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  1. #1
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    Front Chainring granny gear blues...

    What is happening is my chain is stripping off the front chainrings on middle (about once a ride) and when climbing a technical climb it is a guarantee it will do this and I walk the climb...
    I am about to go nuts over this because I have invested thousands on this bike and I cannot ride it.

    I used to have a Proflex 955 a few years ago and never had this issue even under the most extreme short steep technical climbs. Even when the rear suspension tightened the chain while it was working and flexing.

    I am convinced it only does this when I put a high amount of pedaling force down and the rear suspension hits a rock or root while climbing and I get this horrible grinding of the chain as it lifts up and over the teeth of the front chainring.
    Here is what I have done to try to stop this.
    First went from a Dura Ace chain to a SRAM top of the line chain and had it shortened a little. My shop also removed the spacers on the drive side and moved them over to the non drive side as instructed by Specialized in an email.
    We also checked front derailleur limiting adjustments and cable housing length.
    (This has been a 5 month problem and 5 visits to the shop, Bicycles INC Keller Texas)

    Ok, well maybe it is my Hollotech XTR chainrings so I bought a spanking new set of outboard bearing XT cranks and rings and had the chain line double checked again.
    Went for the first ride and it does Exactly the same thing.

    I really think there is something going on when the suspension works under high force climbing that causes the upper chain to become slack and rolls off the chainring teeth thus stripping.

    I am wondering if this frame design is not right for me.
    I am an accomplished rider but I weigh 225 lbs and it is an extra large frame size.

    After all this $$$$ and hours and hours of sop time we are not at a solution.
    Any more help would be a godsend. I would have to have to sell this bike as I love its geometry and smart shock.
    I was told to try a Turner Burner or a SantaCruz but I really like this bike and am willing to fight to keep it however I cant walk all my climbs.

    I was told it might be that my chain tension spring on my XTR rear derailleur might not be strong enough for me.
    I ordered a SRAM .9 with shifters hoping this will do the trick.
    Any help would be welcome.

  2. #2
    smw
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    Quote Originally Posted by ghogman
    What is happening is my chain is stripping off the front chainrings on middle (about once a ride) and when climbing a technical climb it is a guarantee it will do this and I walk the climb...
    I am about to go nuts over this because I have invested thousands on this bike and I cannot ride it.

    I used to have a Proflex 955 a few years ago and never had this issue even under the most extreme short steep technical climbs. Even when the rear suspension tightened the chain while it was working and flexing.

    I am convinced it only does this when I put a high amount of pedaling force down and the rear suspension hits a rock or root while climbing and I get this horrible grinding of the chain as it lifts up and over the teeth of the front chainring.
    Here is what I have done to try to stop this.
    First went from a Dura Ace chain to a SRAM top of the line chain and had it shortened a little. My shop also removed the spacers on the drive side and moved them over to the non drive side as instructed by Specialized in an email.
    We also checked front derailleur limiting adjustments and cable housing length.
    (This has been a 5 month problem and 5 visits to the shop, Bicycles INC Keller Texas)

    Ok, well maybe it is my Hollotech XTR chainrings so I bought a spanking new set of outboard bearing XT cranks and rings and had the chain line double checked again.
    Went for the first ride and it does Exactly the same thing.

    I really think there is something going on when the suspension works under high force climbing that causes the upper chain to become slack and rolls off the chainring teeth thus stripping.

    I am wondering if this frame design is not right for me.
    I am an accomplished rider but I weigh 225 lbs and it is an extra large frame size.

    After all this $$$$ and hours and hours of sop time we are not at a solution.
    Any more help would be a godsend. I would have to have to sell this bike as I love its geometry and smart shock.
    I was told to try a Turner Burner or a SantaCruz but I really like this bike and am willing to fight to keep it however I cant walk all my climbs.

    I was told it might be that my chain tension spring on my XTR rear derailleur might not be strong enough for me.
    I ordered a SRAM .9 with shifters hoping this will do the trick.
    Any help would be welcome.

    Im assuming you are riding a Specialized.? In my opinion a good shop should be able to fix the problem without having to replace all your parts. Unfortunately Im along ways from you and have no recomendationsof where to take it. Perhaps call a few shops, explain the problem, and take it to the one that seems confidence they can fix the problem.

    Sean
    Gears and suspension are for girls and old men. Feel free to quote me in your signature. - Fast Eddy

  3. #3
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    I might put it on chain line or the rear wheel dish and the drop out alignment. They are easy to check.

    The drop outs can be checked by using a dropout alignment tool. MOST shops have one but not all ever think to use them. if they are out a bit it is possible that the torque loads are causing the chein to hit at an odd angle causing your skipping problem. I have seen new frames out of the box like this. It can be small enough to not see, under load is when it will show itself. Here is the tool http://www.parktool.com/products/det...=49&item=FFG-1


    The chain line is simple, put it in the easiest gear (small front and big rear) and stand behind the bike and ensure that it looks right, you can play with the chain line using spacers in the rear hub and bottom bracket. This is usually not a problem but you never know.

    Rear wheel should be checked for correct dish AND centering in the bike. The wheel dish helps the torque loads go through the center and limits the stresses the bike has on the twisting of the frame. Also if the wheel is not centered you can create problems.

    These are all really cost free solutions or very cheap. Some bikes have problems, I know even some top end ones that have weird ones (ghost shifting is a big one in Ti bikes, the Ibis Bow Ti was bad the first year they were out).

    If you are stuck email or post a good quality pic I can look at and zoom in. It might help, sounds weird but some times you can just spot things. I was a bike shop mechanic and a race mechanic, and have seen it all.

    Keep me up to date.

    Chris
    Yes its retro but IT WORKS!

    8 Speed is great and V-Brakes rock!

    Ex-wrench...have a Question just ask!

  4. #4
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    Quote Originally Posted by KINBOY
    I might put it on chain line or the rear wheel dish and the drop out alignment. They are easy to check.

    The drop outs can be checked by using a dropout alignment tool. MOST shops have one but not all ever think to use them. if they are out a bit it is possible that the torque loads are causing the chein to hit at an odd angle causing your skipping problem. I have seen new frames out of the box like this. It can be small enough to not see, under load is when it will show itself. Here is the tool http://www.parktool.com/products/det...=49&item=FFG-1


    The chain line is simple, put it in the easiest gear (small front and big rear) and stand behind the bike and ensure that it looks right, you can play with the chain line using spacers in the rear hub and bottom bracket. This is usually not a problem but you never know.

    Rear wheel should be checked for correct dish AND centering in the bike. The wheel dish helps the torque loads go through the center and limits the stresses the bike has on the twisting of the frame. Also if the wheel is not centered you can create problems.

    These are all really cost free solutions or very cheap. Some bikes have problems, I know even some top end ones that have weird ones (ghost shifting is a big one in Ti bikes, the Ibis Bow Ti was bad the first year they were out).

    If you are stuck email or post a good quality pic I can look at and zoom in. It might help, sounds weird but some times you can just spot things. I was a bike shop mechanic and a race mechanic, and have seen it all.

    Keep me up to date.

    Chris

    Thanks man! Well, a lot of that as been done but you never know. I can post some pics in a bit of my chain line and rear triangle.
    This happens most when I am pushing hard on a climb and hit something compressing the rear suspension. The chain stripping happens only on the front and not the rear.
    Granny is horrible and the mid ring even gets it from time to time.

  5. #5
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    Quote Originally Posted by ghogman
    I was told it might be that my chain tension spring on my XTR rear derailleur might not be strong enough for me.
    How old is your rear derailleur?

    I'm guessing that the chain tension spring is worn so that it isn't keeping enough tension.
    On my Bullit, before I put on a chain guide I use to replace the rear derailleur about twice a year. The return spring would get weak which would cause the chain to drop.

    I'd guess that a frame design that has a lot of apparent chain stay length growth as it goes through the travel would be worse than a design that doesn't. (You don't mention what frame you are riding.)

  6. #6
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    Its a 2004 Specialized Epic Comp disk. Extra Large Frame.
    Rear D. is a couple years old but it only has been ridden on about 5 times. XTR.

  7. #7
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    Sounds like rear derailleur is new enough then.

    Maybe ask on the Specialized board?

    Maybe it is an issue with the XL frame flexing under the power of the climb causing chain to downshift?

    (I included a pic of the stock bike to take a look at the front derailleur cable routing to see if it was attached to something that moved as the suspension went through the travel.)


  8. #8
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    By the sounds of it you are at the point where it has to be a design flaw, check the forum is a great suggestion, if its common I would think you have the problem
    Yes its retro but IT WORKS!

    8 Speed is great and V-Brakes rock!

    Ex-wrench...have a Question just ask!

  9. #9
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    That's the bike, same color too!

    I have sent Specialized emails but no one ever would get back to me.

    I think I tried the forum also and the thread died. I got frustrated a while over this and took a break.
    I can try there again but the company has a "it can't possibly be our design that is flawed" attitude. You have to learn how to try to make what you have work or just get a different brand that does.

  10. #10
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    Got this from a review on the 05 epic s works but could apply to you too
    "The epics bottom run cables (for the derailliers) are a maintenance nightmare. Shifting problems occur if you (or your shop) run the cable housings and cables too short. The epic needs a good sized loop of housing below the bottom bracket so the cables don't bind(or produce ghost shifting) when the suspension is bottomed. the bottom run cables also require more attention after riding in extreme conditions"
    www.mbaction.com

    they also state that a sram drivetrain is less finicky for the bottom run cables

    of course, all the tweaking done by the lbs will prob. have to be undone and the cables applied properly

  11. #11
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    The SRAM set should be here on Monday, I will have them with the .9 put on and mention the cables on the bottom run.
    Also the granny chain line. Hope all this does the trick, thanks for the great replies.

  12. #12
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    In all of this I don't see where you have included the rear cogset in the equation....is it worn? How you can tell if it's slippage on the front or the rear? You're sure your freehub is not the culprit?
    "...the people get the government they deserve..."
    suum quique

  13. #13
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    Quote Originally Posted by Bikinfoolferlife
    In all of this I don't see where you have included the rear cogset in the equation....is it worn? How you can tell if it's slippage on the front or the rear? You're sure your freehub is not the culprit?
    Positive, every thing is new on this bike.
    I have ridden since 93 and am pretty sure its all in the front.
    The rear has not only shifted well, it has been very solid. The chain is jumping over the teeth on the Third front ring all the time and a few times on the middle ring.
    On big ring its never an issue.
    I just had a Chris King rear hub on and it has about 5 rides on it. Rock solid there.

  14. #14
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    Would you be willing to try something - remove your rear shock and then cycle your rear suspension through its full range of travel. While you are doing this, I'll bet that your rear derailleur moves in and out. If it does, it will jump your chain on the crankset under rear compression, and is caused by a too short cable housing under the bottom bracket.

    I had the exact same problem on my wife's Diamondback, and I just couldn't figure it out until I tried the test above. Why this seemed to make the chain skip in the front sprockets rather than the rear set is what still baffles me, but that is exactly what was happening on the Diamondback. A new cable housing 3/8 inch longer under the BB completely eliminated the problem, and saved by marriage!

  15. #15
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    Now that you mention it I recall reading about a similar issue on a Specialized bike a couple of weeks ago.

    Here it is:
    Stumpy Fsr Cable Housing / Shifting Problems?????

    Here are some related threads:
    Stumpy ghost shifting please help!!!!
    full-length housing for R. Der.cable
    Epic ghost exorcised
    Full length rear derailleur housing on epic
    Not Happy about Specialized Choice of Cable Routing
    Ghost shifting on an Epic

    Lots of threads on the Specialized board about how critical the cable housing length is with the cable routing on these frames.

  16. #16
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    Oh man I love a community that gives a hoot.
    I hope this saves my sanity! (might be bad for the marriage )

  17. #17
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    Ok, I got the Sram .9s and rear d. on and had the under the bottom bracket cable housing replaced with one that is 3/4 inch longer to make room for the flex of the suspension.

    I had them re-check the chain line and the rear hanger alignment. I have not had a chance to get it on the trail but as soon as I do it will be a very tense moment.
    If I start up a hill and that sonafa***** starts stripping and dabs my climb, I will go APESHAT!

    That is all. Thanks for the help, interesting post to come soon

  18. #18
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    Well, this problem never went away. Nothing worked.
    Bike is at Richardson Bike Mart Frisco being looked at by a Specialized rep.
    All alignment perfect and has everyone stumped. (No pun intended).

    Wow what a mental beating this has been.

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