Jet9 design flaw? (front derailleur mount)- Mtbr.com
Results 1 to 28 of 28
  1. #1
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    16

    Jet9 design flaw? (front derailleur mount)

    Anyone got this same issue?
    (2x10 shimano XT)
    When I am using the low gear in the front and high gear in the back (small in front and small in back), the chain rubs against the base of the front derailleur (actually for gears 7-8-9-10 in the back).
    I tried to lower the position of the whole front derailleur, but to my surprise, the this is already at the lowest position.
    It seems the mount is too high on the frame.
    Anyone got this too?
    I don't plan to use the lower gear in front and the 8th gear back, but I though that in a $4k bike this should not happen.
    thx.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Nov 2011
    Posts
    3,779
    Depends on the chainrings and the derailleur model. And running small-small is not usual.

  3. #3
    mtbr member
    Reputation: SlowPokePete's Avatar
    Join Date
    Mar 2006
    Posts
    1,586
    Quote Originally Posted by czaniolo View Post
    Anyone got this same issue?
    (2x10 shimano XT)
    When I am using the low gear in the front and high gear in the back (small in front and small in back), the chain rubs against the base of the front derailleur (actually for gears 7-8-9-10 in the back).
    I tried to lower the position of the whole front derailleur, but to my surprise, the this is already at the lowest position.
    It seems the mount is too high on the frame.
    Anyone got this too?
    I don't plan to use the lower gear in front and the 8th gear back, but I though that in a $4k bike this should not happen.
    thx.
    That is a crossover gear and you should not be using it.

    It causes a far off chain line which will wear your drivetrain more quickly.

    You can closely duplicate the gear ratio you are trying to obtain by using the big ring in front and a larger cog on your cassette, which is the reason why there is no reason to be in that gear in the first place.

    This has nothing to do with a design flaw...

    SPP
    Rigid.

  4. #4
    mtbr member
    Reputation: LyNx's Avatar
    Join Date
    Oct 2004
    Posts
    24,080
    Welcome to the world of MTB cycling, it is very fun and provides a good workout. In time you will look back on this thread post and laugh at how silly you were, in the meantime we'll do that for you Hang about here some more, do some reading and research and learn what gear combos are consider good and what are bad, learn about shifting and using ring/cog combos properly.

    Besides the fact that you are talking about using gear combos that would severly crosschain, causing premature chain stretch and wear and gear combos known not to be useable anyways, did you let all the air out of your shock and cycle the suspension to it's maxx? If you'd done this you would have seen that the clearance between the chainstay and the FD is very minimal, any lower and the chainstay would probably bash into the FD.
    Quote Originally Posted by Harold
    You're doing mtbr wrong, you're supposed to get increasingly offended by the implications that you're doing ANYTHING wrong.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    16
    I appreciate the responses, but...
    I don't know why some of you is focusing in 'if I should be using that combination of gears'. I told in the original that I don't plan to use that.
    But even if I will not use small in the front and 8th in the back, that does not mean that it is OK to rub to the derailleur. In every video on youtube on how to adjust the derailleur, every bike can go to the whole spread of combinations without any rub to the front derailleur.
    Let's not focus on the wrong point.
    The point is: will the thing work without rubbing or not. If it's something about the setting, I should be able to fix it.
    If it's not the setting, it must be a design flaw.

  6. #6
    AZ
    AZ is offline
    banned
    Reputation: AZ's Avatar
    Join Date
    Apr 2009
    Posts
    19,198
    Quote Originally Posted by czaniolo View Post
    I appreciate the responses, but...
    I don't know why some of you is focusing in 'if I should be using that combination of gears'. I told in the original that I don't plan to use that.
    But even if I will not use small in the front and 8th in the back, that does not mean that it is OK to rub to the derailleur. In every video on youtube on how to adjust the derailleur, every bike can go to the whole spread of combinations without any rub to the front derailleur.
    Let's not focus on the wrong point.
    The point is: will the thing work without rubbing or not. If it's something about the setting, I should be able to fix it.
    If it's not the setting, it must be a design flaw.


    It is a design compromise and with your obviously tightly knotted panties I'd suggest a different pursuit as mountain biking/mountain bikers are usually pretty laid back and more understanding of compromises.

  7. #7
    mtbr member
    Reputation:
    Join Date
    Jul 2011
    Posts
    8,586
    Quote Originally Posted by czaniolo View Post
    I appreciate the responses, but...
    I don't know why some of you is focusing in 'if I should be using that combination of gears'. I told in the original that I don't plan to use that.
    But even if I will not use small in the front and 8th in the back, that does not mean that it is OK to rub to the derailleur. In every video on youtube on how to adjust the derailleur, every bike can go to the whole spread of combinations without any rub to the front derailleur.
    Let's not focus on the wrong point.
    The point is: will the thing work without rubbing or not. If it's something about the setting, I should be able to fix it.
    If it's not the setting, it must be a design flaw.

    I'd suggest as a new person to mountain biking you listen to the advice of others that have been doing it a lot longer.
    The point to focus on is the fact that it's cross chaining and you shouldn't do it period. If you know better, then why are you asking on here?
    Ripley LS v3
    OG Ripley v2 handed down to son

  8. #8
    mtbr member
    Reputation: 11053's Avatar
    Join Date
    Sep 2009
    Posts
    2,413
    Does it rub when riding, or is it when you are going through the gears when the bike is in the stand?
    When the rear suspension is compressed a bit, does the rubbing go away?
    Some full suspension frames + gear combos + chainring sizes will allow for rub on the bottom of the front derailleur in non optimal gears when the bike is in the stand or when you are not running enough sag in the suspension.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    16
    Thanks Norman,
    First decent technical response that actually adds any information instead of just whining/flaming.
    When I'm riding the rubbing gets a lot better (meaning less).
    From the videos that I saw, I saw no rubbing whatsoever even on the stand. So I found it strange when I could not get rid of the rubbing.
    The other bikes that I had did not rub at all (even if I don't list them on the end of my posts).
    To all others: if you wanna tell how good you are ... go brag to your mommys. Don't bother to respond.

  10. #10
    mtbr member
    Reputation:
    Join Date
    Nov 2011
    Posts
    3,779
    As I said in the very first post - Depends on the chainrings and the derailleur model.
    What size chainrings are you running and what model of derailleur?

  11. #11
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    29
    I think you guys are being a bit harsh. There shouldn't be chainrub on the last 4 gears. On extreme combinations it's not unusual, but that is excessive. I think Norman is on to something here, when the rear suspension is compressed the chainline should be higher, therefore reducing rub.

  12. #12
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    16
    Slash5 - its 11 in the back and 26 in the front.
    Shimano XT.
    thanks.

    I rode a bit today even if the snow is heavy, there is just a bit of rubbing on the 8th 9th and 10th and not rubbing in any gear when I'm using the big crank.
    On the stand it was kind of too much.
    Riding it isn't.

  13. #13
    banned
    Reputation:
    Join Date
    Sep 2010
    Posts
    1,267
    Quote Originally Posted by Bathwater View Post
    I think you guys are being a bit harsh. There shouldn't be chainrub on the last 4 gears. On extreme combinations it's not unusual, but that is excessive. I think Norman is on to something here, when the rear suspension is compressed the chainline should be higher, therefore reducing rub.


    Yeah, the internets are usually harsh, and cold, especially when some critical thinker comes on here and throws a company under the bus when the real issue is parts selection or execution of the setup. Thousands of these have been sold, apparently without hordes of people posting about this very "design flaw" so maybe you and "Norman" can get together and brainstorm a fix and save us all from an obviously well thought out plan to screw us all. Flame away.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    29
    Quote Originally Posted by floydlippencott View Post
    Yeah, the internets are usually harsh, and cold, especially when some critical thinker comes on here and throws a company under the bus when the real issue is parts selection or execution of the setup. Thousands of these have been sold, apparently without hordes of people posting about this very "design flaw" so maybe you and "Norman" can get together and brainstorm a fix and save us all from an obviously well thought out plan to screw us all. Flame away.
    Lol, Jesus, dude. My post never implied anything inherently wrong with Niner frames. In fact, the opposite. Like I indicated towards, during normal riding conditions, the drivetrain should be operating properly.

  15. #15
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    16
    floydlippencot - great companies also do design flaws. A lot of them.
    You're just naive. Also, the parts selection is also done by Niner, so I don't see your point.

    Having said that, the bike is great. (it's true, but I'm just saying it now to calm the feet stamping babies).

  16. #16
    mtbr member
    Reputation:
    Join Date
    Nov 2011
    Posts
    3,779
    Quote Originally Posted by czaniolo View Post
    Slash5 - its 11 in the back and 26 in the front.
    Shimano XT.
    thanks.
    .
    Need the large front chainring size and the small front chainring size.
    Need the actual model # of the derailleur.
    For example, the FD-M785-E2 derailleur has a capacity of 12 teeth. The FD-781-D has 18 teeth.

    The derailleur may have been speced the way it is to provide rear tire or chain stay clearance. Full suspension designs require some compromises. Even on my hardtail I can't put my front derailleur in exactly the optimal spot or it rubs on the tire.

  17. #17
    banned
    Reputation:
    Join Date
    Sep 2010
    Posts
    1,267
    Like I posted above, its your execution. Speaking of Babies, you are the one that started the unnecessary crying.

  18. #18
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    16
    front shim xt M780 I-spec 10 speed
    chain HG-95 10sp

    the way that came from Niner, I did not alter.

    thx.

  19. #19
    mtbr member
    Reputation: 11053's Avatar
    Join Date
    Sep 2009
    Posts
    2,413
    Check the chain length as well.
    If the chain is a bit too long, the rear derailleur may not be able to provide enough tension/wrap on the chain in those small + small gear combos.
    Park Tool Co. ParkTool Blog Chain Length Sizing
    Those aren't optimal gear combos as you know, but I bet you can get the bike set up so there's no rub when you are riding.

  20. #20
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    16
    Thanks again Norman. The chain is on the long side indeed. I'm not sure if if will change the chain length now, since I don't plan to use small+small. But it makes a big difference to know the source of the thing.
    floydlippencot - yes it could be mine (or my dealer's) execution, that is exactly why I posted the title as a question, not a statement. Ask your high school teacher (if you've been through that already) the difference between a statement and a question. Take the chance and explain the same to your whining friends.

  21. #21
    mtbr member
    Reputation: bikeguru1's Avatar
    Join Date
    Nov 2004
    Posts
    27
    I'm a Niner dealer and have found that when setting up both the Jet and the Rip with the same derailleur and gear combo that you are using that your described issue can indeed occur. With the current 2x trend and especially Shimano's use of 26/38 gearing, riders want to use most if not all of the 20 available gears. In the high alpine of the Rockies a 22/36 or lower combos can exaggerate your problem. When setting it all up pay special attention to bottom bracket spacer positions, FD cable tension, 2x or 3x shifter "switch" position and lastly make sure that when tightening the rear FD to frame allen bolt that the rear of the cage of the FD doesn't "pivot" up on the front screw. I have had to pull the crank to properly tighten that front screw and have also found on more than one occasion that the supplied allens were too long. As stated before, sag and chain length as well as B tension all plays into the proper set up for rub free riding.
    Good luck - you'll love that bike.
    Sun Summit South in Hailey, Idaho
    http://crankandcarve.webs.com/

  22. #22
    mtbr member
    Reputation: squareback's Avatar
    Join Date
    Sep 2011
    Posts
    1,519
    This is how a person contributes to a forum:


    Quote Originally Posted by bikeguru1 View Post
    I'm a Niner dealer and have found that when setting up both the Jet and the Rip with the same derailleur and gear combo that you are using that your described issue can indeed occur. With the current 2x trend and especially Shimano's use of 26/38 gearing, riders want to use most if not all of the 20 available gears. In the high alpine of the Rockies a 22/36 or lower combos can exaggerate your problem. When setting it all up pay special attention to bottom bracket spacer positions, FD cable tension, 2x or 3x shifter "switch" position and lastly make sure that when tightening the rear FD to frame allen bolt that the rear of the cage of the FD doesn't "pivot" up on the front screw. I have had to pull the crank to properly tighten that front screw and have also found on more than one occasion that the supplied allens were too long. As stated before, sag and chain length as well as B tension all plays into the proper set up for rub free riding.
    Good luck - you'll love that bike.

  23. #23
    mtbr member
    Reputation: DethWshBkr's Avatar
    Join Date
    Nov 2010
    Posts
    2,402
    I'm a little surprised by some of these responses as well.

    We go from a 3x8 to 2x10 a 1x11 type setup, and we say you can't use some of your gears?
    Wow.

    I don't see why a chain should EVER RUB the bottom of the front deraileur. SIDES, yes, you MAY RUB on extreme gears (another reason I like Grip Shift - adjustable side to side without shifting!)
    the low gear in the front and high gear in the back
    Thats due to the size of the chainring mostly. As the guy prior said, smaller front chainrings will cause this to be more evident.
    How much clearance does the deraileur have to the chainring? COULD it go lower? (assuming there was more "throw" in the mount - would the plates hit a ring?)


    As an old school MTB rider, I am seeing a lot of things in the market that "solve" problems that really are not problems, or that we solved in the mid 90's by riding techniques, not fancy stuff. Seems when you bring it up, people act like you don't have a clue what you are talking about.

  24. #24
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    16
    The derailleur cannot go lower. It's at its lowest.
    I am pretty sure that if the mount could go 5mm lower (on the posterior side only - tilting it slightly counterclockwise), the problem would be resolved for good.
    And I doubt that that would affect negatively the shifting.

    But like I said, when I'm riding it's not bad at all. It's only when the bike is up the stand. I found it fruitful to read the useful comments that some people posted.

    I was indeed surprised with the quantity of people that is here only for bragging.
    The forum is to exchange useful information and povs. I don't get these guys that are here just to brag. Really. Get a life.
    Listing the bikes you had?? C'mon what's that?
    I will list the things that I have...

    Allen 5mm wrench (silver)
    Old cheap sunglasses that fog for nothing
    Nice bag of microfiber rags from Costco (great to clean the bike)
    ...ha ha ha

  25. #25
    mtbr member
    Reputation:
    Join Date
    Jul 2011
    Posts
    8,586
    Quote Originally Posted by czaniolo View Post
    The derailleur cannot go lower. It's at its lowest.
    I am pretty sure that if the mount could go 5mm lower (on the posterior side only - tilting it slightly counterclockwise), the problem would be resolved for good.
    And I doubt that that would affect negatively the shifting.

    But like I said, when I'm riding it's not bad at all. It's only when the bike is up the stand. I found it fruitful to read the useful comments that some people posted.

    I was indeed surprised with the quantity of people that is here only for bragging.
    The forum is to exchange useful information and povs. I don't get these guys that are here just to brag. Really. Get a life.
    Listing the bikes you had?? C'mon what's that?
    I will list the things that I have...

    Allen 5mm wrench (silver)
    Old cheap sunglasses that fog for nothing
    Nice bag of microfiber rags from Costco (great to clean the bike)
    ...ha ha ha
    It appears you're new to forums.
    You title is what got you flamed. The ? at the end didn't change the ignorance in titling it design flaw.

    Second if you think listing bikes is about bragging- too funny. The bikes I've had are nothing to brag about, it does however give someone perspective on what I've ridden extensively when I give my opinion on something.
    Ripley LS v3
    OG Ripley v2 handed down to son

  26. #26
    mtbr member
    Reputation:
    Join Date
    Dec 2012
    Posts
    16
    ha ha... I knew you would respond to that....
    Too bad it also gives a perspective on who you are.
    Just my opinion, don't take it bad.

    I got flamed but also I got a lot of good info.
    Without the "?" I probably wouldn't have any. See my point?

    And yet...I can make fun of the flamers!!

    Have fun my friend.

  27. #27
    mtbr member
    Reputation: bikeguru1's Avatar
    Join Date
    Nov 2004
    Posts
    27
    Gearing talk on MTBR really brings out the egos. If my conversation at Interbike this fall with Chris, the owner of Niner, is of any indication of a common mindset or at the very least a misconception that modern gearing is adequately low enough. I suggested that there should be two sets of direct mount holes - one for "Sea Otter" gearing (26/38 and higher) and one for "Alpine" gearing (22/36 and lower). I am currently running a Middleburn crank with a 58/94 BCD and 20/30/Bash on my 2014 RIP. Behind my Raceface BB cups I have a .7mm spacer driveside and 1.8mm on the non drive. I have a Sram X0 22/36 FD all mated up to XTR shifters and RD and an 11/36 XT cassette. Quite a cluster. My first gear is a bail out and when needed it sure is nice to have it. My top end is spun out at 27 mph - plenty fast for single track. I don't use the 11 or 12 when on the small ring opting to jump to the "big" ring and I have no rubbing or extra wear on the 30/36 combo that I about live in while the "Sea Otter" guys are bailing to their "small" rings and my momentum carries on. It made sense to Chris when explained that way but then he exclaimed his liking of the 1x and the demise of the FD and left shifter all together. Unfortunately the new XO 1x BCD only allows a 30 tooth and the XX1's 28 tooth is still higher than my set up. Even though the plethora of retro 38, 40 and 42 cogs by WTC, Endless and the likes are supposedly for 1x systems they will provide for many riders running 2x and even 3x (gasp!) and who have longed for lower gearing out back - even if they are running "Sea Otter" dhainrings. Just like Nino and Julian. Sorry for the thread jack, just coudn't help myself. Flame on! Where is Bruce Brown when you need him? Lets get Muzzinac in here too!
    Sun Summit South in Hailey, Idaho
    http://crankandcarve.webs.com/

  28. #28
    Carbon & Ti rule
    Reputation: muzzanic's Avatar
    Join Date
    Apr 2009
    Posts
    5,410
    Yep I don't know what planet sram was on when they choose to make the XO1 only go down to 30 when the XX1 already went down to 28.

    I run a 28 tooth front ring on my Rip9 RDO with XX1 & a 26 wolf tooth front ring on my Rip9 Alloy with X01

    I have a 42 Endless rear ring coming to try on 1 of my 10 speed bikes.

    I have played with gearing a lot & IMO a lot of people think they need taller gearing than they do, with the 26 front ring I do run at high rev's from time to time but not that often & the amount of time you make up elsewhere will more than make up for it.

    I have run my XX1 cassette on a 10 speed geared bike or 2 & had it work fine Some not quite as good.

    As for 42 on 2x & 3x, I'm not so sure that the rear derailleur can take up that much difference in chain slack.



    Quote Originally Posted by bikeguru1 View Post
    Gearing talk on MTBR really brings out the egos. If my conversation at Interbike this fall with Chris, the owner of Niner, is of any indication of a common mindset or at the very least a misconception that modern gearing is adequately low enough. I suggested that there should be two sets of direct mount holes - one for "Sea Otter" gearing (26/38 and higher) and one for "Alpine" gearing (22/36 and lower). I am currently running a Middleburn crank with a 58/94 BCD and 20/30/Bash on my 2014 RIP. Behind my Raceface BB cups I have a .7mm spacer driveside and 1.8mm on the non drive. I have a Sram X0 22/36 FD all mated up to XTR shifters and RD and an 11/36 XT cassette. Quite a cluster. My first gear is a bail out and when needed it sure is nice to have it. My top end is spun out at 27 mph - plenty fast for single track. I don't use the 11 or 12 when on the small ring opting to jump to the "big" ring and I have no rubbing or extra wear on the 30/36 combo that I about live in while the "Sea Otter" guys are bailing to their "small" rings and my momentum carries on. It made sense to Chris when explained that way but then he exclaimed his liking of the 1x and the demise of the FD and left shifter all together. Unfortunately the new XO 1x BCD only allows a 30 tooth and the XX1's 28 tooth is still higher than my set up. Even though the plethora of retro 38, 40 and 42 cogs by WTC, Endless and the likes are supposedly for 1x systems they will provide for many riders running 2x and even 3x (gasp!) and who have longed for lower gearing out back - even if they are running "Sea Otter" dhainrings. Just like Nino and Julian. Sorry for the thread jack, just coudn't help myself. Flame on! Where is Bruce Brown when you need him? Lets get Muzzinac in here too!
    I have a 6 Berth & 2 Berth Motorhomes that I rent out . They are based in Tauranga, New Zealand

Similar Threads

  1. Zeus frame design flaw?
    By nhodge in forum Ventana
    Replies: 104
    Last Post: 01-31-2014, 11:34 AM
  2. SRAM X.9 Rear Derailleur has got a rather annoying design flaw!
    By kapusta in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 81
    Last Post: 09-15-2013, 06:16 AM
  3. W.T.Hel..........! possible design flaw in RIP RDO
    By AZmtncycler in forum Niner Bikes
    Replies: 7
    Last Post: 09-14-2013, 04:22 PM
  4. Replies: 10
    Last Post: 03-19-2012, 04:50 AM
  5. SPECIALIZED ENDURO warranty design flaw
    By 2biker in forum Specialized
    Replies: 32
    Last Post: 02-23-2012, 07:05 AM

Members who have read this thread: 0

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.