Soft washers sound like a good idea, but how will you keep them on the ends of the axle when you remove the wheel....

Since plastic washers are 'compressable' they will change the relationship from the brake mount to the brake rotor, and with a brake, small measurements are notable.

Maybe not a problem on the drive side.

I thought the sounds were coming from the ends of the axle? Now it sounds like your saying it's the brake rotor? You need to figure out where the sound is coming from, before you can actually fix it.

 

These are definitely the ends of the hub. And previously, these wheels (DT Swiss 350) were on another bike and everything was OK.
So far, the washer option looks like a solution (especially if the sound comes from the brake rotor).

 

Are you sure it's the end of the hub axle caps/stubs contacting the frame and not the axle stubs wiggling a wee bit in the hub shell and creaking/squeeking? Look very carefully and if there are any parts of the end cap or the hub shell missing some anodizing, there is a potential point of noise.

I don't know how difficult it is to remove a Canyon Spectral rear wheel, but on my bikes it only take a few turns of a tri-wrench and Voila'! the rear wheel fall out. If the end of the axle is really all that is causing the noise, this is an easy, repeatable fix.

Use a very thin coating of anti seize on the very ends of the axles... re-install wheel. Anti seize lasts longer than plain grease, but if grease works for awhile, it's better than nothing.

While you are at it, remove the derailleur hanger, anti seize the contact points and re-assemble/torque to spec. And hey, maybe removing, cleaning applying antiseize and replacing with correct torque is a good way to ward off creaking/squeeking.. remove, clean and put something slippery on the contact points. Repeat.

A bike is nothing more than a big pile of parts bolted together. Lots and lots of places for rubbing metal on metal, which causes noise. Look for wear marks, silver spots of warn away anodizing. Clean, apply slipper stuff, reassemble and torque to spec. Tedious but necessary.

DT

 

thin plastic or teflon washer?