robdgster

Hello,

I recently updated my Giant Defy (2018 model) wheelset to Mavic Ksyrium UST elite wheels with Shimano Ultegra R8000 disc rotors. I attempted to bed-in the new disc rotors on my first ride with them.

However I’m noticing a bit of “tinny metallic” sounding noise with what “I think” is coming from the front disc rotor. It seems to be most noticeable when I’m at speed, especially when I’m shifting my weight from side to side.

I pointed this out at a service with my LBS last week and they said they would look at them, but nothing has changed when I got the bike back.

Not sure what it is? New rotors need bedded-in more?

Thanks for any help,

Rob

Bigbus

What pads are you running?

robdgster

I think there the default pads that come with Giant Conduct Hydraulic Disc brakes. I’m having no noise with normal wheeling & braking.

August West

With the new wheels the rotor(s) is probably not exactly centered between the pads in the caliper causing a slight rub. If you aren't going to be swapping out wheels you can just realign the caliper on the offending rotor. Lots of YouTube vids on how to do it (very easy). If you want to swap the new and old wheels out from time to time you will need to shim one of the rotors out so they are both centered in the caliper. Note, you can only shim the rotor outward and not inward so you will need to see which rotor is sitting the farthest to the outside and shim the other one to match it. Might or might not have to align the caliper in this case.

Shims

jmess

This tool works pretty well for aligning the calipers when swapping wheels unless one of the rotors is bent. You slightly loosen the caliper bolts and slide the shims between the rotor and the pads. I squeeze the brake while tightening the caliper mount bolts. Seems to work well. Also as the brake pads wear down the need to recenter the calipers is reduced, more of an issue with newer pads.

The Hayes Feel'r Gauge Disc Brake Alignment Tool is easy to use and delivers perfect alignment every time. Insert the steel shims on either side of the disk to achieve appropriate pad spacing; make sure the caliper is parallel with the rotor.

Bigbus

I've always just loosened the bolts, squeezed the brake lightly, held the brake and re-tightened. I'm not sure what the neat looking tool is really for. Once the caliper is adjusted, you simply use the nut on the cable to set how much play you want in your brakes, which is basically how much room between the pad and rotor you like.

CarloM

I had the tiniest bit of rotor rub on my rear hydro brake on my TCR Adv SL1 I took ownership of last week. Fix was super-easy, after I confirmed that the rotor was true (it was). I followed the same procedure Bigbus noted above, no tool necessary outside of the hex wrench to loosen the bolts that attach the brake to the frame (I think it was 4mm but I may be wrong).

If a video is helpful, go to the 2m55s mark of this video:

jadocs

Check the spokes.

Lars Halstrom

Here is a source for shims I just found. https://boydcycling.com/search?q=shims+

Andrew R Stewart 

I love absolutes in marketing blurbs Andy

jp911

I had this issue on my gravel bike (Niner RLT9). Thought it might be the fork flexing or spoke tension because it was pronounced when I was standing and cranking hard on steep climbs, but it ended up being a combination of flex in the system + the caliper pistons not retracting far enough. I opened the bleed cap on the brake lever and then pressed the pistons flush with the caliper using a plastic tire lever (wheel and pads removed). You'll need to mess with the lever reach and stroke afterward, but it solved the problem.