CHAINS KEEP FALLING OFF

May 23, 2006

    My 5-year-old son just started riding without training wheels. We got him a second-hand, 18-inch bike. Since then, the chain keeps falling off, even when he is just riding around in the drive. It is very frustrating when we are on family rides and I have to stop every so often to put it back on.
    Is there anything we can do to eliminate this problem?
Delise M.

    My husband just bought a Diamondback bike and the chain came off of it on his 2nd or 3rd ride. There are no instructions in the manual on how to put it back on. Is this something he can do or do we have to return it to the store? He didn't purchase the extended warranty, so I'm not even sure if they will fix it free of charge.
Angela M.


    I suspect the same culprit for both these bikes: The nuts holding on the rear axle have gotten loose, causing the wheel to slide forward. This shortens the distance between the pedals and the wheels, so the chain stays loose and falls off.
    For the kid’s (and possibly adult’s) bike, you can use a wrench to loosen the screw-on axle nuts even more. (See a photo here.) Then slide the wheel into the proper position (it helps to have an assistant hold it there), and tighten the nuts.
    The Diamondback might have a quick-release nut rather than screw-on nuts. In this case follow the same procedure, except you use your hand, not a wrench: Open the quick-release lever, loosen the nut on the other side, move the wheel, then tighten the nut and close the lever. (My book shows this with photos.)
    Last, to fix a problem with a new bike I wouldn’t hesitate taking it back where I bought it. If you got it at a bike shop, the staff should handle it for free. If you didn’t get the bike from a bike shop, well . . . maybe next time you will.

Mr Bike

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