Dura Ace 9100 rear brake squawking?

[tylercheung]

Has anyone else had issues w/ Dura Ace 9100 (rim) calipers squawking on hard braking? I've been trying to diagnose this over the past few weeks. I've narrowed it down to the rear brake; front brake can brake hard w/o noise. The rear will squawk on hard braking. I've re-aligned the pads and toed it in ~ 1 mm, but still happens. They are on Archetype alloy rims which look pretty clean to me, connected to Ultra 6800 levers. I may try to toe in 2 mm, or maybe just have the LBS mechanic look them over....

[oldpotatoe]

Has anyone else had issues w/ Dura Ace 9100 (rim) calipers squawking on hard braking? I've been trying to diagnose this over the past few weeks. I've narrowed it down to the rear brake; front brake can brake hard w/o noise. The rear will squawk on hard braking. I've re-aligned the pads and toed it in ~ 1 mm, but still happens. They are on Archetype alloy rims which look pretty clean to me, connected to Ultra 6800 levers. I may try to toe in 2 mm, or maybe just have the LBS mechanic look them over....

Squealing means they are vibrating..more toe and clean rims..maybe take a rasp and rough up the pads..Make sure the caliper arms are not loose. Caliper tight into the frame.

[fkelly]

I've had same problem with brakes that were installed as part of a DI2 installation. Rear brake only. Started with vibration, then squealing on steep downhills. Gone through several cycles of cleaning rims and pads. After one cleaning they squealed for about 5 miles, then stopped. I've tried Simple Green and citrus degreaser followed by a thorough rinsing with plain water. Yesterday I used fresh paper towels so I would see any gunk being removed, then rinsed thoroughly, then they were still making noise. Then they stop halfway making noise through the ride.

I'll check the toe in and caliper tightening recommendations. It's the intermittent nature that's the hardest part. If it was constant I'd be at the shop that installed right away ... though I know that toe in and caliper checking is something even someone with two left thumbs like me can do.

[oldpotatoe]

Has anyone else had issues w/ Dura Ace 9100 (rim) calipers squawking on hard braking? I've been trying to diagnose this over the past few weeks. I've narrowed it down to the rear brake; front brake can brake hard w/o noise. The rear will squawk on hard braking. I've re-aligned the pads and toed it in ~ 1 mm, but still happens. They are on Archetype alloy rims which look pretty clean to me, connected to Ultra 6800 levers. I may try to toe in 2 mm, or maybe just have the LBS mechanic look them over....

Another thought..I had a bike, altho disc brakes, that had a rear that sang like a stepped on cat..turns out it was the rear triangle, too thin, to soft, flexy..'might' be the brake bridge/seat stay stiffness...Not sure how to correct but...

[AngryScientist]

another thing to check is the rear hub. if there is some lateral play in the bearings, or if the QR isnt nice and tight, you can get some vibration out of the rear under different circumstances.

[David Kirk]

I would try lightly sanding the brake pads to scuff them up and then wipe them with alcohol and I'll bet you'll be good.

dave

[bikinchris]

I would take the tire off.
Wipe rim with acetone. Use sandpaper or wood rasp and scuff up brake pad.
Stick a thumbtack in the rear edge of the brake pad. Then set the toe with the thumb tack in place. Remove thumbtack and remount tire.
Check rear wheel bearing adjustment.


Other than that, it might be something else causing the squeal.

[tylercheung]

ah ok.

I was worried that this might be something w/ 9100's...did not have this issue w/ 6800...now I miss those brakes!

I toed them in about a mm, but will try maybe a little more, plus scuffing the pads and cleaning the rim.

[simonov]

ah ok.

I was worried that this might be something w/ 9100's...did not have this issue w/ 6800...now I miss those brakes!

I toed them in about a mm, but will try maybe a little more, plus scuffing the pads and cleaning the rim.

Did you recently install the 9100 and has it squealed ever since installation? I once had a rear that squealed no matter what I did and it turned out to be an issue with the brake's stiffness (which caused the vibration mentioned above) and the only solution was to replace the calipers with a different model (old Force to new Red). The new Red caliper was silent from day one.

[tylercheung]

They're new-ish, but they only really started squawking after ~100 miles? I certainly hope they aren't brake-related...I guess I didn't really need to upgrade them, just the 9100s were hyped to be "43% better" :mad:

[zmudshark]

They're new-ish, but they only really started squawking after ~100 miles? I certainly hope they aren't brake-related...I guess I didn't really need to upgrade them, just the 9100s were hyped to be "43% better" :mad:
43% better = 43% louder. They mis-spoke ;)

[tylercheung]

Well...I think it's fixed...for now...

step 1: clean rear rim and sanded brakes, cleaned brakes. Still squeaking

step 2: decided to fiddle around w/ pads. Already toed in 1 mm, but I noticed they were not flush on the vertical axis (rotated out a bit). So I figured I'd try to get the pads flush w/ the rim surface...but easier to do this but with NO toe in.

So I figured I'd test this with no toe in, 1 mm toe in, and maybe 2 mm toe in. Lo and behold, no squeaking with 0 mm toe in!!! I guess maybe getting more of the pad in contact w/ the braking surface outweighs toe-in or something.

Also the rear seems to be braking better than the front. Maybe I should clean the front.....:rolleyes:

[tylercheung]

43% better = 43% louder. They mis-spoke ;)

Ain't that the truth!

[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.

[madsciencenow]

ah ok.



I was worried that this might be something w/ 9100's...did not have this issue w/ 6800...now I miss those brakes!



I toed them in about a mm, but will try maybe a little more, plus scuffing the pads and cleaning the rim.



I’ve got a pair of 6800s I’ll swap you for your 9100s ;)


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[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]

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 :banana:

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.]

I have a simple solution: just use the front brakes :banana:

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.