Twice in the last two months I think my rear caliper has shifted ever so slightly to cause the rotor to rub on one side (SRAM Rival Flat Mount). First time it was more severe (like roll bike forward a foot and hear a loud screech) and today it's a 'ting, ting, ting' as the wheel spins. First time I brought it a shop (didn't know the cause - duh) and they adjusted and torqued it. This time I've fixed it (loosening bolts, squeezing brakes, tightening bolts).
It's fine that the fix is straight forward, but what is a common cause of this happening? My thinking is braking on harsh gravel roads may jar something loose. The bike was just inspected and all was in order (rotors relatively straight, no bleed necessary).
I have not had this issue before, but I do have some (obvious?) thoughts: - Do you have a torque wrench and do you know the recommended torque for the callipers? - Did you inspect the thread on the mounting bolts, rear calliper and fork (if it happens on front as well)?
I have never had this problem. It has nothing to do with braking on gravel roads. Mountain bikes go over much rougher terrain and do not have this issue.
I have this issue all the time on my Sram Guide brakes on my fat bike (I hate them). I figured it was because the pistons seize up so often that the brakes aren't squeezing evenly and then the pads wear unevenly. I could be wrong.
It isn't an issue with my TRP Spyres on my commuter and I haven't ridden my newer Ultegra gravel bike in the winter.
Sounds like you got your issue handled. But if it happens again, make sure you don't have a sticky piston. (If one is stuck and/or lazy, it is plausible that uneven hydro pressure during braking is moving your mount.....a surprising amount of pressure is involved.)
Stuck Piston's can be somewhat common depending upon your riding conditions and cleaning process. Makes it so they don't retract off the rotor after braking causing them to ride/bounce on rotor until they get bumped back and/or one side not extending to rotor at all/one side doing all the work
Tends to show up most often when pads are nearing their useful life and/or if pads have been replaced and the pistons were't cleaned prior to piston reset.
Sticky pistons are generally easy to fix. I recommend lightly flossing them as part of general maintenance to avoid issue. Make sure to reset (fully squeeze/lock in both pistons) prior to installing pads after cleaning (or if brakes get depressed while rotor is out)....and don't squeeze in a dirty piston (clean it first). (Lastly, don't touch the pads or get cleaner or oil on them while they are out).
I would also recommend new pads if you suspect a piston has been stuck a while (uneven pad wear). Pads are relatively cheap to buy.
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