Originally Posted by
markjenn
I took the bike into the LBS a couple days ago complaining about the clunk and they said it is due to the brake pads shifting in the calipers and is normal. I can duplicate the clunk easiest by holding a brake and rocking the bike against the locked wheel and it does seem to happen with the rear wheel a bit too, so this sorta makes sense.
Yes, that noise is pretty common. I have two bikes with Shimano M315 hydraulic brakes, and one of them will make that noise pretty easily while the other one won't. Both have the stock Shimano organic brake pads. I think it's just a function of the specific caliper and specific pads. If your caliper is a hair on the larger side (in terms of machining tolerances) and maybe your brake pads are a hair on the smaller side, you might have more of a gap than other bikes, and get more of a noise.
Also, I think frame material can highlight this noise more than others. My noisier brakes are on my Giant Roam, which seems to have pretty thin aluminum tubing, and a noise like that seems to travel through the frame pretty easily. My bike with the quieter brakes is a Redline mountain bike which seems to have thicker tubing, and sounds like that are a little quieter or duller in that frame. That could be a contributing factor in your case as well.