when i use the brakes quite hard on my new bike im getting a "cracking" sound coming from the rear brake.
i can also get the same noise if im off the bike and rock it backward and forward with the brake applied??
ive checked everything is tight and nothing was loose??
only happens if i squeeze the brake hard??
brake is a new style shimano xt trail with ice tech rotor.
its fitted to a 2011 pitch and all the bearings/bushes in the rear seem fine too??
any ideas??
pads moving in the calliper?
is that possible Stoner??
ive noticed the front pads have the fins on them but the rear dont?
should they have??
the pads "float" in the gap in the caliper. They can move fore and aft 1/2 a mm or so. There's also a spring in there holding the pads open. I wouldnt be surprised if the cracking sound is the spring catching against a molding mark or small dent and "clicking". You could try greasing (with just a smear, not a gloop!) the pad backs and backplate sides to see if it helps. Obv keep it off the pad face.
If it's been used, check for a hairline crack along a weld on the seatstay near the brake mount. Last time I dealt with this, the frame was just starting to crack and the brake was causing movement in the crack, hence the cracking sound.
rotor bolts tight?
stoner is correct its the pads rocking on the pin that holds them into the caliper
boom!