I recently bought a Trek CrossRip that came with Avid BB5 mechanical disc brakes, 160mm front, 140mm rear for a commuter. When I am riding down the road, everything is fine until I come out of the saddle and put a little pressure on the front end. It seems that the rotors are rubbing the inside of the caliper. The sound it gives off is like something hitting the spokes, but it only happens on the front. The bike came stock with Bontrager Nebula 32 spoke wheels and Formula hubs.

I have tried to adjust the pads some and that seemed to have helped a little, but it still happens. The LBS also adjusted the brakes a bit....but it is still happening and it is bugging the crap out of me.

Is this a normal issue with disc? possible wheel flex issue?

I'm coming from a rim brake background and don't have the knowledge of issues with disc brakes and I cant really find anything really defining on this. I weigh in at 208 but as this is a commuter, I am also not putting a lot of torque on the bike, but what to see if I can eliminate this.

Any help would be great.

Brian