easier and vice versa. jordi explains this pretty clearly in the dialed video.
    exactly

  106. #106
    mtbr member
    Reputation: kwapik's Avatar
    Join Date
    Feb 2016
    Posts
    542
    Quote Originally Posted by rygar99 View Post
    Does anyone know how/where to purchase the optional bolt-on mud guard?
    You should be able to order Fox products from your local bike shop or if you prefer - any online retailer who sells Fox. The fender is $25

  107. #107
    mtbr member
    Reputation:
    Join Date
    Sep 2016
    Posts
    12
    Quote Originally Posted by kwapik View Post
    You should be able to order Fox products from your local bike shop or if you prefer - any online retailer who sells Fox. The fender is $25
    I haven't been able to find one listed online anywhere - does anyone know if a particular website is currently selling the FOX made fender online?

  108. #108
    mtbr member
    Reputation: jimarin's Avatar
    Join Date
    Mar 2005
    Posts
    758
    Quote Originally Posted by Altavoz View Post
    In fact, they decreased the volume:

    "There have also been some big changes inside the FOX 38ís air spring. Unlike most forks (including the 36) where the spring piston runs down the inside diameter of the fork stanchions, FOX now uses a floating machined air sleeve. This air sleeve is free to move slightly inside the stanchion, so the piston can maintain a smooth path even if the fork is twisting. This results in improved function when experiencing torsional loads like off-camber sections and heavy braking, The addition of a sleeve means the inside diameter is reduced, and the 38 uses the same piston head size as a FOX 34. The narrower sleeve means the fork runs on slightly higher pressures, but the advantage is that the seal diameter is also smaller so the seal friction is less."

    https://enduro-mtb.com/en/new-fox-float-38-2021-review/
    Is this correct? I know enduro mag said it but it seems pretty odd fox wouldnít mention that at all on the press release.

  109. #109
    mtbr member
    Reputation: Salespunk's Avatar
    Join Date
    Sep 2005
    Posts
    6,068
    Quote Originally Posted by jimarin View Post
    Is this correct? I know enduro mag said it but it seems pretty odd fox wouldnít mention that at all on the press release.
    It is correct and was stated in several articles.

  110. #110
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by jimarin View Post
    Is this correct? I know enduro mag said it but it seems pretty odd fox wouldnít mention that at all on the press release.
    The usual reason for running a spring tube inside is to allow more aggressive internal tapering of the stanchion tube.

    But it's not like the 38 is pushing low weight or anything. So we'll have to wait for a strip-down to see.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  111. #111
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by Dougal View Post
    The usual reason for running a spring tube inside is to allow more aggressive internal tapering of the stanchion tube.

    But it's not like the 38 is pushing low weight or anything. So we'll have to wait for a strip-down to see.
    Fox is claiming that the spring tube is "floating", so they are isolating it from stanchion flex and minimizing piston bind.

  112. #112
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by GT87 View Post
    Fox is claiming that the spring tube is "floating", so they are isolating it from stanchion flex and minimizing piston bind.
    Yes I know what they're claiming. It makes no sense. Why would their biggest single crown fork be suffering stanchion flex?

    How is the 34 and 36 getting on?
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  113. #113
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by Dougal View Post
    Yes I know what they're claiming. It makes no sense. Why would their biggest single crown fork be suffering stanchion flex?

    How is the 34 and 36 getting on?
    Because its being ridden the hardest? Idk. It might be marketing bs, but I could see it making an incremental gain. Any fork will flex some if it's being ridden hard enough. The times when its flexing the most are also the times where you'd most want to minimize friction. If there's any flex at all, it's going to increase friction of the air spring piston.

  114. #114
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by Dougal View Post
    The usual reason for running a spring tube inside is to allow more aggressive internal tapering of the stanchion tube.

    But it's not like the 38 is pushing low weight or anything. So we'll have to wait for a strip-down to see.
    Also, the internal tapering of the stanchion reasoning doesn't make any sense. Could the weight savings of butting the inner stanchions really outweigh the weight gain of a separate spring tube?

  115. #115
    Elitest thrill junkie
    Reputation: Jayem's Avatar
    Join Date
    Jul 2005
    Posts
    34,134
    Quote Originally Posted by Dougal View Post
    Yes I know what they're claiming. It makes no sense. Why would their biggest single crown fork be suffering stanchion flex?

    How is the 34 and 36 getting on?
    Riding progression. E bikes. Extended axle-to-crown of 180mm 29er forks.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  116. #116
    battle stag commander
    Reputation: planetx88's Avatar
    Join Date
    Mar 2012
    Posts
    166
    I think all forks flex, and sometimes more than we think, even with 38 stanchions. However i dont think this is happening in the 38 because of a problem with csu or lower design. I think they are looking at coil products, and suspension products in other applications, and just trying to push the smoothness of air springs as far as possible, by minimizing any drag on air piston. also the difference in friction between a 34 and 38 air spring is something, who knows how big. I think they also had more of a "clean slate" with the 38, and obviously more room to play around with. Maybe a mix of marketing gimmick, applied tech, and "why the f not?"

    also, if the 34 air spring is applicable to the 38, could the 32 be applicable to the 36? Probably a bigger redesign than would be worth it for them right now but maybe some day.

  117. #117
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Everything flexes. The 36 can be visibly flexed by hand, the 38 will also flex just less.

    Sent from my SM-G960U using Tapatalk

  118. #118
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by GT87 View Post
    Also, the internal tapering of the stanchion reasoning doesn't make any sense. Could the weight savings of butting the inner stanchions really outweigh the weight gain of a separate spring tube?
    Butting isnít just about saving weight, it reduces the stress at the point under the crown by spreading the load further down the tube. Weight is just a side effect
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  119. #119
    mtbr member
    Reputation:
    Join Date
    Apr 2018
    Posts
    1,498
    reduction of SKUs. taking a page out of RS's playbook.

    Push & EXT are showing there is a market for premium OTS suspension. Just wait until others get into the fork game.

    i'd rather have a 35mm dual crown than a 38mm single crown anyway. what a joke.

  120. #120
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Quote Originally Posted by FactoryMatt View Post
    i'd rather have a 35mm dual crown than a 38mm single crown anyway. what a joke.
    Yep. I agree with you. I don't need to do bar spins on an e-bike which leaves the 38 in a weird space where it's much heavier with a worse A2C than a 36, but it's also worse in every metric than a hypothetical 35mm DC.

    But how to put together a proper DC 35mm 170-180 travel fork that mounts to a typical headset and has the right offset? What's the parts list or product sku for this?





    Sent from my SM-G960U using Tapatalk

  121. #121
    mtbr member
    Reputation:
    Join Date
    Apr 2018
    Posts
    1,498
    https://mrpbike.com/products/bartlett

    uses the same lower casting as their single crown fork. not sure if the offset is in the triple clamps or the axle lugs, but could be either. takes a conventional stem

  122. #122
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Quote Originally Posted by FactoryMatt View Post
    https://mrpbike.com/products/bartlett

    uses the same lower casting as their single crown fork. not sure if the offset is in the triple clamps or the axle lugs, but could be either. takes a conventional stem
    I'm cool with the conventional stem but the offset is problematic.

    Sent from my SM-G960U using Tapatalk

  123. #123
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by Jayem View Post
    Riding progression. E bikes. Extended axle-to-crown of 180mm 29er forks.
    The A-C of the 180 F38 is little different to the 180mm F36. Also remember that fork flex =/= stanchion flex.

    The vast majority of fork flex is in the crown, brace and axle. The tubes are the most rigid thing.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  124. #124
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by FactoryMatt View Post
    i'd rather have a 35mm dual crown than a 38mm single crown anyway. what a joke.
    Amen

  125. #125
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by Dougal View Post
    The A-C of the 180 F38 is little different to the 180mm F36.
    the 2021 38 forks are each 6.6 millimeters taller than the same-length 36s were last year.
    source: https://www.bikemag.com/gear/compone...ks-unveils-38/

  126. #126
    mtbr member
    Reputation:
    Join Date
    Feb 2019
    Posts
    96
    Quote Originally Posted by Suns_PSD View Post
    I'm cool with the conventional stem but the offset is problematic.

    Sent from my SM-G960U using Tapatalk
    And the narrow lowers. I would say just have a custom tripple clamp made up to reduce the offset but I dont think there'd be much steering angle left if you did that. It looks like there's some offset in the triple clamps, but it think its too much to be able to just flip the triple clamps.

  127. #127
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501

  128. #128
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    What is A2C on the new 36 & 38? Is the 36 the same as years past?

    I dug around quite a bit but was unable to locate.

    Sent from my SM-G960U using Tapatalk

  129. #129
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501

    2020 Fox 38

    Quote Originally Posted by Suns_PSD View Post
    What is A2C on the new 36 & 38? Is the 36 the same as years past?

    I dug around quite a bit but was unable to locate.
    They havenít released any tech doc or drawings yet but hereís the info:

    The axle-to-crown length on the 2021 29-inch 36 is 3.9 millimeters taller than the 2020 version, and the 27.5-inch fork is 4.5 millimeters taller, and we'll learn why in a bit. They max out at a 2.6-inch and 2.8-inch tire respectively. The 38 forks stack on top of that even further. The 29-inch 38 is 2.7mm taller than its 2021 36 counterpart and the 27.5-inch 38 is 2.1mm taller. Add that up, and the 2021 38 forks are each 6.6 millimeters taller than the same-length 36s were last year.
    Source: https://www.bikemag.com/gear/compone...ks-unveils-38/

  130. #130
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    So the old 36 at 160mm was 570mm A2C.
    So the old 36 at 170mm was 580mm A2C.
    So the new 36 at 160mm is 574mm A2C.
    So the new 36 at 170mm is 584mm A2C.
    Then the new 38 at 170 is 587mm A2C.

    For comparison the Bartlett 170mm is 574mm, that's 1/2" shorter than the equivalent travel 38mm fork. The Bartlett at 170mm is the EXACT same A2C as a new 160mm 36 fork!

    DC is the answer for this application where a rider needs a burly 170mm travel trail fork, not the 38.

    I wonder where the Intend DC fork fits in to this equation regarding stiffness/ weight/ and A2C? Maybe it's stiffer than the 36, or even the 38 due it's DC while providing a better A2C than the either of those SC product? We know it falls short of other dual crown forks on the market, but that's not really the comparison since those other DC products don't offer the correct offset, the desired 20mm axle option, nor the lightweight steerer like the Intend does?

  131. #131
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Looking at the Intend Infinity DC fork at 215mm travel it has a 602mm A2C. So with no adjustments to the length of the upper tubes (which would be preferred) if you subtract 30mm of travel you'd have a 185mm travel fork with 572mm A2C. That's less than the A2C of a new 36 at 160mm travel. I have to assume this fork would be more firm than a SC 36?

    * Appears these dimensions above are for a 27.5" fork. Info listed for a 29er not available.

    According to a PB review the Infinity weighed 2510g at 215mm travel, if it was designed to run lower travel this weight could be reduced.

    The Fox 38 in a 170 weighs 2,213 g.

    If Cornelius reduced the max travel this thing could achieve, added some Ti hardware for bling, it's a small weight penalty for the increased travel, improved A2C, and what should be a more rigid platform.

  132. #132
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Also the new Intend Edge (the Single Crown) at 160mm travel has an A2C of only 572mm.

    With the latest round of changes the rigidity of this unit is likely around where a 34-36 fork lies when combined with the knurled 20mm front axle.

    Weight is 2,130 g.

    *edited to reflect 29" in all cases.

  133. #133
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    The previous 36 had a very thin crown at the steerer which reduced the A-C but helped it creak.
    Now it (and the F38) are back in ballpark with other big forks.

    I don't know why you guys are so obsessed with A-C though.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  134. #134
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Because it notably and negatively effects geo.

    Sent from my SM-G960U using Tapatalk

  135. #135
    mtbr member
    Reputation:
    Join Date
    Nov 2016
    Posts
    3,108
    Quote Originally Posted by Suns_PSD View Post
    Because it notably and negatively effects geo.

    Sent from my SM-G960U using Tapatalk
    Or voids the warranty

    Sent from my SM-N975U1 using Tapatalk

  136. #136
    mtbr member
    Reputation:
    Join Date
    May 2017
    Posts
    739
    https://www.youtube.com/watch?v=zxxQPYHjf9A

    Couple of decent hucks to flat showing how much less flex compared to the similar drops on pinkbike with the 36 fork.

  137. #137
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by Suns_PSD View Post
    Because it notably and negatively effects geo.

    Sent from my SM-G960U using Tapatalk
    It doesn't though. You have a geometry target and you set your components around that.

    1/4" fork a-c difference is about 1/4 of a degree. I don't know anyone who can feel that.
    If bar height is your issue that's down to stem and spacer choice.
    If front end height is your issue then stay away from 29" wheels. They're 40mm taller than 27".
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  138. #138
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by FactoryMatt View Post
    https://mrpbike.com/products/bartlett

    uses the same lower casting as their single crown fork. not sure if the offset is in the triple clamps or the axle lugs, but could be either. takes a conventional stem
    The various/ribbons/Ravens/Bartlet all use the same lower castings... the various offsets comes from the crowns. The Bartlett can also take a direct mount stem.

    Quote Originally Posted by Suns_PSD View Post
    Yep. I agree with you. I don't need to do bar spins on an e-bike which leaves the 38 in a weird space where it's much heavier with a worse A2C than a 36, but it's also worse in every metric than a hypothetical 35mm DC.

    But how to put together a proper DC 35mm 170-180 travel fork that mounts to a typical headset and has the right offset? What's the parts list or product sku for this?

    Sent from my SM-G960U using Tapatalk
    It's called a boxxer 29 and it's already available. 35mm, 20mm axle, 46 offset, 582 a2c at 180mm, outweighs the Bartlet by less than 100 grams.

  139. #139
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by Dougal View Post
    It doesn't though. You have a geometry target and you set your components around that.

    1/4" fork a-c difference is about 1/4 of a degree. I don't know anyone who can feel that.
    If bar height is your issue that's down to stem and spacer choice.
    If front end height is your issue then stay away from 29" wheels. They're 40mm taller than 27".
    It's slightly more than that depending on the forks(10mm difference between lyrik and boxxer) which is 0.4 degrees, and I can definitely feel that. I look at it like this... maybe your angles are already as slack as you want them to be, and you don't want to raise your bb either... you can squeeze in an extra 10mm of bonus travel without changing the geo at all.

    If you've already found your "geometry target" you ARE choosing the components based on that... in this case you'd be choosing a fork with extra travel and stiffness.

  140. #140
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    For sure the next set of 170mm Enduro bike frame molds will take in to account the longer A2C of the 38.
    Maybe the 38 is only offered on the L & XL sizes though? Better yet, make it a spec choice.

    Sent from my SM-G960U using Tapatalk

  141. #141
    mtbr member
    Reputation:
    Join Date
    Dec 2008
    Posts
    550
    good gawd, we have gone into a spread sheets tell the truth, hair splitting, sold to by marketing bit of sensitivity. there is not a single person on this thread that can quantify an A-C difference of 5mm or a HA difference of .5 degrees by showing a faster time. if you can, why are you not heavily sponsored by x, y, or z and living the dream? you might as well be saying that "this green is better than that green, i can see the difference, its greener."

    complicate your A-C arguments by the adding the variables in actual difference based off of HA and lower headset stack height, offset, tire diameter, tire pressure, and position in the fork stroke, and you will quickly realize that its a poor carpenter that blames his work on the tools.

  142. #142
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by Suns_PSD View Post
    For sure the next set of 170mm Enduro bike frame molds will take in to account the longer A2C of the 38.
    Maybe the 38 is only offered on the L & XL sizes though? Better yet, make it a spec choice.

    Sent from my SM-G960U using Tapatalk
    Spoiler. They won't. No-one redesigns a bike with 5mm difference in fork length.

    The F38 isn't an outlier for A-C vs travel. The F36 was. The thinner crown was is one of the reasons why so many of them creaked.

    The F38 is the same as Mezzer. Also bikes aren't ridden much at full fork extension.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  143. #143
    mtbr member
    Reputation:
    Join Date
    Nov 2016
    Posts
    3,108
    Quote Originally Posted by Dougal View Post

    The F38 is the same as Mezzer. Also bikes aren't ridden much at full fork extension.
    Which is why the geometry is not calculated to be ridden at full fork extension...

    Sent from my SM-N975U1 using Tapatalk

  144. #144
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by tdc_worm View Post
    good gawd, we have gone into a spread sheets tell the truth, hair splitting, sold to by marketing bit of sensitivity. there is not a single person on this thread that can quantify an A-C difference of 5mm or a HA difference of .5 degrees by showing a faster time. if you can, why are you not heavily sponsored by x, y, or z and living the dream? you might as well be saying that "this green is better than that green, i can see the difference, its greener."

    complicate your A-C arguments by the adding the variables in actual difference based off of HA and lower headset stack height, offset, tire diameter, tire pressure, and position in the fork stroke, and you will quickly realize that its a poor carpenter that blames his work on the tools.
    That's a weird analogy. One shade of green isn't better than another, but I can definitely distinguish between different shades of green, and I might have a preference. Now, if you were to say that the grass is always greener, you might be getting an something...

    I don't think anyone is blaming their tools here. But, a 10mm change in stack height or a half degree in head angle is definitely noticeable to me. It's not even that subtle. I'm not racing, I'm not chasing Strava times... I don't have to justify anything "by showing a faster time".

  145. #145
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by GT87 View Post
    That's a weird analogy. One shade of green isn't better than another, but I can definitely distinguish between different shades of green, and I might have a preference. Now, if you were to say that the grass is always greener, you might be getting an something...

    I don't think anyone is blaming their tools here. But, a 10mm change in stack height or a half degree in head angle is definitely noticeable to me. It's not even that subtle. I'm not racing, I'm not chasing Strava times... I don't have to justify anything "by showing a faster time".
    This is half of your 10mm change though. It's the difference a few psi of tyre pressure makes.

    What is the A-C of a 180mm 29" Lyrik? I can't find it easily.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  146. #146
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    591

  147. #147
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by Dougal View Post
    This is half of your 10mm change though. It's the difference a few psi of tyre pressure makes.

    What is the A-C of a 180mm 29" Lyrik? I can't find it easily.
    What is half of the 10mm change? Boxxer 29 180 is 582, lyrik 29 180 is 592, fox 38 29 180 is 597.

    Whether or not you can alter your geometry by running one of your tires too soft is irrelevant, because it has other consequences and no reasonable person is going to do that. The fact is that they have to overbuild the crown-steerer interface on these long travel SC 29er forks, so if you're discussing the potential merits of a SC vs DC fork, then that is one of the differences worth considering. Maybe that doesn't matter to you. Yes, it's a marginal difference, but all these details are trivial in the grand scheme of things when you're geeking out on bikes like this. Me personally, if I were buying a 180mm 29er fork today, I'd definitely be getting a boxxer over a 38, for several reasons, but you do what suits you.

  148. #148
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by GT87 View Post
    What is half of the 10mm change? Boxxer 29 180 is 582, lyrik 29 180 is 592, fox 38 29 180 is 597.

    Whether or not you can alter your geometry by running one of your tires too soft is irrelevant, because it has other consequences and no reasonable person is going to do that. The fact is that they have to overbuild the crown-steerer interface on these long travel SC 29er forks, so if you're discussing the potential merits of a SC vs DC fork, then that is one of the differences worth considering. Maybe that doesn't matter to you. Yes, it's a marginal difference, but all these details are trivial in the grand scheme of things when you're geeking out on bikes like this. Me personally, if I were buying a 180mm 29er fork today, I'd definitely be getting a boxxer over a 38, for several reasons, but you do what suits you.
    Fox 38 is 597
    Manitou Mezzer is 594
    Fox 36 is 594
    RS Lyrik is 592

    I'm not seeing anything out of the ordinary with these numbers. Nor did I suggest running a tyre soft to compensate.

    I really don't understand what your concern is here. If you want a lower front end, don't run a 29-180 fork! You can drop 20mm from A-C and another 20mm from Ground-Axle by using a 27" front wheel. Boom. 40mm lower.

    Running a 29-180 Boxxer on a frame built for a 29-180 single crown will give you a steeper head angle and lower BB.
    Why would you do that?

    Quote Originally Posted by Suns_PSD View Post
    So the old 36 at 160mm was 570mm A2C.
    So the old 36 at 170mm was 580mm A2C.
    So the new 36 at 160mm is 574mm A2C.
    So the new 36 at 170mm is 584mm A2C.
    Then the new 38 at 170 is 587mm A2C.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  149. #149
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by Dougal View Post
    Fox 38 is 597
    Manitou Mezzer is 594
    Fox 36 is 594
    RS Lyrik is 592

    I'm not seeing anything out of the ordinary with these numbers. Nor did I suggest running a tyre soft to compensate.

    I really don't understand what your concern is here. If you want a lower front end, don't run a 29-180 fork! You can drop 20mm from A-C and another 20mm from Ground-Axle by using a 27" front wheel. Boom. 40mm lower.

    Running a 29-180 Boxxer on a frame built for a 29-180 single crown will give you a steeper head angle and lower BB.
    Why would you do that?
    I don't know why you're so fixated on this axle to crown thing Dougal. Yes, those numbers look normal, for what they are. There is no problem, there is no concern. The lower a2c is one of the MULTIPLE reasons that the boxxer (or Bartlet if you're ok with 51 os) would be a better choice for this application, imo. If my frame were designed for a 180 SC (~593 a2c) then you could run the boxxer at 190 without changing the geo (assuming you don't want to change the geo) giving you 10mm of bonus travel with zero drawbacks... why wouldn't you want that? It's a win-win. The DC is just a more efficient and stronger design. You can run a direct mount stem, shorter cables, have a little bit of geo adjust, replace a single stanchion if one gets damaged. At 180mm of travel I think the main reason people would choose the 38 is for fashion/aesthetics/tradition. Once you're leaning that far toward the gravity end of the spectrum, I couldn't care less about the
    extra couple hundred grams... those compromises are what my 135/160 bike is for.

  150. #150
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Oh yeah, how could I forget.... And no worries about the csu creaking!

  151. #151
    mtbr member
    Reputation:
    Join Date
    Mar 2012
    Posts
    1,195
    I really like the lower leg bleeders. It's such a simple thing to add but critical for consistent performance from one day to the next. Had bleeders on my dirtbike and making sure there was no air build up made a huge difference.

    Still not interested in buying anything from Fox.

  152. #152
    mtbr member
    Reputation:
    Join Date
    Dec 2008
    Posts
    550
    Quote Originally Posted by GT87 View Post
    That's a weird analogy. One shade of green isn't better than another, but I can definitely distinguish between different shades of green, and I might have a preference. Now, if you were to say that the grass is always greener, you might be getting an something...

    I don't think anyone is blaming their tools here. But, a 10mm change in stack height or a half degree in head angle is definitely noticeable to me. It's not even that subtle. I'm not racing, I'm not chasing Strava times... I don't have to justify anything "by showing a faster time".
    the point was that you can't quantify the difference between the two. factor in the bike, the rider, and the trail all being extremely dynamic and independent variables, to get so granular over a-c is a fool's errand. you may like one green more than the other because it makes you feel a certain way, but at the end of the day, its still green, unless it makes you faster.

    we (me included) are all suckers for marketing. all the claims of better, stiffer, lighter, smoother, compliant, yada yada yada do nothing other than making us feel good about pulling our credit card out of our pocket.

    ***I own a Mezzer. I plan to drop it from 180 to 140 (which is super simple and doesnt require a new air shaft) to move to my trail bike. I have a F38 on order that will go on my long travel bike. I don't expect the F38 to be an upgrade. I just want to experiment. If I cannot tune it as easily as the Mezzer, it will be easy to offload and swap back to another Mezzer.

  153. #153
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by tdc_worm View Post
    the point was that you can't quantify the difference between the two. factor in the bike, the rider, and the trail all being extremely dynamic and independent variables, to get so granular over a-c is a fool's errand. you may like one green more than the other because it makes you feel a certain way, but at the end of the day, its still green, unless it makes you faster.

    we (me included) are all suckers for marketing. all the claims of better, stiffer, lighter, smoother, compliant, yada yada yada do nothing other than making us feel good about pulling our credit card out of our pocket.
    I don't need to quantify my 'perfornance gains' in some kinda double blind study dude. If you can't tell the difference, then buy a yari and go rip. If you can't tell the difference between subtle changes like a 0.5 degree of headangle or 10mm of stack, then you definitely won't be able to notice the increased stiffness of the 38 vs the 36, so why are you even here?

    Sure, all of this is a bullshit fools errand, I won't necessarily argue with that. The whole point about the a2c, is that all else being equal, you can 10mm more travel as a bonus because of the more space efficient design and thin lower crown of the DC fork. I really can't see how you can argue that. Of course that alone isnt reason enough to choose one fork over another. If you'd prefer to have kashima than a "better, stiffer smoother" fork, then by all means buy the 38. I really don't care what you do.

  154. #154
    mtbr member
    Reputation:
    Join Date
    Dec 2008
    Posts
    550
    Quote Originally Posted by GT87 View Post
    I don't need to quantify my 'perfornance gains' in some kinda double blind study dude. If you can't tell the difference, then buy a yari and go rip. If you can't tell the difference between subtle changes like a 0.5 degree of headangle or 10mm of stack, then you definitely won't be able to notice the increased stiffness of the 38 vs the 36, so why are you even here?
    if you cannot quantify it, then it isn't a performance gain, it's a preference.
    reach, stack, grips, lever position, bar bends, tires, pedals, saddles...we all have our preferences.

    Quote Originally Posted by GT87 View Post
    Sure, all of this is a bullshit fools errand, I won't necessarily argue with that. The whole point about the a2c, is that all else being equal, you can 10mm more travel as a bonus because of the more space efficient design and thin lower crown of the DC fork. I really can't see how you can argue that. Of course that alone isnt reason enough to choose one fork over another. If you'd prefer to have kashima than a "better, stiffer smoother" fork, then by all means buy the 38. I really don't care what you do.
    apologies....didn't realize that this was a DC vs SC debate...must have overlooked that. on that we can agree. a more efficient packaging will result in a lower A-C, for sure, allowing you to squeeze more travel into a shorter space. since we are geeking out on numbers....any idea what assumptions a frame builder makes when listing their alleged geo's on their we pages? stack height of bottom headset cup? front vs rear tire size/volume? front vs rear sag? geo change vs frame size when weighted? i wonder how wild the actual deviations are from what is listed?

  155. #155
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by tdc_worm View Post
    if you cannot quantify it, then it isn't a performance gain, it's a preference.
    reach, stack, grips, lever position, bar bends, tires, pedals, saddles...we all have our preferences.


    apologies....didn't realize that this was a DC vs SC debate...must have overlooked that. on that we can agree. a more efficient packaging will result in a lower A-C, for sure, allowing you to squeeze more travel into a shorter space. since we are geeking out on numbers....any idea what assumptions a frame builder makes when listing their alleged geo's on their we pages? stack height of bottom headset cup? front vs rear tire size/volume? front vs rear sag? geo change vs frame size when weighted? i wonder how wild the actual deviations are from what is listed?


    The 'performance gain' thing is semamantics. Call it whatever you want. I definitely prefer modern hope v4/e4 disc brakes over old avid v-brakes. I prefer tubeless 2.5" tires over the shitty gumwall 1.8s on my first mtb. I would have even described them as having a performance advantage when riding tech terrain but I'm no scientist so I don't understand the terminology.

    I'm not going to delude myself into thinking that some incremental gain in quantifiable performance even matters. I'm just riding bikes for fun. But if I were dropping over a grand on a 180mm fork, I'd for sure be looking at the competition before I blindly throw my cash at a 38, and in that case, the Bartlett and especially the boxxer are pretty hard to ignore.

    I see the point you're trying to make about all the geometry variables, but none of that matters. Change one variable at a time for your objective quantifiable analysis, remember? In this case, if you choose a boxxer over a single-crown, you can get 10-15mm of extra travel, without changing any other variable at all. The geo remains the same, but you have a little more travel on reserve... bonus. And that's in addition to the other advantages that the boxxer has over the 38, that you may or may not prefer to Kashima.

    I'll be on the edge of my seat awaiting the objective results of your double-blind back2back Mezzer-vs-38 test. Then we'll have definitive objective proof that the 38 is superior, when you shave 2 seconds off some Strava time that nobody cares about.

    Sorry to hear that you're defensive about buying a 38 based on marketing hype rather than thinking. That'd bug me too if I were you.

    Sent from my moto g(7) power using Tapatalk

  156. #156
    mtbr member
    Reputation:
    Join Date
    Dec 2008
    Posts
    550
    Quote Originally Posted by GT87 View Post
    The 'performance gain' thing is semamantics. Call it whatever you want. I definitely prefer modern hope v4/e4 disc brakes over old avid v-brakes. I prefer tubeless 2.5" tires over the shitty gumwall 1.8s on my first mtb. I would have even described them as having a performance advantage when riding tech terrain but I'm no scientist so I don't understand the terminology.

    I'm not going to delude myself into thinking that some incremental gain in quantifiable performance even matters. I'm just riding bikes for fun. But if I were dropping over a grand on a 180mm fork, I'd for sure be looking at the competition before I blindly throw my cash at a 38, and in that case, the Bartlett and especially the boxxer are pretty hard to ignore.

    I see the point you're trying to make about all the geometry variables, but none of that matters. Change one variable at a time for your objective quantifiable analysis, remember? In this case, if you choose a boxxer over a single-crown, you can get 10-15mm of extra travel, without changing any other variable at all. The geo remains the same, but you have a little more travel on reserve... bonus. And that's in addition to the other advantages that the boxxer has over the 38, that you may or may not prefer to Kashima.

    I'll be on the edge of my seat awaiting the objective results of your double-blind back2back Mezzer-vs-38 test. Then we'll have definitive objective proof that the 38 is superior, when you shave 2 seconds off some Strava time that nobody cares about.

    Sorry to hear that you're defensive about buying a 38 based on marketing hype rather than thinking. That'd bug me too if I were you.

    Sent from my moto g(7) power using Tapatalk
    i have a skeptical eye for every consumer product that is marketed....but thanks for giving me the advise. it's almost like somebody wants my money more than they want me to give it to somebody else. never saw that coming.

    in case you didn't notice, i haven't endorsed any one thing over another. the last thing i want to do is be responsible for leading somebody astray that has a different preference than me.

    your premise to change one variable at a time is sound. however suggesting that you can test a-c on its own by switching from an SC to a DC crown fork of differing manufacturers is flawed. they have different dampers, different springs, different weights, different lowers, different steerer tubes, different axles. you are swapping an entire system, not just a-c height. and you would have to guarantee that you rode the exact same line with the exact same body english at the exact same speed every time. you cannot possibly eliminate all the other variables.

    given the above, you would be well advised to not be sitting on the edge of your seat waiting for my feedback. there is no way i am going to claim to be able to do what you claim to be able to do. i am just not good enough to reduce a system down to a single variable. like you, i ride for fun. i buy stuff. i break a lot of stuff, and if do, i let the community now. some stuff i prefer. some stuff i don't. they only thing that has consistently made me better or faster is seat time.

    now, if you will excuse me, i am going to go peddle my 36lb long travel bike on a 31m road ride. i know, ill advised, but there is only so much you can down during the covid crisis, and getting smoked by lycra clad hammer heads is my soup du jour. hope you enjoy whatever soup du jour is keeping you sane as well.

    ***returning this back to constructive F38 data from the pissing match it has become.

  157. #157
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Ok cool story

  158. #158
    mtbr member
    Reputation:
    Join Date
    Dec 2017
    Posts
    83
    Using a longer travel fork doesn't keep the geometry the same.
    The important part of the geometry is at full compression. With 10mm more travel and the same a2c length your fork will now compress 10mm closer to the frame. This may be an issue as it can cause the tire to make contact with the frame and lock up. As the tire is closer to the frame at full compression your whole geometry has now changed. Your BB is lower and likely to hit the ground, and your head angle is now steeper, which can send you over the bars at the time when you have the most weight on the front.

    When modifying or building suspension the fully compressed and fully extended extremes are what need attention. Everything else inbetween is dynamic (unless you're just looking at the bike?) and will be a compromise based on the extremes.
    This is really basic stuff and I'm surprised it hasn't been mentioned yet.

  159. #159
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Welp, I'm glad I'm a lightweight hack rider that's content to stick with my Avy tuned Yari. If it's doing anything wrong, I'm not noticing. Worth noting it does feel better to me than my previous Fox 36 also Avy tuned, more precise steering with much better midrange support.

    But my original point remains, why would someone buy the 38 when the Boxxer appears to do everything but bar spins better? I'm sure the 38 is a great product but the physics of the matter point to better options than the 38. It seems to me it's just marketing. I'll run a DC for sure when I finally build that E- bike.

    To the point about 15mm of extra A2C, .6 degree here and there not mattering anyways...well frankly your on the wrong forum if you don't enjoy fretting over these minor details. They might be minor, but I can sure notice a preference on the trails of one over the other. Specifically I wouldn't except a smidge slacker STA at all to have any fork. And at 65 degrees HTA, well I consider that a tad too slack with no appreciable advantages over a 65.5 ish HTA, where-as the 65 has notable downsides in climbing performance Sag and springrate are uniform even when changing forks so to say 'suspension moves anyways' is absurd.

    And at full compression my tire is like 2" away from my frame, I'm really not worried about contact due to 10mm more travel. Of course I'd dump air pressure and verify clearance before riding, and add travel limiters as needed.

    The important part of geo certainly isn't at full compression, another absurd statement. Like we pedal, hit turns and jumps, etc at full compression. Just stop...




    Sent from my SM-G960U using Tapatalk
    Last edited by Suns_PSD; 04-19-2020 at 11:28 AM.

  160. #160
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by Suns_PSD View Post
    Welp, I'm glad I'm a lightweight hack rider that's content to stick with my Avy tuned Yari. If it's doing anything wrong, I'm not noticing. Worth noting it does feel better to me than my previous Fox 36 also Avy tuned, more precise steering with much better midrange support.

    But my original point remains, why would someone buy the 38 when the Boxxer appears to do everything but bar spins better? I'm sure the 38 is a great product but the physics of the matter point to better options than the 38. It seems to me it's just marketing. I'll run a DC for sure when I finally build that E- bike.

    To the point about 15mm of extra A2C, .6 degree here and there not mattering anyways...well frankly your on the wrong forum if you don't enjoy fretting over these minor details. They might be minor, but I can sure notice a preference on the trails of one over the other. Specifically I wouldn't except a smidge slacker STA at all to have any fork. And at 65 degrees HTA, well I consider that a tad too slack with no appreciable advantages over a 65.5 ish HTA, where-as the 65 has notable downsides in climbing performance Sag and springrate are uniform even when changing forks so to say 'suspension moves anyways' is absurd.

    And at full compression my tire is like 5" away from my frame, I'm really not worried about contact due to 10mm more travel.

    The important part of geo certainly isn't at full compression, another absurd statement. Like we pedal, hit turns and jumps, etc at full compression. Just stop...




    Sent from my SM-G960U using Tapatalk
    Well said!

    Coincidentally, just this week I scored a killer deal on a used yari with avy damper. Gonna send the cartridge back to Craig to have it re-tuned for me. Always wanted to try his damper but couldn't stomach the cost. Looking forward to it!

    Sent from my moto g(7) power using Tapatalk

  161. #161
    mtbr member
    Reputation: Dougal's Avatar
    Join Date
    Jan 2004
    Posts
    8,670
    Quote Originally Posted by GT87 View Post
    I don't know why you're so fixated on this axle to crown thing Dougal.
    I'm not. I'm asking why you guys are fixated on it. Which appears to be the dual-crown fork crowd mobbing this thread for some reason.

    Quote Originally Posted by GT87 View Post
    The lower a2c is one of the MULTIPLE reasons that the boxxer (or Bartlet if you're ok with 51 os) would be a better choice for this application, imo. If my frame were designed for a 180 SC (~593 a2c) then you could run the boxxer at 190 without changing the geo (assuming you don't want to change the geo) giving you 10mm of bonus travel with zero drawbacks...
    It's not zero draw-backs. Your bike ends up lower and steeper to get that full travel.

    Taking the same theory further, You can put a 170mm 27" fork and wheel in place of a 130mm 29" fork and wheel to have the same total height.

    Yes it's as silly as it sounds.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

  162. #162
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by Dougal View Post
    I'm not. I'm asking why you guys are fixated on it. Which appears to be the dual-crown fork crowd mobbing this thread for some reason.



    It's not zero draw-backs. Your bike ends up lower and steeper to get that full travel.

    Taking the same theory further, You can put a 170mm 27" fork and wheel in place of a 130mm 29" fork and wheel to have the same total height.

    Yes it's as silly as it sounds.
    For what it's worth, I'm not part of the "dual crown crowd", nor do i think that the dual crown crowd is mobbing this thread. I think it's more the "crowd that's willing to consider a dual crown if they're shopping for a 180mm fork". I don't think that crowd is fixated on the a2c, but we're willing to consider it as one (of many) factors when weighing the options. Then, you guys became fixated on trying to convince everyone that it's absurd to even consider a2c as a factor.

    The lower/steeper at bottom-out thing doesn't bother me. Hypothetically speaking, maybe you bottom out the 180mm fork harshly, when the 190mm DC had that little extra bit in reserve on the same hit. But that's kind of a silly hypothetical. For another silly hypothetical, we can follow your reasoning, and you could add a 10-15mm travel limiting spacer to your 180mm fork, preserving the static geometry, but ensuring that you bottom out sooner and don't get as steep and low at bottom-out... If we're following your logic, that would be better, right?

    Yes, your 170mm 27 fork vs 130mm 29 fork example is exactly as silly as it sounds.

    Sent from my moto g(7) power using Tapatalk

  163. #163
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Quote Originally Posted by GT87 View Post
    Well said!

    Coincidentally, just this week I scored a killer deal on a used yari with avy damper. Gonna send the cartridge back to Craig to have it re-tuned for me. Always wanted to try his damper but couldn't stomach the cost. Looking forward to it!

    Sent from my moto g(7) power using Tapatalk
    I'm a 180#s and I like to remove the cone shaped bumper in the negative chamber to increase negative volume in the Debonair, run 1 air volume spacer, Push fork seals, at exactly 100psi.
    Because it's so supportive now with the 100 psi (only possible to hit my 22% sag because neg chamber is larger) I'm finding I'm riding more forward on the bike and trusting the forks more than ever.
    Works so well!

    Sent from my SM-G960U using Tapatalk

  164. #164
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    FYI, a Mega w/ a Boxxer on Vital Bike Check.

    Looks awful I know...

    Sent from my SM-G960U using Tapatalk

  165. #165
    mtbr member
    Reputation:
    Join Date
    Mar 2014
    Posts
    810
    Quote Originally Posted by Suns_PSD View Post
    FYI, a Mega w/ a Boxxer on Vital Bike Check.

    Looks awful I know...

    Sent from my SM-G960U using Tapatalk
    Head angle will be too steep when he uses full travel

  166. #166
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Quote Originally Posted by GT87 View Post
    Head angle will be too steep when he uses full travel
    Ya, he'll OTB for sure.

    Half a degree of HTA is meaningless while riding the new 38, until it means everything when bottoming your Boxxer.

  167. #167
    mtbr member
    Reputation:
    Join Date
    Nov 2009
    Posts
    2,994
    I looked in here thinking it was a Fox 36 thread...

  168. #168
    mtbr member
    Reputation:
    Join Date
    Dec 2004
    Posts
    225
    Got it bolted on and went for my standard Fork/New bike break in lap. A mix of tech climbing and quick but tech descending.

    The 38 seems to live up to it's marketing. It's stiffer. The damper is similar but feels more plush. Interesting that it requires more pressure for a given sag. On my '20 36 I ran about 75 psi, where as with this 38 it required 102 for "plush" setup.

    It definitely sits taller, as mentioned above. I will be dropping my bar height a bit on my next ride.

    Looking forward to a bunch of tech gnar and fast rowdy trails on this fork.


  169. #169
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    849
    Quote Originally Posted by partswhore View Post
    Interesting that it requires more pressure for a given sag. On my '20 36 I ran about 75 psi, where as with this 38 it required 102 for "plush" setup.
    It's using the 34 air piston or something like that. Smaller piston means you need more pressure for a given force.

  170. #170
    mtbr member
    Reputation:
    Join Date
    Apr 2018
    Posts
    1,498
    Looks burly.

    i may have started the DC v SC thing here. i wasn't intending to literally compare an OTS boxxer to the 38. i just think from a development standpoint, 38mil SCs seem to be pushing the envelope of what makes sense for a SC fork. all the longitudinal flex. less of the lateral. more mass inherently used less efficiently. 35mm DC gives a bit more of the opposite. which is what i'd want if i was in the market for a competition-grade mtb fork. a little bit of flex in the right places is good. flat trackers don't use Superbike forks, for instance.

    clamps are easy to machine and easy to change offset and A2C with. RS sliders could be a bit longer i guess, but lawyers..

  171. #171
    mtbr member
    Reputation:
    Join Date
    Dec 2008
    Posts
    550
    Quote Originally Posted by PhillipJ View Post
    It's using the 34 air piston or something like that. Smaller piston means you need more pressure for a given force.
    right. the piston rides in an sleeve within the stanchion, which reduces inner stanchion diameter. reduced inner stanchion diameter reduces inner stanchion area, thus requiring more pressure to achieve the same support.

    going to paraphrase off of memory here, but i believe the sleeve actually floats, (potentially) allowing some small degree of travel while the piston is overcoming the its stiction to break away. also, with the reduced circumference of the smaller diameter piston, there should [theoretically] be less break away force. theoretically, this should allow for more small bump sensitivity?

  172. #172
    change is good
    Reputation:
    Join Date
    Sep 2004
    Posts
    2,995
    Quote Originally Posted by FactoryMatt View Post
    Looks burly.

    i may have started the DC v SC thing here. i wasn't intending to literally compare an OTS boxxer to the 38. i just think from a development standpoint, 38mil SCs seem to be pushing the envelope of what makes sense for a SC fork. all the longitudinal flex. less of the lateral. more mass inherently used less efficiently. 35mm DC gives a bit more of the opposite. which is what i'd want if i was in the market for a competition-grade mtb fork. a little bit of flex in the right places is good. flat trackers don't use Superbike forks, for instance.

    clamps are easy to machine and easy to change offset and A2C with. RS sliders could be a bit longer i guess, but lawyers..
    I used a Maverick DUC fork before so Iím open to that format, although that fork because it was inverted and light was a POS. Because Iím heavy Iíve always put a burlier fork on my bike than what it was speced with. Iím on the fence with this one since I donít take chances as often as I used to.


    Sent from my iPad using Tapatalk Pro

  173. #173
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Quote Originally Posted by partswhore View Post
    Got it bolted on and went for my standard Fork/New bike break in lap. A mix of tech climbing and quick but tech descending.

    The 38 seems to live up to it's marketing. It's stiffer. The damper is similar but feels more plush. Interesting that it requires more pressure for a given sag. On my '20 36 I ran about 75 psi, where as with this 38 it required 102 for "plush" setup.

    It definitely sits taller, as mentioned above. I will be dropping my bar height a bit on my next ride.

    Looking forward to a bunch of tech gnar and fast rowdy trails on this fork.

    Looks sharp. The angle of that photo makes the front end look really high.

    Keep us in the loop on how it performs including effects on geo.

    As far as the 38 vs. the DC argument, it's time to take that to a different thread (and I'm in the DC camp) imo as this thread is for those that have chosen the 38.

    Sent from my SM-G960U using Tapatalk

  174. #174
    mtbr member
    Reputation:
    Join Date
    Dec 2004
    Posts
    225
    Quote Originally Posted by Suns_PSD View Post
    Looks sharp. The angle of that photo makes the front end look really high.

    Keep us in the loop on how it performs including effects on geo.

    As far as the 38 vs. the DC argument, it's time to take that to a different thread (and I'm in the DC camp) imo as this thread is for those that have chosen the 38.

    Sent from my SM-G960U using Tapatalk
    It certainly was noticeable.

    I'm hoping the 5mm stem drop I did remedies the geo feel. I do have another ~5mm (depending on stem/top cap interference) to work with.

  175. #175
    Elitest thrill junkie
    Reputation: Jayem's Avatar
    Join Date
    Jul 2005
    Posts
    34,134
    Quote Originally Posted by DrDon View Post
    I used a Maverick DUC fork before so Iím open to that format, although that fork because it was inverted and light was a POS.
    Yeah, that fork is not indicative of DC forks. They tried to address the torsional flex of inverted, like every company before and after has, but it's always inherently fliexier. Right-side-up DC on the other hand, massive torsional stiffness, in addition to every other direction.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  176. #176
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Quote Originally Posted by partswhore View Post
    It certainly was noticeable.

    I'm hoping the 5mm stem drop I did remedies the geo feel. I do have another ~5mm (depending on stem/top cap interference) to work with.
    You can certainly correct the handlebar height easily enough, however unless you run excessive sag on the 38, your HTA/ STA & BB will be different than it was with your other fork. Maybe those changes are advantageous in this particular circumstance.
    That's why A2C matters, particularly on a retrofit.

    Sent from my SM-G960U using Tapatalk

  177. #177
    mtbr member
    Reputation:
    Join Date
    Dec 2004
    Posts
    225
    Funny thing. I took a tape measure to both forks tonight. The first being a 2020 36, 160mm and the second being a 2021 38, 160mm.

    They measured the same A2C height. +/- a mm.

    So perhaps what I was feeling was just the fork riding higher in its travel? I'll have to go smash on it a bit more and figure it out.

  178. #178
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    3,180
    Quote Originally Posted by partswhore View Post
    Funny thing. I took a tape measure to both forks tonight. The first being a 2020 36, 160mm and the second being a 2021 38, 160mm.

    They measured the same A2C height. +/- a mm.

    So perhaps what I was feeling was just the fork riding higher in its travel? I'll have to go smash on it a bit more and figure it out.
    It should be a 7mm difference according to Fox, basically 1/3" of an inch. Not much really, but then not nothing either.
    You'll forget about it after a ride or 3.
    Heck it might just be set up with less sag than your 36, or the 38 might just naturally have more support in the midrange holding it up higher.

    Sent from my SM-G960U using Tapatalk

  179. #179
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    The 2021 Forks spec sheets are now available

    https://www.ridefox.com/fox17/help.p...all=specsheets


  180. #180
    mtbr member
    Reputation:
    Join Date
    Dec 2008
    Posts
    550
    +/- 5mm of A2C height listed on all schematics, 2017-20 F36, 21 F36 and 21 F38.

    just for fun since this such hotly debate topic over an absolutely critical measure:

    20 F36 (+5) vs 21 F36 (-5) = 572.1mm vs 566mm
    21 F36 (+5) vs 21 F38 (-5) = 576mm vs 568.7mm
    20 F36 (+5) vs 21 F38 (-5) = 572.1mm vs 568.7mm

    all of these numbers are based off of 160mm travel settings, and in all cases its possible for the legacy F36 to arrive from the factory with a higher A2C than an F38 and still be completely within normal tolerances. so theoretically, that legacy fork could have a slacker HA than the new 2021 wares. of course, the opposite is also true, but without measuring, as partswhore did, we may never know.

    hairs, you have been split.

  181. #181
    mtbr member
    Reputation:
    Join Date
    Jun 2018
    Posts
    18
    Sorry to interrupt the a2c debate, which I find very interesting btw. Is it confirmed that a 180mm F38 will be able to reduce travel to 170 by changing the air shaft?

    About to pull the trigger on a 180 since 170 seems to be only a myth and impossible to get one quick.

  182. #182
    mtbr member
    Reputation:
    Join Date
    Dec 2004
    Posts
    1,474
    Quote Originally Posted by Soucy View Post
    Sorry to interrupt the a2c debate, which I find very interesting btw. Is it confirmed that a 180mm F38 will be able to reduce travel to 170 by changing the air shaft?

    About to pull the trigger on a 180 since 170 seems to be only a myth and impossible to get one quick.
    Speaking of air shafts... I don't see anything online about parts to change travel on the 38s. Anyone know anything about it?
    Kona Operator CR and Santa Cruz Megatower

  183. #183
    mtbr member
    Reputation:
    Join Date
    Mar 2019
    Posts
    1,501
    Quote Originally Posted by Christopher Robin View Post
    Speaking of air shafts... I don't see anything online about parts to change travel on the 38s. Anyone know anything about it?
    It hasnít been published yet! Same for the new X2 and DHX2.

  184. #184
    change is good
    Reputation:
    Join Date
    Sep 2004
    Posts
    2,995
    Quote Originally Posted by Soucy View Post
    Sorry to interrupt the a2c debate, which I find very interesting btw. Is it confirmed that a 180mm F38 will be able to reduce travel to 170 by changing the air shaft?

    About to pull the trigger on a 180 since 170 seems to be only a myth and impossible to get one quick.
    I called Fox. They informed me that one can change the travel with air shafts.


    Sent from my iPad using Tapatalk Pro

  185. #185
    mtbr member
    Reputation:
    Join Date
    Dec 2004
    Posts
    1,474
    Ok good... but I suppose it'll take Fox a little while to catch up and post up part numbers and prices on said air shafts.
    Kona Operator CR and Santa Cruz Megatower

  186. #186
    mtbr member
    Reputation:
    Join Date
    Dec 2018
    Posts
    333
    Any Aussies got theirs yet? This covid seems to be delaying things.

    The price is eye watering here too. Our dollar vs the USD is dismal at the moment.

  187. #187
    mtbr member
    Reputation: kwapik's Avatar
    Join Date
    Feb 2016
    Posts
    542
    Quote Originally Posted by brash View Post
    Our dollar vs the USD is dismal at the moment.
    I remember when it was the opposite. I'd have Australians coming over to purchase Ford cars and parts because the AUD had more buying power.

  188. #188
    mtbr member
    Reputation:
    Join Date
    Dec 2018
    Posts
    333
    Quote Originally Posted by kwapik View Post
    I remember when it was the opposite. I'd have Australians coming over to purchase Ford cars and parts because the AUD had more buying power.
    yep, we had parity dollar for dollar maybe 10 years ago. I bought myself a 1955 Panhead harley davidson for next to nothing comparitive to local prices.

  189. #189
    mtbr member
    Reputation:
    Join Date
    Nov 2014
    Posts
    479
    Steve from Vorsprung posted a video on the 38 this morning including a full tear down and some dyno plots comparing it to the original GRIP2 and older RC2 dampers. Definitely worth checking out if you're interested in this kind of stuff or considering an upgrade.
    https://www.youtube.com/watch?v=lS-VzI2JbrI

  190. #190
    Formerly PaintPeelinPbody
    Reputation: PHeller's Avatar
    Join Date
    Dec 2012
    Posts
    2,713
    Kinda what I suspected. The 38 is more of a marketing swing then a technical home run. It's not really revolutionary, but more evolutionary. The air spring floating tube is cool, though, and it might be interesting to see if that finds it's way into a 36 later on. Would also be cool to see the GRIP2 VVC 36 compared against the 38 to see if that Floating Air Spring makes a big difference in initial stroke suppleness.

    The Vorsprung video does certainly illustrate why the GRIP2 was firmer!
    Work - Utility GIS Analyst
    Party - 2019 Guerrilla Gravity Revved Trail Pistol Sz 3

  191. #191
    mtbr member
    Reputation:
    Join Date
    Dec 2004
    Posts
    1,474
    I agree... while I'm guilty of falling prey to Fox's marketing (I bought a Factory 38 in 180mm), I was at least sorta needing/wanting a new fork. I'm still messing with the air spring but it feels decent and I actually like the 15mm QR, since I have to take my wheel off every time I store my bike after a ride. I quite like the Fox's chassis...they're always smooth. I'll have to check to see if my steerer is in straight, otherwise it's up to my local Fox warranty center! hahaha.

    I'm sure Steve over at Vorsprung and others will be coming out of the woodwork offering to undo Fox's damping debacle.
    Kona Operator CR and Santa Cruz Megatower

  192. #192
    mtbr member
    Reputation: kwapik's Avatar
    Join Date
    Feb 2016
    Posts
    542
    Informative video as usual. I do think the floating tube design will trickle down to the 36. And yeah, suspension shops will probably offer improved 38 damper tunes.

  193. #193
    mtbr member
    Reputation: jeremy3220's Avatar
    Join Date
    Jul 2017
    Posts
    2,843
    Interesting about the compression range. I wonder if all the pros have to run firmer tunes to get the support they need.

  194. #194
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by PHeller View Post

    The Vorsprung video does certainly illustrate why the GRIP2 was firmer!
    I'm always interested in what everyone takes out of a presentation like this, there is always some confirmation bias no matter how its diaplayed.

    Even though the potential damping force was really high, the steps between clicks aren't even so 90% of people run their grip2 forks somewhere closer to that bottom line which isn't firm at all
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  195. #195
    mtbr member
    Reputation: jeremy3220's Avatar
    Join Date
    Jul 2017
    Posts
    2,843
    Quote Originally Posted by JohnnyC7 View Post
    I'm always interested in what everyone takes out of a presentation like this, there is always some confirmation bias no matter how its diaplayed.

    Even though the potential damping force was really high, the steps between clicks aren't even so 90% of people run their grip2 forks somewhere closer to that bottom line which isn't firm at all
    Yeah, the reality is it probably won't be an issue for most riders.

  196. #196
    mtbr member
    Reputation:
    Join Date
    Nov 2009
    Posts
    2,994
    Quote Originally Posted by PHeller View Post
    Kinda what I suspected. The 38 is more of a marketing swing then a technical home run. It's not really revolutionary, but more evolutionary. The air spring floating tube is cool, though, and it might be interesting to see if that finds it's way into a 36 later on. Would also be cool to see the GRIP2 VVC 36 compared against the 38 to see if that Floating Air Spring makes a big difference in initial stroke suppleness.

    The Vorsprung video does certainly illustrate why the GRIP2 was firmer!
    The new 36 also have a larger negative air spring.

  197. #197
    mtbr member
    Reputation:
    Join Date
    Nov 2009
    Posts
    2,994
    Quote Originally Posted by jeremy3220 View Post
    Interesting about the compression range. I wonder if all the pros have to run firmer tunes to get the support they need.
    95% of pro riders are just on stock suspension, only the very top echelon are on anything different to stock.

  198. #198
    mtbr member
    Reputation: Millennial29erGuy's Avatar
    Join Date
    Feb 2017
    Posts
    1,651
    Quote Originally Posted by JohnnyC7 View Post
    ...the steps between clicks aren't even so 90% of people run their grip2 forks somewhere closer to that bottom line which isn't firm at all
    This is one thing I was wondering after watching his video. Do you have any feedback on whether or not this VVC compression damper would work for me?

    I am 108kg
    running 106 psi in the 2020 F36
    HSC: -6 from closed
    LSC: -4
    HSR: -4
    LSR: -3
    My name is George. Iím unemployed and I live with my parents.
    2017 BMC Speedfox 25-622 ISO
    2017 Salsa Timberjack 40-584 ISO

  199. #199
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,435
    Quote Originally Posted by the_joe View Post
    This is one thing I was wondering after watching his video. Do you have any feedback on whether or not this VVC compression damper would work for me?

    I am 108kg
    running 106 psi in the 2020 F36
    HSC: -6 from closed
    LSC: -4
    HSR: -4
    LSR: -3
    I haven't been able to get my hands on the new fork yet but going by Steve's video you will have significantly less damping even with the adjusters closed. There might be scope for tuning, but as he mentioned it is very sensitive to stack height, and shim stacks don't always behave as predicted so I can't say it can be fixed until I actually get one and dyno it.
    www.thesuspensionlab.nz
    Suspension servicing & tuning in Rotorua, NZ/Vorsprung Elite Tuning Centre/Insta @thesuspensionlab

  200. #200
    mtbr member
    Reputation: Millennial29erGuy's Avatar
    Join Date
    Feb 2017
    Posts
    1,651
    Quote Originally Posted by JohnnyC7 View Post
    I haven't been able to get my hands on the new fork yet but going by Steve's video you will have significantly less damping even with the adjusters closed. There might be scope for tuning, but as he mentioned it is very sensitive to stack height, and shim stacks don't always behave as predicted so I can't say it can be fixed until I actually get one and dyno it.
    cool, thanks
    My name is George. Iím unemployed and I live with my parents.
    2017 BMC Speedfox 25-622 ISO
    2017 Salsa Timberjack 40-584 ISO

Page 1 of 2 12 LastLast

Similar Threads

  1. change 38/26 to 38/24 using the same 38T chain ring
    By 156flash in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 2
    Last Post: 03-08-2017, 06:11 AM
  2. Replies: 6
    Last Post: 08-26-2013, 01:15 AM
  3. XTR M980 38/26: new chain rings and 38/24 combo
    By Hawgzilla in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 19
    Last Post: 07-23-2013, 12:29 PM
  4. Shimano XT 2x10 - Does it matter if a 38 AM chainring is used instead of a 38 AK?
    By skyno in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 5
    Last Post: 07-13-2013, 04:16 PM
  5. Convert Shimano XT 785 38-26 to 38-24
    By Danish Dynamite in forum Shimano
    Replies: 1
    Last Post: 04-15-2012, 02:32 PM

Members who have read this thread: 620

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2020 VerticalScope Inc. All rights reserved.