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  1. #1
    astrositupataphysicyclist UBUvelo's Avatar
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    chain is jumping off: is it because...

    recently took off the useless (or really, unused) front derailleur (reducing my cx conversion to a 6-speed!), but last week, after two hard training days, the chain jumped off....and off again.....and again......would keeping the derailleur on (though cableless) keep the chain from slapping off or was that just some hard riding?

    it's down to 2 days before my first race...i feel pretty prepared, but i am already at a disadvantage as it is with being a cx noob on a 1990 steel schwinn with minimal modifications (front rim is finally alloy and not steel!). it's actually working pretty good these last 3 weeks with the tires on. but it will suck if i have to stop and get that chain back on every other lap.
    Last edited by UBUvelo; 11-06-09 at 05:52 PM.
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    2008 GT Peace 9er singlespeed--small (goatcross)
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  2. #2
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    If you're running a single ring with gears you need to either leave the derailleur on (you can remove the cable) or add chainguards.

  3. #3
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    if your chain is too long that will defeat a lot of chain retention devices
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  4. #4
    astrositupataphysicyclist UBUvelo's Avatar
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    Quote Originally Posted by funurdiesel View Post
    If you're running a single ring with gears you need to either leave the derailleur on (you can remove the cable) or add chainguards.
    i don't think my chain is having a slack problem, but...

    but yeah, i guess i need to put my derailleur back on...cable is long gone...shouldn't really add any real weight back on...

    of course, is it a matter of how i shift and keep pressure on the chain as i pedal?
    .0000000000000000000000000000000000000000001 after the big bang

    2008 GT Peace 9er singlespeed--small (goatcross)
    2010 GT Peace 9er singlespeed--medium
    2004 Bianchi Axis 1x9 (cyclocross)
    1993 Giant Avonni (mutantcross)
    2009 Giant Defy 2 (cobblecross)
    1990 Schwinn Caliente (medicinecross)
    2009 Giant Yukon FX (root/rock/mudcrosscountry)--recent addition: RockShox Revelation U-Turn

  5. #5
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    Quote Originally Posted by jonestr View Post
    if your chain is too long that will defeat a lot of chain retention devices
    +1,
    also if you RD spring is weak.
    also your chain or gear teeth could be too worn.
    try a chain keeper and guard-
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    Last edited by martianone; 11-07-09 at 03:15 AM. Reason: ps

  6. #6
    astrositupataphysicyclist UBUvelo's Avatar
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    Quote Originally Posted by martianone View Post
    +1,
    also if you RD spring is weak.
    also your chain or gear teeth could be too worn.
    try a chain keeper and guard-
    though this is a vintage bike (nearly 20 years or so), i don't think anything is worn out yet...but not the greatest components either.

    i think the 3rd Eye chain watcher will work...for the price it can't hurt to try it. thanks.
    .0000000000000000000000000000000000000000001 after the big bang

    2008 GT Peace 9er singlespeed--small (goatcross)
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    2004 Bianchi Axis 1x9 (cyclocross)
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    2009 Giant Yukon FX (root/rock/mudcrosscountry)--recent addition: RockShox Revelation U-Turn

  7. #7
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    i would take a few links out of your chain before you go adding a bunch of stuff. A chain can look short enough without actually being short enough. It's less critical when you have your FD on, so you end up with a chain too long. Plus, assuming you took the big ring off, there's no need for the extra links that would allow it to go over that ring.

    You may also want to adjust your chainline (as far as no weight/no money solutions go), but I bet too much chain is your issue--previous threads on this issue suggest that this is by far the most common problem.
    1988 Miele Azsora

  8. #8
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    Quote Originally Posted by UBUvelo View Post
    though this is a vintage bike (nearly 20 years or so), i don't think anything is worn out yet...but not the greatest components either.

    i think the 3rd Eye chain watcher will work...for the price it can't hurt to try it. thanks.
    dog fang works better
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  9. #9
    astrositupataphysicyclist UBUvelo's Avatar
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    Quote Originally Posted by jtgotsjets View Post
    i would take a few links out of your chain before you go adding a bunch of stuff. A chain can look short enough without actually being short enough. It's less critical when you have your FD on, so you end up with a chain too long. Plus, assuming you took the big ring off, there's no need for the extra links that would allow it to go over that ring.

    You may also want to adjust your chainline (as far as no weight/no money solutions go), but I bet too much chain is your issue--previous threads on this issue suggest that this is by far the most common problem.
    thanks! i'll have to look into this after the race...i have finagl'd 'shimano shark fin' for the time being used in a way it wasn't quite intended...LBS had nothing in stock but one of those in the bargain bin for $3....
    .0000000000000000000000000000000000000000001 after the big bang

    2008 GT Peace 9er singlespeed--small (goatcross)
    2010 GT Peace 9er singlespeed--medium
    2004 Bianchi Axis 1x9 (cyclocross)
    1993 Giant Avonni (mutantcross)
    2009 Giant Defy 2 (cobblecross)
    1990 Schwinn Caliente (medicinecross)
    2009 Giant Yukon FX (root/rock/mudcrosscountry)--recent addition: RockShox Revelation U-Turn

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