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  1. #1
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    XTR Crank Arm problem?

    On my last two out goings I have felt some slip or play from my cranks when hammering down on the pedals. I just took it to my LBS for this reason; I picked it up today and the problem persists. My LBS thought it was a loose collar in the cranks but apparently not. Has anyone experience this same problem? This really breaks my concentration on the climbs. Any suggestions?

  2. #2
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    I had something similar once/twice. It took me a long time to find. In the end it was a chainline / chain problem on one occasion and a badly designed rear hub the other time.

    In one case my chain would catch on the next cog momentarily - get lifted up just a bit - and create a sense of slipping in the process. Fixed it by getting a narrower profile chain, didn't have to mess with bb spacers etc. Does this occur on either your 1 and 2 cogs or else your 8 and 9 cogs? That would point to a chainline issue because the chain is most angled for those cog combinations.

    I had another similar problem with a rear hub many years ago: the pawls would engage with way too much lag [I hope pawls is the correct English language word - this is not my mother tongue].

  3. #3
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    I read something that sounds similar to your problem in the drivetrain forum.It was on page two,labeled "major xtr probems".
    milesW

  4. #4
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    XTR cranks okay

    So my LBS was able to figure out the problem, cranks are not to blame but I have a new front triangle en route. The bottom pivot developed some play causing my cranks to make contact with the rear triangle. It should be ready to roll this weekend. Meanwhile I was given a demo to ride!!!! Thanks Cal Coast for the excellent customer service!!!!!!

  5. #5
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    Reputation: Alabama's Avatar
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    I had my third drivetrain service today because of this issue. The drivetrain POPS loud under hard pressure. The LBS is perplexed.

    Gonzo, how do I check for this issue?

  6. #6
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    Have your LBS remove the rear triangle and check for loose pivot points or worn bolts. Be sure they torque everything to spec. I was told by my LBS that some of the first batch of SL's were not inspected as their was a high demand for these frame to be delivered. Use the process of elimination, rear pivots, cranks and rear hub. Good luck Alabama!!!!!

  7. #7
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    Thanks. It seems solid. I truly have had drivetrain issues but have been ashamed to post such a wussy issue. I search the drivetrain forum for the aforementioned link to no avail. The bike came on Christmas Eve after great hast and was built guzzling brew. I'm absolutely positive the bike is not torqued to spec. So, who has a link to torque specs?

  8. #8
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    Not sure if you have xtr hubs or not ,but mine make a noise that sounds like what you are describing .Its been said that the pawls slip Good luck and let us know . Harry.

  9. #9
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    I appreciate no one fabricating a answer to the torque spec question. Apparently that is the correct answer. No torque specs exist. I spoke with a gentlemen at Ibis today and he confirmed that no torque specs have been created for this bike. The Ibis rep stated "you know man, wrist tight, your not going to break it" Good enough!
    I took the bike to my NSLBS (not so local bike shop) to utilize their impeccable road mechanics. One mechanic recreated the pop. So, we simply tore down the drivetrain and rebuilt it. It appears cured. Zero flaws in my bike.
    Gonzo based on the Ibis rapid response, it appears that your issue was an obvious material flaw and had nothing to do with torque settings. Anyway, you must be smitten with the result to your issue. What a top notch company!!! Thanks Gonzo.

  10. #10
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    My bets are on the rear HUB. My wife has a similar problem with her XTR rear HUB. Under pressure the pawls seem not to grab, appears to be only random though and hard to repeat after it has happened. Kind of like the mythical mysterious engine noise when you go to the mechanic only to have it never happen when the mechanic is checking it out. I now have to fix it.

  11. #11
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    Non-compact crank Mojo compatibility?

    Has anyone run a standard 24/34/46 (74/110) crank on a Mojo, other that myself? Seems that the larger 46t chainring tends to rub on the chainstay (plate) as the bike cycles through it's travel? I have tried running a 24/34/44 (110/5 bolt) chainring setup to eliminate the chainstay interference, but cannot seem to get the front deraileur to shift onto the big ring. Seems the current crop of XTR deraileurs requires a 12t min. middle to outer chain ring difference (not 10)? any ideas?
    Last edited by buggymancan; 02-20-2008 at 06:35 PM.

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