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  1. #1
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    New question here. XTR 986 FD compatibility with small Blur TRc

    Cross post from the Santa Cruz forum but I haven't gotten much feedback

    Built a small Blur TRc for my girlfriend and the front derailleur interferes with the chain when it is in the big big(largest 2-3cogs) combination and the suspension compresses

    Setup
    XTR 986 FD compatibility with small Blur TRc-img_20121017_210715.jpg

    View from behind
    XTR 986 FD compatibility with small Blur TRc-img_20121019_150105.jpg

    Suspension compressed
    XTR 986 FD compatibility with small Blur TRc-img_20121019_150247.jpg

    So do you something obvious in my setup? The FD was originally set 2-3mm above the outer chain ring. A friend later suggested a different method of setup and I raised the FD. I'd say it is sitting 5+ mm above the outer chain ring now but the pinch bolt still makes contact.

    Any suggestions?

  2. #2
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    I think an E-type FD will have the fixing bolt on the other side so the cable will fix behind the seat tube, and won't interfere with your chain. For XTR I think this would be a 985-E or something like this:
    http://techdocs.shimano.com/media/te...9830721102.pdf

  3. #3
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    From the santa cruz faq:

    What kind of front derailleur do I need?

    The Blur TRc uses a 34.9mm bottom swing (high clamp), top pull front derailleur. Pretty much anything that fits this description (besides Saint) will work.

  4. #4
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    Quote Originally Posted by mauric6943 View Post
    From the santa cruz faq:

    What kind of front derailleur do I need?

    The Blur TRc uses a 34.9mm bottom swing (high clamp), top pull front derailleur. Pretty much anything that fits this description (besides Saint) will work.
    Whatever the FAQ says your FD is causing a problem and I still believe the FD I linked in my response would work. Why don't you call Santa Cruz and talk to someone in the tech dept? They would be building bikes up every day and should be able to help.

  5. #5
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    K - I don't doubt that it would work. I''m just expecting that there are a few other santa cruz riders around that use the same derailleur and may have dealt with the issue.

    I do plan to put a call into SC too

  6. #6
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    You seem to be using an FD meant for a triple on a double drivetrain.

    A triple specific derailleur expects a 32T chainwheel in the middle position, so the clearance is meant of it. However it now gets 39T, so you get interference.

    To fix this you need to place the deraileur around 1/2 of an inch higher then it is now, so the chain in the middle chainwheel ( 39T in your case ) goes through the cage where it should.

    Alternatively - get a double specific mech.

  7. #7
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    Quote Originally Posted by uzurpator View Post
    You seem to be using an FD meant for a triple on a double drivetrain.
    According to the Shimano tech docs the FD986 is double chainwheel specific, so it is the correct FD for this bike - at first I was thinking maybe there was a better option but after looking through all the shimano docs it doesn't look like there is. I don't know if this is just an issue with that gear combo on a small size frame, or if it's something in the derailleur setup process.

    Quote Originally Posted by mauric6943 View Post
    K - I don't doubt that it would work. I''m just expecting that there are a few other santa cruz riders around that use the same derailleur and may have dealt with the issue.

    I do plan to put a call into SC too
    I'm anxious to hear what SC says. The more I look at it, I think you have the correct FD - the other types are for either triple chainwheel setups, or for different mounting hardware like direct mount.

  8. #8
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    Simular problem with my Blur LTc and XO. I posted above. Seems like should be a setup problem becasue Santa Cruz (on their web site) says I'm using a compatable dereailleur. But I can't figure out a solution.

  9. #9
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    Kristatos: My mistake there. I mixed up the models on shimano website.

    Anyhow - if this is a double specific mech, then things might get interesting.

    I have a suggestion for the OP.

    Set the gear to small-small combo ( 26-11 or whatever else you have there ) and rise the derailleur as much as possible, until it still can take up the chain. Then check if you still have the problem.

    If that does not help, then triple specific mech actually might.

  10. #10
    bog
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    Shimano makes an XTR top swing that is good for 2x10. It is called the M985 and has different cable routing. I have one on my Nomad and it works quite well so I would imagine it works on a TRc.
    SC Tallboy C : Giant TCX SLR : Giant Propel Adv SL DA9070

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