I picked up a Trek fx 7.5 the other day, it seemed as if there was a derailer adjustment issue. I noticed that when I was in the middle ring in front, the rear 4 largest gears caused a rubbing noise on the derailer in front. The strange part is that I always thought that bikes would sometimes make some noise if you were on the extreme cross chain situations, on my bike those situations seemed ok though. I brought it back to the shop and it seemed like the mechanic was struggling to get it quiet. He mentioned that the new 2011 design on the deore derailer had tighter tolerances. The strange part is that my brother got the same bike on the same day, built by the same mechanic, and has no issues! The mechanic finally got it to work normally, but it seems that the adjustment is still a little off and drifts. I looked a little more carefully today, and it seems like the front gears have a little runout in them, maybe the thickness of 2 dimes. I have a feeling that this is what is eating up his tight tolerances and causing the rubbing. Is it normal for the gears to have a little runout in them? Shouldnt they spin perfectly straight? Did any of you ever hear of anything like this? I'm really upset, I was looking forward to this bike so much, now I feel like I made a bad decision. I'm taking it back again tomorrow, is there anything I can suggest or request from them? Any suggestions on what it might be? Thanks.
Chris