Disc brake rubbing
 

I did search the forum but surprisingly could not find an answer. Possibly the best titled thread quickly devolved into a debate on the merits (or not) of disc brakes (https://www.bikeforums.net/bicycle-m...kes-rub-2.html)

My DB gravel bike has Shimano BR-RS805 hydraulic disc brakes. It's my first bike with disc brakes so I haven't figured out how to maintain them yet, but I'm willing to learn if someone can point me in the right direction.

The bike is fairly new--less than 500 miles--and no crashes. The front disc is rubbing on the calipers and I can't figure out how to get rid of the noise. I guess the easiest thing would be to open up the space between the pads and the disc but I don't know how or if that's even possible. I've tried loosening and then tightening the quick release but the thru axle doesn't really allow you to slant the wheel like you could with a QR skewer.

Sometimes the noise will go away and then return. I thought maybe the wheel/spokes are deforming on different terrain and causing the disc to warp in and out of true. The wheel does appear to be true, though. If I lift the front of the bike, hold it level or slightly angled to the left side, and spin the wheel, the disc rubs the pads. If I tip the bike to the right side, and spin the wheel--no rubbing noise. The noise is more pronounced when the bike is tipped to the left compared to being held level. There is no wobble in the wheel if I try to jiggle the tire back and forth so the QR is clamped down tight.

Where I should start looking to fix this issue? Maybe the solution is to find the offensive spot on the disc and tweak it in the opposite direction with some pliers?

Thanks,
Paul

So the rub is against the caliper and not the pads?:)

Remove the wheel. Place a thin stiff AND clean strip of metal (we use a cone wrench after wiping it off) between the pads and twist/pry the pads apart. Reinstall the wheel and cycle the lever a few times to reset the pads position within the caliper. Then go back and recenter the caliper over the rotor. Make sure the rotor isn't warped or bent.

Do know that bikes have some flex add movement between the various parts. This is why the trend to stiffer axles and such is happening. The fork is far more flexible then the rear end is so front rub, especially when side forces are at play (standing up and working the bars, cornering) some rub is common but not wrong. Remember that auto disk brakes rub all the time, just not with any real *********** force till that pedal is pushed. Andy

********** is "slowing down"

Andrew, thanks. I should have known the difference between pads and calipers because I have changed the brakes on my car a few times. Duh. I do know that car pads rub the rotor the whole time, but I don't have a 180hp engine or the radio to cover up that sound. It's just really annoying.

I'm going to look through YouTube for some visuals. I don't mind prying off the pads on the car with a big screwdriver but doing the same to my little 'ole bike? Maybe not so much.

Andrew has given you some very sound advice. Just make sure you're pushing the pistons in fairly straight. The calipers aren't all that delicate. Remember they put out a pretty large amount of clamping force and have to withstand all kinds of twisting forces and abuse during their lifetime.

I love YouTube. The fix was easier than I thought. I just needed to recenter the caliper. Loosen 2 bolts, squeeze the brake lever, and tighten down the bolts. Done. No more noise.

Thanks guys

Paul

Paul- Great! And thank you for using your birth name. Andy