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  1. #1
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    Chain Contacting Front Derailluer

    I have a 2012 Mach 429 with a XT crank and SLX front D. While in the small ring I can put enough power through so that the chain contacts the derailluer, HARD! I've managed to adjust this as best I can and now it only does it when the chain is below the third cog down, but it still does it. I like to climb in the small ring and 3-5 cogs down for most steeper climbs and keep the cadence high (70+), but when it dips below that get major contact and have to downshift.

    Has anyone else seen this? I thought it was my bike at first, and I rode my friends 2009 and I can get it to do the same thing. My old 2010 didn't seem to have this issue.

    Any ideas would be very helpful. I've replaced the BB, set the torque on all the bolts, replaced the shock bushings, etc. and nothing has cured this problem yet. This is a new frame, so the bearings should all be good and new. I'm at a loss,..

  2. #2
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    Reputation: Hawg's Avatar
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    Have you made adjustments on the FD and through the shifter cable?

    Is the chain hitting the side of the FD cage or the top or the bottom of the FD cage?
    ...and proud member of the anti-sock puppet desolation

  3. #3
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    Oh yes. I've made every possible adjustment to the FD. The contact is coming at the inside part of FD, of course as there's more power put through the crankset the chain comes into contact with the interior (naturally) far right side of the FD. When there's less strain on the crankset the chain sits near the middle innder of the FD. It's like the axle in the crankset is flexing enough to allow this to happen.

  4. #4
    official eMpTyBRain
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    We could go back and forth trying suggestions but I think the easiest/fastest way to resolve this would be to take it to the shop where you bought it or a trusted one.
    ...and proud member of the anti-sock puppet desolation

  5. #5
    Dave
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    you're just a monster mister. I have a 2010 and it does it too.
    I need to ride more and work less.

  6. #6
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    Quote Originally Posted by liteandfast View Post
    you're just a monster mister. I have a 2010 and it does it too.
    No, I can do it on your bike but you don't make your bike do it.

  7. #7
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    I have the same issue on my 5.7 in middle ring (2x setup). Was wondering if it was the bottom bracket "cups" or if it was something in the pivots allowing the components to move incorrectly. I was debating calling Pivot to ask about this issue but stumbled upon this thread.

  8. #8
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    Spaceman -- I haven't spoken to Pivot because this is a new frame, and I checked the torque on all the bolts, etc. I've spoken to them about several other things but not this one problem. I may be selling this frame or bike soon.

  9. #9
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    The 2012 mach 5.7 carbon has an issue with the Shimano FD hitting the chain, it could be the same with the 429. For the 5.7, only a top pull direct mount FD would work.

  10. #10
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    dy3ecs -- Are you saying this would be a different FD than on my 2010 Mach 429?

  11. #11
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    Quote Originally Posted by 29erBob View Post
    dy3ecs -- Are you saying this would be a different FD than on my 2010 Mach 429?
    I am not sure but it might be something you need to look into. My brother is building a Mach 5.7 carbon and he found this thread about the frame needing a specific FD to prevent contact. He said the FD has to be a TOP PULL only.

    Mach 5.7 Carbon Front Derailleur Issue

  12. #12
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    chain rub

    I had a 2010 429 and the chain rub was constant in lower 3 gears. I spent a year trying to get rid of the rub, but no luck. I had several diff. mechanics try. I finally called the factory and they claimed no knowledge of it.

  13. #13
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    I'm looking at the photo's on those threads and that's not where the FD is contacting on the Mach 429. The newer Mach 429 runs normal until you pedal REAL HARD and then something is flexing and the chain is contacting the far outside of (naturally) the inside of the FD. I can't get a picture of it because I'm riding when this is happening and trying to do it on the brakes is hard to hold still. The Mach 429 doesn't pull from the same place as the 5.7c. Maybe the 429c will, but not the alloy frame.

    What I really don't know is if there's some difference in the 2010 and 2012 frames that would require a different FD on the 2012 frame. The shop that did the warranty work on my 2010 frame and rebuilt with the 2012 frame didn't say anything, but then again maybe they don't know.

  14. #14
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    Quote Originally Posted by dy3ecs View Post
    I am not sure but it might be something you need to look into. My brother is building a Mach 5.7 carbon and he found this thread about the frame needing a specific FD to prevent contact. He said the FD has to be a TOP PULL only.

    Mach 5.7 Carbon Front Derailleur Issue
    The Carbon frame uses a different FD than the Alloy frames. The alloy frames use an E-Type with the bracket removed.

    What chain ring are you using and what FD?

    On all alloy Mach series frames and Firebird frames you will use the following Shimano FD's:

    For 10 speed models you need the following
    For Triple cranks you need an FD-M780-E model
    For 26x38 or 28x40 you need FD-M785-E2 model
    You cannot use a 30x42 crank from Shimano unless you then use an SRAM XX S3 type FD with our derailleur adapter pulley. The adapter is not needed on the Mach 4 frame.
    If you have questions call us.
    "The face of a child can say it all, especially the mouth part of the face".
    Jack Handy

  15. #15
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    Quote Originally Posted by dan23 View Post
    The Carbon frame uses a different FD than the Alloy frames. The alloy frames use an E-Type with the bracket removed.

    What chain ring are you using and what FD?

    On all alloy Mach series frames and Firebird frames you will use the following Shimano FD's:

    For 10 speed models you need the following
    For Triple cranks you need an FD-M780-E model
    For 26x38 or 28x40 you need FD-M785-E2 model
    You cannot use a 30x42 crank from Shimano unless you then use an SRAM XX S3 type FD with our derailleur adapter pulley. The adapter is not needed on the Mach 4 frame.
    If you have questions call us.
    Dan -- Did this change from 2010 to the 2012 frame? If I need to replace the FD I will, but I don't want to throw money at the problem needlessly.

  16. #16
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    The only thing that changed is in 2010 it was a 9 speed drive train, and now it's a 10 speed drive train. Of course the frame got some cool upgrades, but as far as fitment of Shimano components nothing changed.

    So if you have a new frame, with a 10 speed parts what I listed above is indeed what you need. If you are trying to mix 10 speed parts with 9 speed parts, then you will have the issues you are complaining about.

    Shimano will always ask you to run 9 speed with 9 speed, and 10 speed with 10 speed, if anything you are doing falls outside what Shimano suggest then you will always have issues in your shifting.
    "The face of a child can say it all, especially the mouth part of the face".
    Jack Handy

  17. #17
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    Dan -- Everything that was on my 2010 frame was transfered to the 2012 frame and then this started happening. I'm not sure what to conclude, but I've personally checked the torque on every single bolt to ensure it's correct, and it is. Any ideas would be very helpful.

  18. #18
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    Have you tried taking out the air on the shock so you could cycle the suspension thru its travel? Maybe without the resistance from the shock you can find what is really wrong with it.

  19. #19
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    Quote Originally Posted by 29erBob View Post
    Dan -- Everything that was on my 2010 frame was transfered to the 2012 frame and then this started happening. I'm not sure what to conclude, but I've personally checked the torque on every single bolt to ensure it's correct, and it is. Any ideas would be very helpful.
    Bob, at this point I would suggest you take it to your local PIVOT dealer to have them check it out. My first guess is that you have parts that have worn out - Chain, Cassette comes to mind. If you are rocking 2 to 3 year old parts, chances are they are just worn out and it's time to replace them. Check the play in your RD as well - it's not uncommon for the points, pins at the link joints in your RD to wear out and for it to become sloppy. It also may be something as simple as the RD pulley wheels worn out.

    Check that out and let us know, as your situation is out of the ordinary.
    "The face of a child can say it all, especially the mouth part of the face".
    Jack Handy

  20. #20
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    Quote Originally Posted by dan23 View Post
    Bob, at this point I would suggest you take it to your local PIVOT dealer to have them check it out. My first guess is that you have parts that have worn out - Chain, Cassette comes to mind. If you are rocking 2 to 3 year old parts, chances are they are just worn out and it's time to replace them. Check the play in your RD as well - it's not uncommon for the points, pins at the link joints in your RD to wear out and for it to become sloppy. It also may be something as simple as the RD pulley wheels worn out.

    Check that out and let us know, as your situation is out of the ordinary.
    Worn parts is something I've considered but w/o finding the silver bullet throwing money at it isn't an option. I'm concerned that the crankset is done and starting to flex under heavy power. Light guys would never see this, but I'm 250 lbs and climb with the little/light guys, so maybe I've caused some metal fatigue in the cranks. That's the closest place to the FD and it's contacting from there before the chain passes through the FD.

  21. #21
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    I found a pretty good deal on a SLX crankset, 10 speed cassett, new chain and RD complete with shifters. It should all be here today. First thing I'll do is swap parts and see what changes. If this doesn't make a difference then I'll be contacting PIVOT to see where to take this bike.

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