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Thread: Dropping Chains

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    Dropping Chains

    I have an SLR with XTR Shadow+, E13 XCX, and Raceface 34T Single ring up front, and I am constantly dropping my chain, almost 1 once a ride. I have the chain setup to the shortest it can go. Tighten the clutch. The chain doesn't come off from the top, but from the bottom. Doesn't matter what gear I descend in, but most of the time I'm in the 2nd from highest. Even if I were to pick up my bike and drop it, the chain would come off the front ring.
    Anyone else have this issue too?

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    I'm having the same problem. I have tried the xtr shadow + and a zee rear derailleur. It seems like there just isn't enough tension provided by the derailleur when in the highest gears. I also run a 34 single ring but have a home made top chain retention device. When my xtr shadow + was new I had no probs but after about 6-9 months I think there is more slack before the clutch activates and this allows the chain to escape. I'm going to try and make my chain device cover more of the chainring.

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    Same here. Seems like there is more play in the chain than before. In fact, today, I heard the chain slapping my spokes. My XCX chain guide is working for the top, but the bottom is where the chain pops off. I think C guide would help, but I really don't want to put one of those on.

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    Quote Originally Posted by mcgong View Post
    Same here. Seems like there is more play in the chain than before. In fact, today, I heard the chain slapping my spokes. My XCX chain guide is working for the top, but the bottom is where the chain pops off. I think C guide would help, but I really don't want to put one of those on.
    We were discussing this here today and though we don't have any definitive solutions, one of the guys here mentioned that he experienced some of the same issues which improved when going to a long cage RD from a medium. We know it is listed as OK for the difference in number of teeth, but it seems in reality the chain control is better on the longer cage especially when you get further down the cassette onto the smaller cogs. He had the same issue with the chain hitting the spokes etc. which was fixed with the long cage RD.

    We will let you know if we have any more info.

    H
    Hans
    Ibis Cycles, Inc.

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    Can any of you give me your respective chainlines? Whether single ring, middle ring of a 2 or 3 front setup.
    It would be nice to get a consensus re common -optimal CL, versus what is achievable on the SLR (at least).


    .

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    Thanks Hans. I got an email from Scot too with some suggestions.
    Basically I can lift my rear tire up about a foot (I was just in the garage testing this again now) drop it, the chain would come off the front chainring. It comes off from the bottom. So basically, I can not even bounce the bike a foot of the ground or the chain will come off.
    The guys at my LBS have 1x10 setups too with clutch type derailleurs and can drop their rear from 5 feet and chain will stay on(these are on Giant and Yeti bikes). So I wonder what makes my setup so unique that it is so sensitive to such.
    When unloading my bike, I almost have to set it down like it's made of glass. It's also very frustrating to have to get off the bike every ride, loosen my chain guide and put my chain back on.

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    Just some extra info. I have a HD and the funny thing is that I drop the chain more on XC tracks than DH tracks. Doing DH shuttles at Stromlo the other day there was one drop off only in the 3-4 foot range that would have the chain off every time but even bigger drops and jumps and also rock gardens were fine. I think the chain drops more on xc tracks when I do 1/2 or 1/4 back pedal for a corner or some roots/ruts while the chain is bouncing about.

    I tried the back wheel drop test and I couldn't get the chain to come off.
    I wonder if having a chainring meant for a front derailleur with shorter teeth that are designed to deraill might be part of the problem.

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    wow this is unusual. I'm running 1x9 setup in my mojo c with a midcage xt rd and an mrp mini g sl for years now and never drop a chain well I guess just one when I crashed during a dh run when I wasn't able to control the bike due to a very deep rut and that's it.

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    Have you guys adjusted the clutch on your shadow+ derailleurs? Shimano recommends it after a break in period. My XTR started to get a little more loose and noisy after the first couple months so I've tightened it up one time, and have had no problems. I ride 5ish days a week on rocky aggressive trails, plenty of jumps and drops, with no chain guide, and I think I've had one dropped chain in the last 9 months, and that was from a sloppy tech-climb downshift to the granny. Really weird to hear about these problems.... shadow+ has been pure love for me.

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    This is interesting as I was about to move to a short cage zee + rd from my long cage xt as now I'm running 1x9 with a dmr viral chain guide and I was having problems with the chain dropping, ( not often mind you) but it seems I might be better just sticking with the long cage rd then.

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    Mine is a long cage XTR btw, with 24/36 double with a bash guard. Maybe the long cage has made all the difference.

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    I've tried both a long cage xtr and a zee. The long cage was definitely better but it still dropped the chain. I have adjusted both of them nearly to the point of being to hard to change gears. The real problem seems to be the slack before the clutch is activated, which seems to mainly come from loosness/flex in the clutch engagement mechanism. Also while in the higher gears the paralellogram can move in towards as the spring is pretty weak. This cause the chainslap that hits the spokes.

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    recent discussions on related topics

    Check the condition of the clutch: others, including me, have broken it.

    Pictures in this thread show one example of what to look for:
    Has Anyone Else Broken a Shimano Clutch RD?

    Shimano warrantied immediately via my LBS.

    Here is a discussion of long cage/short cage:
    Long cage vs. med cage on 2x10? Does it matter?

    My conclusion from having tried both on, talked to Shimano, and talked to Ibis, is that even though technically the mid cage works for 2x10 setups, the chain growth (on the HD at least) is such that the long cage is a better idea. Otherwise, (as measured on my 2x10 setup) with a chain long enough to handle big-big gearing while bottomed (i.e., worst case scenario), the small small has no tension at all. Not sure about 1x10, but Hans suggests the same applies there.

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    I took apart the clutch today to inspect it and nothing is broken. I talked to Scot also at Ibis and he suggested trying a long cage too. Although I'm inclined to say that I am running a long cage instead of a medium because XTR only comes in Long and Super Long. I really don't think it has to do with the cage length because even when I switch to middle ring where there is tension on the chain, it still pops off.

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    Heres a vid I posted in the drivetrain thread of my drop test. Anyone else having this problem or can mimic it.
    first drop the chain was on outside cog, the 2nd drop the chain is on a middle cog.



    Sorry my feet are in the way

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    I tried picking up and dropping the back end of my sl this afternoon and I did manage to get the chain to drop, but I had to lift the bike pretty high and it probably only did it once in every 5 times I tried. I'm running an xt long cage rd on a 36t single ring up front. Only other point is I could only get it to happen when I had the chain on the lower gears.

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    Quote Originally Posted by Richie82 View Post
    I tried picking up and dropping the back end of my sl this afternoon and I did manage to get the chain to drop, but I had to lift the bike pretty high and it probably only did it once in every 5 times I tried. I'm running an xt long cage rd on a 36t single ring up front. Only other point is I could only get it to happen when I had the chain on the lower gears.
    Thanks for the testing. My buddies at my LBS tried the same test with similar results like yours. I think it has to do something with my HUB as well. We tried a different wheel on my bike and although the chain still came off, there was slight improvement.

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    When I first got my HD I thought I could avoid chain drop just by using the X9 type-2 rear mech and a bash guard but my chain kept dropping from the top of my chainring (1x10 setup) so I fabricated a metal chainstop that attached to my direct-mount FD mount...but I still managed to drop the chain in the rough...I ended up going with a Straitline Silentguide and haven't had any issues since...
    ride, eat, sleep, repeat

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    I'd say that since the rear wheel is not back-spinning and causing your pedals to back-spin that your hub is really loose and able to back-spin when the wheel is dropped, creating a little bit of suspension movement/rebound. It appears that the tension on the chain from the rear derailleur is overcoming the normal tension of the freehub pawls and giving a 1/2 back spin. I have not tried this with my SL-R (3x10, Shimano XTR Shadow+ long cage) to see if I get back spin in that circumstance. I'll try today myself and see.
    2013 Ibis Ripley
    2012 Ibis Mojo SL-R
    2009 C'dale Rize 3

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  21. #21
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    MC, did you ever figure this out? It looks like you sold your slr?

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    Quote Originally Posted by 661lee View Post
    MC, did you ever figure this out? It looks like you sold your slr?
    I didn't. Ended up just using a c-guide that fixed it.
    I did decide to sell my slr 1 week after. Only had that bike for 3 months too. Placed an order for the Ibis Ripley!!! All ready to go. I9 torch, fox talas and all my slr components

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