[funkymonk]

Hi, I bought a new Trek 1.1 from a Trek dealership last week. I love the bike itself, but the chain ring wobbles 3-5 mm per rotation which causes the chain to rub the front derailleur when I'm in the highest two/three gears. I'm going to take it back, but my question is, am I likely to get a free replacement or should I expect the mechanic to take the chain ring off and knock back into shape? Or is there any other likely outcome? Thanks for your help.

 

[wim]

That's a lot of wobble. If it is, in fact, a bent chain ring, I would expect the shop to replace it. Bent rings can be straightened out without too much trouble. But this is a new bike, so ask for a replacement ring. Keep in mind that excessive chain ring runout can have other causes, so let the shop look at the entire crank and the bottom bracket first.