Disc Brakes and Pads that *DON'T* squeal?

Mountain bikes have always been much quieter for me.

I suspect it is down to a couple points:

  • Bigger rotors that have a different resonance
  • More frame material damping any vibrations/squeals

I also reckon there’s probably something to do with the wheels and their weight/stiffness.

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Possibly, but it generally does not self-resolve without cleaning. It’s just one of life’s little mysteries.

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ultegra rotors? Its dry here in NorCal, and thought it was common knowledge that Shimano RT-M900 are “better” than Shimano road rotors.

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I’ve found that riding pads that have a little moisture in them can cause things to glaze over.

Are you just cleaning with alcohol to fix the issue or does it take some resurfacing?

One method that does seem to work but can be a pain is to heat the pads/rotor when they’re contaminated. One mechanic I know burns pads with alcohol (can’t personally recommended that one), otherwise a touch will work! :man_factory_worker:

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I’m not sure how much better the MTB rotors are in reality.

In all honesty, I find the solid stamped steel rotors much easier to live with than the sandwiched alloy “Ice Tech” ones.

Do some people need rotors that cool as fast as possible? Sure. Do most people? Probably not.

The same goes for the pads with cooling fins. :roll_eyes:

Hated the Ultegra RT-CL800 rotors. Noisy. M900 are better. Just realized I still need to sell my new in box M900 rotors (been sitting here for 3 years :sob:).

Typically I clean with alcohol and then do a cursory rebedding. It takes a few hard braking efforts to return to normal strength, but then it stays perfect unless I leave the bike for a few weeks again.

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Absolutely a possibility…the last few eeks have been very humid in the Chicago area and my road bike brakes squeal when I first hit them.

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I was using the older Ultegra rotors, pre-2021, and seriously they were noisy.

You know it was an issue when Shimano posted this 2 years ago (June 2022):

FWIW, I had a Shimano equipped disc brake bike from 2015-2021. The Ultegra rotors were noisy, after several LBSs steered me to the mountain rotors, I made a mistake and bought a second set in maybe 2019 or 2020. Horrible.

Yes it’s flat here but I also do long mountain descents. The Ultegra rotors circa 2015-2021 were horrible and every LBS I spoke with told me the same thing.

That could indeed be it. I’m a light guy and use resin pads so I don’t see much rotor wear. I am only on my second (I think) pair of rotors on this bike, despite it being 5+ years old now, and the current pair was a backup set I probably bought in 2020 and put on a while later.

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Resin pads too. I’m heavier but it happens to me in the flats where my weight is less of an issue. The pre-2022 Ultegra rotors were horrible for me on long descents, and even shorter ones for example a couple 1.5 mile descents at -10% on crappy roads with rocks and potholes and tree shadows where I have to scrub speed to stay safe. The Ultegra rotors would start howling within a minute or two, there were terrible on that sort of stuff. But even on the flats they would mysteriously start howling. After switching to SRAM in 2021, I was shouting hallelujah to the heavens for the newfound peace and quiet.

FWIW.

Hmm, mine are not like that. Mine are silent and stop well, apart from the frustrations mentioned above.

On the flats my Ultegra rotors would be silent for awhile, and then mysteriously start making noise. The M900 behaved much better.

Long descents? Well I’m 90+kg and a 1.5 mile / -10% descent would be above 40mph within seconds. Modulating the brakes helps, but they would start howling at some point. Starts off as straight shade dappled pothole&rock section, and rotor howling always before the switchbacks.

Return home, time for sanding & alcohol & rebedding.

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Taking the bike from 74 degrees inside and A/C low humidity to 85 outside and 90% humidity causes big condensation. Brakes squeal until I do a few easy stops. I can imagine being outside in humid conditions for weeks might cause a moisture build up and some sort of rust film on the rotors

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as I await the Shimano replacement calipers (dura ace - their best ones),

I bought Galfer rotors and brake pads.

I am going to go to a bike shop for a full re-wiring of hoses and install rather than DIY

i’m selling this bike and getting rim brakes if this doesn’t work.

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And if humidity can trash your brakes like that, why have brakes? #DramaLama?

That’s the main reason I’ve given up! I can have a squawk/squeal free bike, and by the time I ride it, SQUAWK/SQUEAL like it was MADE to do it!!

I heard a comedian how was ranting on simple things that humanity can’t seem to get right, and wondered, to great applause and clapping ‘I can only wonder if the people saying the moon landing was faked have been right all along!’.

Imagine your car brakes doing that! They DID at one point. What stopped it? Thicker rotors? I bought a new set of rotors and pads not too long ago, and they now sound like they have been buried in a bog for 6 months, rather than sitting in my basement!

I GIVE UP…

AND I think they are SOLID rotors, no All Clad cookware steel aluminum sandwich. Were those rotors designed to cause noise? I’m being partially tongue in cheek, but the number of people complaining about it is pretty huge.

Aren’t those the XTR rotors? I thought I was the only one that tried that trick. They did last a bit longer, but ended up sounding like a herd of geese in heat. sigh And then I bent one. :roll_eyes: :person_facepalming: :flushed:

I mentioned that to the head mechanic at the one best LBS, and he rolled his eyes and groaned. ‘No, it doesn’t end up working, and can cause delaminating. grunt

I’ve used ultra fine sand paper, and a brass drill brush and gotten ‘better’ results, but be very careful that the pads are sanded evenly. Yeah, it’s pretty easy to ruin a pad.

I did try Dura Ace rotors, and they seemed to be quieter. Until they weren’t, but I think they lasted a bit longer for some reason before honking started.

Again, is there a solid rotor for center lock hubs, or do I have to use an adapter to test the idea that solid rotors are quieter?

Having first tried disk brakes 6 years ago, and encountering these issues, then gone to rim brakes I wondered if brakes still squealed. I hated it at the time. I heard a few honk in the tour and guessed so.

SM-RT10 I believe.

Although I’d also look into other things if you haven’t (pad/caliper alignment, seals, contamination from somewhere etc) as noise beyond the odd screech in the wet is not normal to me.

I haven’t looked for rotors in a while, and am shocked that so many models are unavailable. It seems like we are neck deep in the pandemic again. Yikes…

EDIT: But I did walk in to a smaller local bike shop during the Great Pandemic and discovered they had an Ultegra chain, and a pair of Dura Ace brake rotors. SCORE