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  1. #1
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    Rize Seatstay Pivot/Bearing Design

    I have put about 800 miles on my Rize 4 over the course of 8 months and have gone through 2 sets of bearings on the linkage/shock end of the seatstay and boogered up 2 bolts. As mentioned in other threads this appears to be a very weak design and some go as far as to call it a design flaw. See this thread Look what I found! (Rize rear suspension creak elated). I am inclined to agree.

    The upper attachment of the linkage arm to the frame uses a through bolt while the attachment of the linkage to the seatstay uses 2 separate bolts threaded into the linkage. This attachment of the linkage to the seatstay seems to be a constant problem area. Can someone tell me why they did not use the through bolt for the seatstay attachment?

    I am thinking of drilling out the threaded portion of the linkage and using a through bolt identical to the upper linkage attachment as this seems like a lot better method of attaching the seatstay then the two seperate bolts. It seems that the through bolt would increase the stiffness and also the service life of the bearings.

    Have other had problems with this area? Let me know what you think about changing the 2 bolt system to a through bolt.
    Last edited by tgoff; 09-03-2010 at 02:51 PM.

  2. #2
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    If you tighten the bolts beyond the 5Nm you are putting too much pressure on the sides of the bearings and crushing them. This in turn will also start to push the bolts out.
    The 2 bolts work fine for me, just make sure that you use a bit of the blue loctite on the threads so they don't back out.
    I don't know of anyone who has put a through-bolt. Hope this helps.
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  3. #3
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    Quote Originally Posted by chaphob
    If you tighten the bolts beyond the 5Nm you are putting too much pressure on the sides of the bearings and crushing them. This in turn will also start to push the bolts out.
    The 2 bolts work fine for me, just make sure that you use a bit of the blue loctite on the threads so they don't back out.
    I don't know of anyone who has put a through-bolt. Hope this helps.
    I torque them to spec with a torque wrench and always use loctite. I can ride smooth trails all day long and week after week and I have no problems. As soon as I ride trails like Downieville, Alpine, Annadel, and other similar fast rough/rocky demanding trails I seem to almost always have problems after the ride with only one of those 2 bearings. I have no problems with the other 4 bearings or the main pivot bearing.

    The problem area is the only one where the pivot linkage has bolts in single shear and I think that this is why I only have problems with these bearings. A through bolt like the other one in the linkage would be in double shear. This would allow for less defection than the existing one bolt and would put less demand on the bearing.

    I just now replaced those bearings again and assembled it back to factory specifications. I think if I have another problem I may experiment with the through bolt.

  4. #4
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    I'm going to revive this old post and confirm, that this is indeed the weakest part of the rear suspension. Bad thing is, you can't order those bolts separately, they come only as part of the KP072 kit selling for $40. I've already gone through two bolts, and now third is failing. It still holds, but yesterday it loosened and developed a creak. Part of the threading is gone, and bering seal is crushed and in fact is open right now. If you guys know, where to get good supply of Cannondale Part # 121832 (pivot bolt) please let me know!
    Thank you.
    "Flow" is characteristic of the rider, not of the trail.

  5. #5
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    Quote Originally Posted by arcticrobot View Post
    I've already gone through two bolts, and now third is failing. Part of the threading is gone, and bering seal is crushed and in fact is open right now. If you guys know, where to get good supply of Cannondale Part # 121832 (pivot bolt) please let me know!
    Thank you.
    Interesting. Do you think the pivot bolt is just too weak for the application? If so, perhaps a steel or Ti replacement might do the trick.
    '95 M2 StumpJumper FS
    '11 Cannondale RZ 120-two

  6. #6
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    Its the bearings.

    The balls flatten/ovalize and create play betwwen the inner race and the balls - this causes the bolt flange to jam/grind into the seatstay upon suspension compression.

    Upgrade the bearings and avoid big hits w/ pro-pedal engaged.
    '95 M2 StumpJumper FS
    '11 Cannondale RZ 120-two

  7. #7
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    I am also on my 4th set of bearing and my 2nd set of bolts. I've just installed the enduro MAX bearing, which are said to be better for compression loads rather than rotation. Hopefully these will last a little longer. It just seems that this is an area that requires regular maintenance rather than once a year.
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  8. #8
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    Quote Originally Posted by Buzzaro View Post
    I am also on my 4th set of bearing and my 2nd set of bolts. I've just installed the enduro MAX bearing, which are said to be better for compression loads rather than rotation. Hopefully these will last a little longer. It just seems that this is an area that requires regular maintenance rather than once a year.
    Yeah, the design places those upper seatstay bearings in constant and extreme compression with little rotation. Only a few of the ball bearings end up bearing the majority of the compression load (the 2-3 balls on the trailing side of the bearing).

    The Enduro Max should be better if for no other reason than simply because they have more balls spaced closer together to bear the load. The Enduro Max are said to last a year, which if true, is good enough for me.

    Im no engineer, but it seems pretty obvious that a totally different type/size of bearing should have been used by C'dale at that upper seatstay pivot. The fact that they never addressed/upgraded these pivots for the entire Rize/RZ model run does not speak very well of C'dale.

    Wouldn't a balljoint or spherical bearing work in that upper seatstay pivot application? I know they work well in an automotive sway bar/ suspension link type of application, which sees MUCH higher compression loads.
    Last edited by Stumpjumpy; 04-23-2012 at 07:02 AM.
    '95 M2 StumpJumper FS
    '11 Cannondale RZ 120-two

  9. #9
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    I got my Rize 3 in July, 2011 (9 months ago) and I'm going to be installing at least the six new Enduro MAX seatstay and link bearings this week too. I'm pretty sure that the twisting/torqueing of my rear assembly is ample indication of play in at least these bearings. I will check for play after and decide if the pivot bearings need to be replaced as well. Hopefully, I won't need any new bolts, 'cause I didn't get any. The bolts are snug though, so I am relatively certain that they are OK.

  10. #10
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    Quote Originally Posted by DRSpalding View Post
    I got my Rize 3 in July, 2011 (9 months ago) and I'm going to be installing at least the six new Enduro MAX seatstay and link bearings this week too. I'm pretty sure that the twisting/torqueing of my rear assembly is ample indication of play in at least these bearings. I will check for play after and decide if the pivot bearings need to be replaced as well. Hopefully, I won't need any new bolts, 'cause I didn't get any. The bolts are snug though, so I am relatively certain that they are OK.
    I just set the bike on the ground, grab it by the seatpost an slowly lift the back wheel up. You can feel very slight play this way and figure out where the offending pivot is.
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  11. #11
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    What are other manufacturers using at the pivots in terms of bearings, bushings?

    Ball bearings are not the way to address suspension pivots: igusŪ Polymer bearings in mountain bikes
    Somebody needs to devise a retrofit kit that employs Igus bearings/bushings!
    Last edited by Stumpjumpy; 04-23-2012 at 11:09 AM.
    '95 M2 StumpJumper FS
    '11 Cannondale RZ 120-two

  12. #12
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    Quote Originally Posted by Buzzaro View Post
    I just set the bike on the ground, grab it by the seatpost an slowly lift the back wheel up. You can feel very slight play this way and figure out where the offending pivot is.
    most likely its a play in the lower shock bushings. it is the fastest wearing component of Rize suspension from my expirience.

  13. #13
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    Quote Originally Posted by arcticrobot View Post
    If you guys know, where to get good supply of Cannondale Part # 121832 (pivot bolt) please let me know!
    Thank you.
    Can't any c'dale dealer special order that for you?
    EDIT:
    I just called Infinity/C/Dale Experts and their system did not recognize that PN.
    Last edited by Stumpjumpy; 04-23-2012 at 03:11 PM.
    '95 M2 StumpJumper FS
    '11 Cannondale RZ 120-two

  14. #14
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    My enduro max bearings have been holding for over a year and I ride like an animal. They are way better than stock.

    make sure to use loctite 638 when installing new ones.

  15. #15
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    Quote Originally Posted by avbcon12 View Post
    My enduro max bearings have been holding for over a year and I ride like an animal. They are way better than stock.

    make sure to use loctite 638 when installing new ones.
    Nice! What is your body weight?

    Also, when "glueing" in the new bearings, do you guys use anything to keep the bearings firmly seated while the 638 cures?
    '95 M2 StumpJumper FS
    '11 Cannondale RZ 120-two

  16. #16
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    Quote Originally Posted by Stumpjumpy View Post
    Nice! What is your body weight?

    Also, when "glueing" in the new bearings, do you guys use anything to keep the bearings firmly seated while the 638 cures?
    Light.. 145/150 plus gear.

    you dont use a ton of 638, just enough to coat them so there should be no need to take measures for any drips/ runs. The only thing I have done (with mine and the others I work on) is use a rubber band around the stays/ bearings to keep them in place.

    Word of caution, the upper pivots in the seat stays and the upper pivots on the link can seem to be 'loose' or too large for the bearings (not exactly a press fit). this is where the 638 shines. once cured (over 24 hours) it will hold them in place and hardens to get rid of any 'slack'

  17. #17
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    Quote Originally Posted by alex_k View Post
    most likely its a play in the lower shock bushings. it is the fastest wearing component of Rize suspension from my expirience.
    Yeah the DU bushings wear out quite frequently and are often the source of any slight "clunking"
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  18. #18
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    Quote Originally Posted by Stumpjumpy View Post
    What are other manufacturers using at the pivots in terms of bearings, bushings?

    Ball bearings are not the way to address suspension pivots: igusŪ Polymer bearings in mountain bikes
    Somebody needs to devise a retrofit kit that employs Igus bearings/bushings!
    My buddy has a blur XC. It's got a similar shock linkage to the rize and it uses a through bolt type axle at that location. Seems that with a through axle like that, even when the bearings fail there's no catastrophic failure of any hardware. You just replace the bearings and be on your way. No frog link gets the mounting threads ruined, and no bolt that only comes in a $40 kit gets ruined either.
    All out of S**** and down to my last F***

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