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  1. #1
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    650b shock bottom-out shim for seat tube clearance

    Hey! Hoping this helps someone convert a 26" full suspender bike to 650b like it did for me!


    Shock bottom travel reduction instructions

    Purpose: To prevent tire contact with the seat tube at bottom-out travel.

    Background: This simple bottom travel limit shim or washer method has been working flawlessly on my bike for over 2 years. I converted my 26” wheel, 5.5 inch travel full suspension bike to 650b (27.5”) wheels with larger volume 2.3 size tires. But on the first ride of this experimental conversion to a larger wheel than the bike was designed for I discovered that the tire rubbed lightly on the backside of the seat tube when landing moderate jumps. In earlier years with 26” oversize tires on the same bike I was startled by a loud buzz from the tire rubbing the front derailleur cable that is stretched down the backside of the seat tube.

    How do to it: The shims are easily made with thin flat plastic material, such as plastic water bottle material. Thin aluminum, such as cut from a soda-can could also be used. I used a 1/32” acrylic sheet bought from a plastic material supply store called Tap Plastics, http://www.tapplastics.com/shop/product.php?pid=258& . This acrylic sheet can be easily cut and shaped with ordinary paper cutting scissors.

    Simply cut a round piece out of the acrylic sheet with scissors and then cut diagonally inwards towards the center to cut out a hole that would clear the shock shaft. (See photo below.) The diagonal cut in the side of the shim or flat washer allows the shim to be added to the shock shaft without disassembling the shock other than deflating and unscrewing the air sleeve to gain access to the bottom end of the shock shaft. The plastic shim is stiff enough that it remains secure and does not come loose off the shaft while riding.

    Air Shocks: To add one or more shims inside a Fox Float type shocks, such as the RP23 or Float-R, the bottom travel bumper location is easily accessed, by deflating the air pressure and unscrewing the air sleeve by hand and sliding the sleeve away revealing the shaft and small bottom bumper o-ring. This sleeve removal procedure is normally done during the periodic air sleeve oil maintenance recommended every 10 to 40 hours use by Fox. (See Fox service instruction link and graphic below.) The hand loosening of the air sleeve should be done while the shock is mounted on the bike for greatest ease; or if off the bike, a mechanical lever such as a long screwdriver through the shock mount bushing hole or a vise clamping the mount will provide sufficient leverage. This all can be done without removing the shock from the bike in most cases, even to do the periodic oil service.

    The Fox Float bottom travel reduction shim size requires a center hole for the shaft about 3/8 inch or 10mm, the outer diameter overall is 1.5 inch or 38mm. A rough cut is fine; a tightly precise fit is not required.

    Install the bottom limit shim(s) under the wide flat metal washer found inside the Float shocks, on the near mount side of that large washer. After installing the bottom limiting shim(s) wipe some light lube on the seal at the threaded area and screw the sleeve on hand tight again.

    Before airing up an air shock, compress the shock to full bottom travel with the shim(s) in place to see if the tire clears the seat tube. Add as many shims as needed (I needed 2 shims) until the tire clears safely.

    Other brand air shocks may have similar access to the shock shaft.

    Coil Shocks: Coil shocks are also very easy to limit travel. The coil shock must be removed from the bike and the spring removed. With spring removed install the travel limit shim(s) between the rubber bottom bumper and spring perch. After testing the bottom travel tire clearance with shock mounted on the bike without the spring installed but with shim(s) and perch installed, reinstall the spring, perch, and shock onto the bike.

    Forks: Fork bottom travel can be shortened with similar method while lower legs are removed for oil service, using thin plastic shims to limit bottom travel.

    Fox air shock service instruction links:

    http://www.foxracingshox.com/fox_tec...aintenance.htm

    http://www.foxracingshox.com/fox_tec...rvice_Interval

    Related note: If having harsh bottom out problems with Float shocks, regardless of shimming to limited travel, a very nice method to increase rate by limiting volume without limiting bottom travel range was developed by DGC, a pro bike mechanic in South Lake Tahoe. And this method may work the same for other air shock. Here's a link to his technique:
    Shim survey please..........
    Attached Thumbnails Attached Thumbnails 650b shock bottom-out shim for seat tube clearance-650b_shim_floatdrawing.jpg  

    650b shock bottom-out shim for seat tube clearance-650b_shim.jpg  

    Last edited by derby; 06-09-2010 at 06:38 PM. Reason: better title?

  2. #2
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    You can also purchase nylon washer from your local hardware store. They come in assorted thicknesses / internal hole diameters. The washers are just flexible enough to twist past the shock shaft w/ a single slit. Once in place they look almost factory.

  3. #3
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    Quote Originally Posted by keen
    You can also purchase nylon washer from your local hardware store. They come in assorted thicknesses / internal hole diameters. The washers are just flexible enough to twist past the shock shaft w/ a single slit. Once in place they look almost factory.
    Yes, my home made method is ugly. But I used it to show how easy it can be done. And in either case the shims are not visible when a shock or fork is reassembled.

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    Thanks for the info. I just did this on a DT Swiss XM180 to shorten the stroke on a Mojo SL and will add shims for a 650b conversion. Here are some pics of nylon washers cut, a Fox 10mm fork shim(clips on), how it looks on the shock and rear wheel clearance.
    Attached Thumbnails Attached Thumbnails 650b shock bottom-out shim for seat tube clearance-img_2619.jpg  

    650b shock bottom-out shim for seat tube clearance-img_2620.jpg  

    650b shock bottom-out shim for seat tube clearance-img_2622.jpg  

    650b shock bottom-out shim for seat tube clearance-img_2625.jpg  


  5. #5
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    Quote Originally Posted by lml427
    Thanks for the info. I just did this on a DT Swiss XM180 to shorten the stroke on a Mojo SL and will add shims for a 650b conversion. Here are some pics of nylon washers cut, a Fox 10mm fork shim(clips on), how it looks on the shock and rear wheel clearance.
    Much cleaner looking. Thanks for posting pics.

    Many suspension bikes would need much less shim thickness for 650b tires to clear the seat tube at bottom travel. Generally, for most suspension bikes there is about 2.5 times rear wheel travel to shock shaft travel. Forks of course are 1:1 travel with the wheel.

    The shims also reduce air volume and the deep travel air spring ramp-up progression is increased proportionately to the reduced travel if the shim is as wide as the inner diameter of the chamber.

    If having harsh bottom out problems with Float shocks, regardless of shimming to limited travel, a very nice method to increase rate by limiting volume without limiting bottom travel range was developed by DGC, a pro bike mechanic in South Lake Tahoe. And this method may work the same for other air shock. Here's a link to his technique:
    Shim survey please..........

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    Thanks for the additional info. I keep learning alot from this forum and greatly appreciate it. Here is what I am trying now. I have both a DT Swiss XM 180 (55mm stroke) and a Fox RP23
    (50mm stroke) Pushed for my Mojo SL. Both strokes need to be shortened for 650B and the DT for both 650B and 26". The DT is very linear with very little ramp up (may cause harsh bottom out), very plush. My RP23 seems to ramp up very hard with a kind of dead feeling rebound, but can handle very harsh riding. I am 6'4 225 lbs. and I know it is hard on an air shock. Here are pictures of rubber spacers that can either go behind the DT factory bottom out to take up air volume or in as a spacer, which will take up volume and soften bottom out.
    Attached Thumbnails Attached Thumbnails 650b shock bottom-out shim for seat tube clearance-img_2626.jpg  


  7. #7
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    I remember a few years ago I tested a Santa Cruz Superlight with a 650B rear and the only reason it would not work is the wheel hit the seat tube at full compression. This method would make that frame work with 650B and its a perfect candidate for conversion with its low BB and 2:1 shock compression ratio. It gets one thinking! I still have the pics. It fits the rear with a Neo Moto 2.3 tire and the derailleur clears.
    Attached Thumbnails Attached Thumbnails 650b shock bottom-out shim for seat tube clearance-superlight1.jpg  

    650b shock bottom-out shim for seat tube clearance-superlight-compressed1.jpg  


  8. #8
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    Quote Originally Posted by Waterat Pat
    I remember a few years ago I tested a Santa Cruz Superlight with a 650B rear and the only reason it would not work is the wheel hit the seat tube at full compression.
    A Superlight would be a great conversion to 650b. Low BB, efficient climber, and the moderately steep frame geometry would be more relaxed in handling and feel for enduro trail riding with 650b.

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    Great info......just doing this now on RFX conversion...

    I'm limiting travel for my RFX conversion (thanks Keen for all your help). Couldn't readily find a used RP23 X 1.75 so got myself a X 2.0 and have tried one rubber washer thin shim but its not enough. So soon I'll open it up again to add a thicker one or add a elastomer left over from my PRS saddle. Its the hardess one they make for the PRS system, and its 10mm thick. I thought it could work because it'll compress at the end of the stroke. If I find its too thick, I'll just get out my belt sander and take a couple mm's off at a time. Any comments if this is a good idea or not? Or should I stay with a thick, more rigid dense, rubber washer?
    Thanks

    PS. Also wondering about the real world experience of compressing an air shock all the way. Does this really happen a lot? Perhaps riding style dependent like hucking or extreme AM?
    Anyway, I have a few more months to get advise and play since my 'extreme knee injury' still has me banned from mtb. Good news, is the doc gave me clearance for road 2 days ago, and I did my first ride yesterday and all is good!
    Attached Thumbnails Attached Thumbnails 650b shock bottom-out shim for seat tube clearance-mvc-066s.jpg  

    We told you 650b rocks! Riding converted RFX for years!

  10. #10
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    Excellent! Thanks for starting this thread Derby. I've been loving the 650b front on my Mojo, and just started pondering what I'd need to do to convert the rear.....garage tinkering time is limited these days, so thanks for shedding some light.
    JR

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    Quote Originally Posted by Spongebob
    I'm limiting travel for my RFX conversion (thanks Keen for all your help). Couldn't readily find a used RP23 X 1.75 so got myself a X 2.0 and have tried one rubber washer thin shim but its not enough. So soon I'll open it up again to add a thicker one or add a elastomer left over from my PRS saddle. Its the hardess one they make for the PRS system, and its 10mm thick. I thought it could work because it'll compress at the end of the stroke. If I find its too thick, I'll just get out my belt sander and take a couple mm's off at a time. Any comments if this is a good idea or not? Or should I stay with a thick, more rigid dense, rubber washer?
    Thanks

    PS. Also wondering about the real world experience of compressing an air shock all the way. Does this really happen a lot? Perhaps riding style dependent like hucking or extreme AM?
    Anyway, I have a few more months to get advise and play since my 'extreme knee injury' still has me banned from mtb. Good news, is the doc gave me clearance for road 2 days ago, and I did my first ride yesterday and all is good!
    Go to a hardware store and pick up some nylon washers. They come in a variety of ID / OD's and after slit can be flexed enough to make a perfect fit on a shock shaft.

  12. #12
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    Seems like a Fox (slotted) fork spacer would be perfect. I only seem to find them stock in 10 mm size, but it seems it could be cut in half w/ an hot knife or grinder parting tool or chop saw to get to 5 mm?

  13. #13
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    Or stacking

    Quote Originally Posted by buggymancan
    Seems like a Fox (slotted) fork spacer would be perfect. I only seem to find them stock in 10 mm size, but it seems it could be cut in half w/ an hot knife or grinder parting tool or chop saw to get to 5 mm?
    a number of washers to gain 5mm of thickness. i cut my own and they worked well.

  14. #14
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    Does this mod adjust the eye to eye at all, or does it simply adjust the stroke?

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    The eye to eye does not change. It simply limits the stroke.

  16. #16
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    I ended up stumbling upon some nylon washers at ACE Hardware that are 3.8" ID, which equates to 9.5mm, and about .5mm in thickness....used some wire clippers to snip an angled slot in them, and with the slightly under sized diameter they stay put nicely. I forget now how many I used.... I believe it was 7 or 8...anyway, very clean, simple, and about $1. Light-tuned RP23 already bottomed way too easily at full travel, so added Fox's med. volume adjuster shim for more progression.....and it's money!

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    Bumping this super helpful thread. Thanks, contributors!

    Mike

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    Cool Thread guys, I have done the front of my HD and love it, going to do back now after this advice. Still have first HD frame so any advice. I have a SLR on it's way (when they have stock, another story for another day) and after my results with the test on 650B i would love to build it from the start as FULL 650B - any advice here, has anyone done a SLR?

    ROCKSHOX REVELATION does it fit 650B? I hear the LYRIK does, I need fork for SLR. I want to make my SLR my X-country bike and my HD my play bike, I have a 29er but just find it DULL with that weedy 110mm thin stanchion fork although I have THU-AXLE, the whole setup odd but it does go fast downhill and it does roll nicely. Any advice to keep it light and fun?

  19. #19
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    ROCKSHOX REVELATION does it fit 650B? I hear the LYRIK does, I need fork for SLR. I want to make my SLR my X-country bike and my HD my play bike, I have a 29er but just find it DULL with that weedy 110mm thin stanchion fork although I have THU-AXLE, the whole setup odd but it does go fast downhill and it does roll nicely. Any advice to keep it light and fun?[/QUOTE]

    2009 Revelation fits thats the year they used the Pike lowers which also fits. Both are good choices for a stiffer 650B fork. I run a 20mm Pike.

  20. #20
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    Quote Originally Posted by MOJODAVE View Post
    Cool Thread guys, I have done the front of my HD and love it, going to do back now after this advice. Still have first HD frame so any advice. I have a SLR on it's way (when they have stock, another story for another day) and after my results with the test on 650B i would love to build it from the start as FULL 650B - any advice here, has anyone done a SLR?
    ....
    The original HD140 (without the recently increased seat tube tire bottom out clearance) will clear 650bx2.3 easily with no mods. The HD160, both versions, need to limit bottom travel using shock travel shims (very minimal for the new HD160 with added seat tube clearance).

    The SL-R did NOT clear my 650b wheel in the chain-stay, in one of the first batch displayed at the Sea Otter Classic in April 2011 before they were available retail. Clearance was too short, not event a shorter small race tire would have cleared. I'll try fitting my wheel again this year into a production SL-R, maybe the tire clearance is improved to be as much as the SL (which does clear pretty easily with a minimal shock bottom travel limit shim).

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    Thanks for the info, the frame arrived and I took a wheel with tire, put it in - it fits with about 3-4mm to spare. Let the air out the shock and at complete bottom out it touched the frame. I will take a photo later and post it. Did my HD160 front wheel and just love the feel.

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    Ok not very good with this stuff, got a question via Private message typed a long reply only to be told I have to have made 10 posts before I can do that so if I sound like I am posting crap, I need my 10 posts or have I got this wrong.

    To answer the question - yes the wheel spins with 3-4mm clearance with a Stans Crest Rim and Schwalbe 2.25 rubber hoof. I have not put the cluster or anything on yet need to pick up that today. I will keep posting with progress to get my posts up and to keep you informed.

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    Took some photo's of HD (white) and SL-R (Black/Blue) so you can see the clearance.
    Attached Thumbnails Attached Thumbnails 650b shock bottom-out shim for seat tube clearance-14022012047.jpg  

    650b shock bottom-out shim for seat tube clearance-14022012044.jpg  

    650b shock bottom-out shim for seat tube clearance-14022012049.jpg  


  24. #24
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    Quote Originally Posted by MOJODAVE View Post
    Took some photo's of HD (white) and SL-R (Black/Blue) so you can see the clearance.
    That is GREAT news. Ibis responded to the 650b advantage and increased the clearance of the SL-R swingarm for production.

    I had tried fitting my 650b wheel in one of the first run of a few, maybe 5 early press release SL-R's, which was no where near clearing any 650b tire. Ibis again impresses by quickly responding and correcting a "design defect"

    The Mojo SL and earlier Mojo C also clear 650b with the same space as your SL-R appears to. It's enough for all but sticky leaf days, and sticky leaves or layering mud are just as bad with more tire clearance. Prior to my HD I rode my Mojo C with 650b for 4 years with no problems specific to the larger wheel size. The finish inside the stay yoke near the edge knobs gets worn a little over the years from mud grinding and small rock scrapes, but the tires never rub if the wheels are fairly true.

    Very sorry to hear about the mtbr firewall to be able to reply to a PM. It's unfortunate a very few repeat banned creeps and drunks make it hard for the 99+% of riders new to mtbr discussion wanting to sign up and quickly contribute. The new policy seems to have effectively reduced the frequency of toll posts a lot.

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    Thanks for feedback, maybe that was the delay of the SL-R getting to market. If they made it better then all is forgiven. Shimming my HD tonight and going to give the FULL 650B conversion a whirl tomorrow evening.

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    Thanks for posting up MOJODAVE. That is great news.

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    Anyone shimmed any of the manitou air shocks? Seemed like I had to add a ton of spacers to limit the travel. Post any pictures you might have if you get a chance. Would be greatly appreciated.

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    i shimmed a 7.875 x 2.25 swinger 3way down to 2"ish using the hardware store plastic washers for the back of my fat possum w/ a 2.1 nev .

    i think it was 4-5 washers that are right around 1.5mm , the tire just kissed the cable stop & now has 4-5mm clearance .

    strangely , w/ the original split spv shock it rubbed just a tad more but still not enough to stop the tire , same shock dimensions .

    all of this was w/ all the air removed and my weight on the bike squishing the bottom out bumper , prob would have never been an issue aired up but i wanted to be safe , and sure .

    i just did the dhx5.0 air on another bike , same shock dimensions but 2" stroke, to make room for a 2.3neo , 3 washers . that was only a problem w/ no air/my fat ass also , did not touch w/ a quasi but it was really close .

    is your bottom out bumper in good shape ?

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    Awesome news! Thanks for posting.

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    checked my notes , 3 washers in the swinger and could maybe take 1 out

    2 in the dhx

    3 of these washers stacked up is just about 5mm

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    anyone know the shaft size for RS monarch? Thanks!!

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    I haven't opened my new RT-AM yet, but I recall Daren from Push saying they are 9mm vs Fox's 10mm...IIRC
    A post in the suspension forum will probably yield a more confident answer.

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    Thanks a lot, I will open it and measure tomorrow.

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    Yes I took it apart and measured, it`s really 9mm.

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    Anybody tried shimming a DRCV shock? I would like to go 650B on my Roscoe 3 (2010). We put my buddies TL28 w/2.3 Neo on the back. Deflated, you could get a sheet of paper or two between seat tube & tire. Would say, 10mm of shims give enough clearance in real world riding? Probably about 220# w/gear. 2010 Fox on front sounds like it should work from the reports I have read.....
    Last edited by VTPossum; 03-03-2012 at 05:53 AM.

  36. #36
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    Quote Originally Posted by VTPossum View Post
    Anybody tried shimming a DRCV ? I would like to go 650B on my Roscoe 3 (2010). We put my buddies TL28 w/2.3 Neo on the back. Deflated, you could get a sheet of paper or two between seat tube & tire. Would say, 10mm of shims give enough clearance in real world riding? Probably about 220# w/gear. 2010 Fox on front sounds like it should work from the reports I have read.....
    Best guess is yes... If you deflate the shock and then unscrew the air sleeve and slide it apart (no need to remove the shock from the bike), then look inside to see if the shock's shaft is accessible to put a thin split-washer shim around the shaft.

    The problem might be the duel-rate control valve may interfere with access and clearance for a split-washer around the main shock shaft.

    Picture courtesy of Fox User Guide

    FLOAT RP2, RP23 DRCV
    Attached Images Attached Images  
    Last edited by derby; 03-05-2012 at 08:07 AM.

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    Thank you for the input Derby. I shouldn't cause any issues by carefully backing off the outer sleeve/can is my understanding then. I will give a report when I try it in the next few days. I had seen on the Fox website they do not offer travel reducers for that shock. Hope there is clearance for some shims..
    Like many others, I would love an HD. I have heard nothing but great things about Ibis from my friend, a Mojo C owner. I have seen first hand how they step up to the plate for their customers and beyond. Maybe someday...

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    Can I use this to limit travel on a 2" stroke shock to 1.75", in order to run a common size 2" on my Rush with it's silly 1.75"? I think the answer is yes, just looking for comfort comfirmation.

  39. #39
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    Quote Originally Posted by sandwich View Post
    Can I use this to limit travel on a 2" stroke shock to 1.75", in order to run a common size 2" on my Rush with it's silly 1.75"? I think the answer is yes, just looking for comfort comfirmation.
    Yes. No problem.

    Specialized had such an OEM shock from Fox, with a shaft spacer inside the air can, to reduce stroke from 2.0 to 1.75 for their "Triad" shock on one of the XC full suspension racer bike models for a few years. The Fox designed spacer could not be removed without complete disassemble.

    For an air shock, I'd recommend making the split washer plastic shims as wide as possible to fill the inside diameter of the air can (the Fox Triad shock spacer is near maximum width), so the air volume in the can is decreased in close proportion to the decrease in stroke, producing a soft "bottom bumper" from the rising rate ramp up of compression resistance of an air spring.

    I'm doing this now, limiting more than 1/4 inch shock stroke, using many hand made plastic split washers (such as pictured in the original post) to limit a 8.5x2.5 coil X-Fusion Vector HLR to less than 2.25 stroke on my HD160, and using a #50 firmer coil to avoid hard bottom-out. The limited stroke of my shock is because of two factors: 1. My 650b rear wheel doesn't clear a HD160 without limiting travel (the HD140 clears with no modification of travel); 2. I've added offset shock mount bushings to lower the rear suspension to the height of the HD140, to avoid needing a second shorter travel shock as the HD140 is designed to use with different mounting hardware. The Off set bushings don't limit travel, just moves the range deeper from top to bottom travel, so the rear tire of any size has reduced seat tube clearance.

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    Thanks derby. Which side of the shock do I place the spacers on? The original post is unclear as to whether you put them under the air can eyelet or at the bottom of the air shaft/where the square aluminum spacer is. I would imagine you'd want them where they won't slide over the shaft and are instead stationary, but I just want to make sure.

  41. #41
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    Quote Originally Posted by sandwich View Post
    Thanks derby. Which side of the shock do I place the spacers on? The original post is unclear as to whether you put them under the air can eyelet or at the bottom of the air shaft/where the square aluminum spacer is. I would imagine you'd want them where they won't slide over the shaft and are instead stationary, but I just want to make sure.
    Depends on the air shock design. If a Fox, it's around the shaft at the propedal lever end.

    The shims can be installed loosely apart, and during use or cycling the shock to bottom-travel by hand, will pack into the air sleave end cap and become stationary. Using plastic split-washers, hand made or if you can find something store bought, if they slide a little on the shaft there would be no damage or wear to the metal shaft that would be any more than the damper seal and bushing would do if your later remove the shims.

  42. #42
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    Derby,
    I'm building a mojo 160 650b with a pair of enve 275's. I haven't picked a tire yet, love the nobby nic but it''s not out in 275 until oct-is as ive been told by Brian Mullin at grams light bikes. Suggestions on tires and setup would be much appreciated. Running the 13 fox talas 650b w/ 160mm travel on the front. I ordered the fox spacer kit for the rp23 from jensen will I need it?

    Thanks a bunch

  43. #43
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    P.s. interested in the offset bushing route too, I'm 5'7" with shorter legs on a med hd thanks

  44. #44
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    Quote Originally Posted by deofour View Post
    Derby,
    I'm building a mojo 160 650b with a pair of enve 275's. I haven't picked a tire yet, love the nobby nic but it''s not out in 275 until oct-is as ive been told by Brian Mullin at grams light bikes. Suggestions on tires and setup would be much appreciated. Running the 13 fox talas 650b w/ 160mm travel on the front. I ordered the fox spacer kit for the rp23 from jensen will I need it?

    Thanks a bunch

    P.s. interested in the offset bushing route too, I'm 5'7" with shorter legs on a med hd thanks
    The HD140 requires no shock modification to fit 650b wheels with up to 2.3 size tires. Ibis has sanctioned the HD140 for 650b use.
    Ibis has certified 650b for the Mojo HD140 - Mtbr Forums

    Ibis HAS NOT sanctioned the HD160 for 650b use. 650b wheel will contact the seat tube before bottom out, without custom shock modification.

    The HD 160 with 8.5x2.5 inch shock requires custom shims, as described in this thread, to prevent seat-tube contact by a 650b tire. The Fox kit does nothing to limit travel except ramp up the air spring rate sooner, but a big hit can still bottom the shock shaft travel with the Fox air volume reduction kit.

    Regardless if you use the Fox kit the new late 2011 second generation HD160 having added seat tube clearance for tires, requires 1/8 inch total in custom plastic split-washer shims. The first generation HD160 would need more shims, not sure, probably nearly 1/4 inch thick.

    Always check a shimmed shock travel bottom clearance by deflating the shock and bouncing all your weight on the seat observing the seat tube clearance to the 650b wheel.

    I used offset shock mount bushings to lower the BB 1/4 inch with the HD160 set up. This reduces seat tube clearance, and also requires adding more custom split-washer shims, a total of 1/4 inch of shims, limiting the late 2011 second generation HD160 shock shaft travel to 2.25 inches. The first generation HD160 would probably need 3/8 inch thickness in shims and the HD140 set up would be the only real safe way to run a first generation HD.

    I've used Pacenti Neo-moto 650b x 2.3 tires exclusively for nearly 5 years. An easy rolling tire, with good traction and handling, and OK in mud, and fairly long lasting hard compound. A great all around tire for heavy duty trail riding. Riding at a downhill park is OK on these tires, but taller more spread apart knobs would be much better. I'm looking forward to the Maxxis Ardent or Highroller announced recently for 650b for DH park use.

    I bought these shock mount offset bushings. There are other options if you search google. These were least expensive and are well made. The HD has 40mm and 22mm wide shock mounts, both with 8mm shock mount bolt holes. It took 3 weeks for the two I bought on eBay to arrive from Poland.
    Offset Shock bushings | Mounting Hardware | Mount kit | All frames | Proshox | eBay

  45. #45
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    Thanks Derby
    So it seems like there is two ways to shim one to put spacers on the shaft to physicaly limit the stroke the other to put plastic in the secondary air chamber. Does one work better than the other?

  46. #46
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    Hello,

    great Thread!

    I have a short question.
    I want to reduce the stroke of an RP23.

    Should I put the spacer behind the large silver washer?

    Or better in front of it?

    What does that Big Silver Ring do anyway?


    Sorry for Capital letters, damn Auto-correct keeps correcting me wrong...

    Greetings ZNARF

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    Quote Originally Posted by Znarf View Post
    Hello,

    great Thread!

    I have a short question.
    I want to reduce the stroke of an RP23.

    Should I put the spacer behind the large silver washer?

    Or better in front of it?

    What does that Big Silver Ring do anyway?


    Sorry for Capital letters, damn Auto-correct keeps correcting me wrong...

    Greetings ZNARF
    Probably doesn't matter which side if just adding a thin split washer shim. Maybe easier to add to the "outside", the side easily seen side of that big washer after deflating the shock, unscrewing and sliding the can away to see the area that washer is in.

    I think that washer may be a baffle to keep the oil can's splash oil from getting up to the shrader air valve and pissing out a little each time when attaching an air pump. Not really sure. They didn't have those in earlier years of Float shocks. Otherwise maybe it is to support the Fox air volume reducer kit shims (which do not reduce stroke, but do change the spring's progression rate).

  48. #48
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    I picked up some fiber washers at hd and they installed easily. I am concerned that they may swell but we'll see. Install was easy just twist the can to unscrew. I'm starting with 1/8 inch on my mojo Hd 650b with some tape on potential rub areas to track bottom out.
    Attached Thumbnails Attached Thumbnails 650b shock bottom-out shim for seat tube clearance-image.jpg  


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    Avalanche DHX 5 on Mojo HD 160

    Here is a pic of a shim I put on an Avalanche DHX 5 coiler @ Mojo HD 160. Craig replaces the default bumper with a thick foam one for a better and smoother performance in the last 1/2" of piston travel. I was quite surprised that I could not really make the Nevegal 2.1 rub w/ the spring removed. To be safe though, I added a 1/16" plastic washer that I found in Lowe's. It is a perfect fit for the coiler.


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    Will this work on a dhx air?

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