Grinding noise

alexwhite.sm

My claud butler d27 (hydr. disc brakes etc) which i bought 2 weeks ago has been making a grinding noise, whcih i think comes from the disc brakes, but i am not sure, ever since i got it. I took it back to the bike shop today but they couldnt find anything wrong. Any ideas as it certainly shudnt be making alarming noises!
cheers

supersonic

Is it grinding under braking? Many discs make noises when braking.

Could try the Park Tools article on diagnosing noises - but if you are still unhappy, demonstrate the noise to the shop.