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  1. #1
    Trips for Kids Denver
    Reputation: twowheelfunman's Avatar
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    Stumpjumper ripping off hangers

    I have a buddy that recently bought an 07 Stumpjumper with a brain shock, XO R. Der, XO thumb shifters, sram cassette & sram chain.

    He put in several rides & then decided to go on more challenging rides with me. We were riding in Fruita over the weekend and going up a long climb on Lions Loop I hear this "pop" behind me & his R.Der is hanging off with the hanger ripped off toward the spokes. So much leverage was applied to the R. Der that the low gear limit screw was ejected from the der body. We made it a single speed & finished the ride.

    He bought 2 more hangers, a couple low limit screws and a chain. We rode Green Mountain in Lakewood, CO a couple days later and the exact same thing happened again.

    Are Stumpjumpers prone to doing this in general? Are they SUPER sensitive to downshifting under a load? The hanger is really thin IMO with no rearward support.

    Thanks
    " I'm not inclined to resign to maturity "

  2. #2
    Dirt Deviant
    Reputation: savagemann's Avatar
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    Here is a much more likely scenario.
    His low limit screw is falling out, THEN this causes the der to shift into the spokes and rip the hanger off. I would be very suprised if this wasn't the case.
    Sounds like he needs a new rear der, and or some loctite on the limit screw.

  3. #3
    Trips for Kids Denver
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    The XO r.der limit screws include a plactic bushing that serves as a stress relief of sorts. His low limit screws were there and adjusted properly both times. I think there is some type of binding happening where the chain gets held but pedaling stretched the r. der backward until the hanger gets ripped in half.
    " I'm not inclined to resign to maturity "

  4. #4
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    Bad freehub maybe?
    Are his der pulleys rolling smooth?

  5. #5
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    Reputation: sanjuro's Avatar
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    I worked for a Specialized dealer. Never heard of such a problem. I wonder about the missing low-limit screw. Methinks, a derailleur adjustment review is in order.

  6. #6
    Trips for Kids Denver
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    Good to know that it shouldn't be a common problem with Specialized. After the first time it happened he got a new hanger and low limit screw and bushing.

    We took off the old chain, installed the r. der, set low & high limits, installed a brand new 9 speed chain, set the b limit and set cable tension. Tested it on flat ground and he said it was shifting better than it ever has. We rode about 45 minutes on a trail that has many short steep climbs and on a climb that has less grade than most of what we had already done it happened a 2nd time.
    " I'm not inclined to resign to maturity "

  7. #7
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    Savageman gave you the most likely sequence of events, or possibly the inner limit wasn't tight enough in the first place.

    Follow this sequence for the safest way to adjust the inner limit. Overtighten it until you cannot shift to low gear, then back it off incrementally while testing the shift. Stop when you can just to shift to low, then bring it in a quarter turn and re-confirm that it needs to be out that last quarter turn. BTW- if it doesn't need a bit of torque to turn, it might walk out over time, so use locktite or rubber cement to help keep it in place.

    There might be an entirely different cause of your friends grief. I see many bikes set up with the RD too close to the cassette. It improves shift response on the smaller cogs but causes interference between the upper pulley and larger cogs. Next time adjust the "B" screw and/or chain length so that on the larger cogs there is a clear gap with one inch of chain free between the jockey wheel and the cog. If the jockey wheel, chain and cog are in three point contact, the derailleur sometimes gets kicked back putting great strain on the hanger.

    Otherwise, I doubt that there's a design problem with the bike, it's how it's set up.
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  8. #8
    Trips for Kids Denver
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    Thanks, I have a few things to look at & try. I'm suspecting the low limit screw is backing out.
    " I'm not inclined to resign to maturity "

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