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New Ultegra Crank Wobbling(3 posts)

New Ultegra Crank WobblingCaper
Mar 24, 2002 4:09 PM
I just bought a new Trek 2300 with a Ultegra crankset (double). When I spin it (with no chain) it wobbles from side to side about 1/8 inch, looking down at it. Is this normal? Has anyone else experienced this? It looks as if it's the bottom bracket, as both rings wobble in the same manner. I suspect that it won't affect the shifting of the bike.

Thanks for your help!
Take it back, Shaun...wobble not normal(nm)samcat
Mar 24, 2002 4:25 PM
Not the BB or "the crank"Kerry Irons
Mar 24, 2002 7:36 PM
It is most likely one of the spiders on the crank. These are relatively easy to straighten, and they do get bent just from the bike falling over on the crank if the force is all on one of the spider arms. You can determine if this is the problem by seeing if the "wobble" is at the chain ring bolt point. If so, you can straighten it by laying the bike on its side, with a block of wood supporting the the crank where it attaches to the BB. You want to tap lightly (again use a block of wood to protect the crank spider) with a hammer to move the offending part back into the same plane as the rest of the crank spider arms.

If this is a brand new bike, that you have not mis-handled in any way, then you have a legitimate complaint with whomever you both this from.