Dura Ace 9100 rear brake squawking?

[bushpig]

Mine squeal horribly too. I switched from 9000. I have tried all the suggestions here and have have swapped out different wheels to try. It has something to do with how stiff the arms are. I think that what is happening is that the seatstays are flexing rather than the caliper. I have currently "solved" by ridiculous (2+mm) of toe. As a consequence, the feel is terrible. More to come.

[tylercheung]

The other thing I did not check for, but helped once fixed....lateral play in the rear hubs. Guess I need to be better about servicing that thing...

[BdaGhisallo]

I have had this problem too with the 9100 rear caliper and it has been driving me nuts. It's less a squeal that you would traditionally know and more of a vibration kicking off some resonance in the bike.

I recently did some experimenting to try and find a solution.

I tried three different wheels - Enve w the text brake track, Bontrager Aeolus XXX 4 and Shimano 9100 C40. All are tubulars.

I tried them all with their own native brake pads. I tried mixing pads and wheels. I tried mounting the pads flat to the rim. I toed in the pads, first a little then a lot. I even tried toeing-out the pads.

I cleaned the rims. I sanded the pads. Both the Bontrager and Shimano wheels and pads were brand new so there was no question of pad material buildup on them. They exhibited the vibration from their first mile. The vibration was so severe I could feel it in the top tube and it radiated up through the saddle and tingled the bits.

Nothing that I tried fixed the vibration with the 9100 caliper.

My solution: mount my old 9000 caliper. Silence! No vibration! I mounted the pads flat to the rim and things are working great. And I, too, have never had an issue with the front 9100 caliper.

[mcteague]

Originally Posted by Davist

I was going to suggest no toe in, the new arms are so stiff... I've basically gone away from toeing in any more.

Me too. I loosen the bolts to the pads, apply a bit of pressure from the levers, align the pads and tighten the bolt. Never had a peep from them. This is with Campy brakes by the way.

Tim

[Avispa]

I had a noise problem with Shamal Mille rims and Campy brake pads. I discovered that when used a lot in very dry conditions, these rims attracted brake dust and micro road grime in the grooves of the rims, thus creating the noise. No matter if the pads were correctly aligned.

The only thing that was able to quiet the noise was when I applied the Pedro's Frame Polish to the rims to clean them. This is the white liquid sold in squirt bottles that looks like milk. On the Shamal rims, this stuff dried quick, left no bad residue and didn't affect the braking performance.

[muz]

I have a simple solution: just use the front brakes

Once I was 80 miles into a ride when another rider pointed out that rear straddle cable was disconnected. I had not touched my rear brakes up to that point!

[Jeff N.]

Originally Posted by muz

I have a simple solution: just use the front brakes

Once I was 80 miles into a ride when another rider pointed out that rear straddle cable was disconnected. I had not touched my rear brakes up to that point!

I have an even simpler solution: Live with it.

[Team Murray]

I have the rear, direct mount, 9100/Mille/ Campy pad squeal problem. Toe in didn’t help. Going to Vittoria’s PEO pad helped but they wear very fast. I believe the pad material shears easier.

What I found worked was to swap the front and rear pads. Noise gone.