Was it SRAM that had ‘floating rotors’? I think they were originally for MTB brakes, but an interesting idea.
Was running RT900 rotors for about a month now using resin brake pads and they squeal like mad i changed them to the RT66 basic cheap rotor and some New Brake pads and they have been perfectly fine since i did do a full bleed but what gets me is the cooling fin on the rotor its like a tuning fork and im guessing that where the noise was coming from.
The squeal on the front of my Aethos is so bad now that it feels violent. There’s another thread on here that recommends slathering Pink Stuff paste on so I’m going to give that a go tomorrow. Three other things I’d like to try
- facing the mount - if I can find a local shop that has the tools/inclination
- new pads - currently have sintereds as it’s all the shop had in the day I needed some, resin should be quieter, yes?
- new rotors - currently on the blingest Shimanos, RT-CL900. They look pretty, but are they in fact garbage? I’d like to put a basic one-piece rotor on, a la RT66, but I’m centerlock.
So, as to why I’m posting really:
Does anyone here have any experience with a particular model of CL brake rotor that squeals less than others?
Thanks!
2mm rotors should at very least change the resonance of the brakes. Magura rotors are that thick but I’ve not seen 140mm ones.
I’m pretty sure that Shimano calipers can take thicker rotors but can’t confirm personally.
I checked to see if this is a follow-up post. But all of the options you have listed are on the extreme end of things. Have you done the following basic things:
- Have you checked your brake pads for wear?
- Have you checked your rotors for wear? They should be at least 1.55 mm thick.
- Have you cleaned your brake pads and your rotors?
- Have you checked that your rotors and brake pads are not contaminated? That may happen when you e. g. clean your drivetrain and are not careful. I usually like to zip tie a plastic bag over my brake calipers.
- After thorough cleaning, have you bedded in your brakes again?
Even if your brake pads look fine, I’d replace them with something new. Make sure to clean your rotors very carefully and to bed in your brakes. The second step is crucial, it will deposit some resin (= the material road bike brake pads are made out of) on the rotors, and reduce squealing.
Recent new pads and I cleaned the rotor as well as I could with a specific DB cleaner and then 99% IPA. Caliper is as straight as I’m able to get it, with a lot of time/patience. Rotor is NOT perfectly straight, but frankly I’ve had brand new ones out of the box with more wobble, so I’m reluctant to replace it. Certainly not worn beyond 1.55mm, hardly at all.
I do know about the importance of a proper bed-in, though I do wonder if I failed in this instance.
As for cleaning, I use no sprays, in fact I tend just to use some “Big Wipes” wipes and call it done. Chain is immersive waxed.
One tip I have for anyone else reading (and of course you’ll take advice from me, someone with violent brake squeal 
) is to avoid braking to a stop and then staying on the brakes. Your rotors and pads will both be hot, and if you stay on the brakes (as is common/instinctive), the pads stay in contact with the rotor, and you’ll get an uneven amount of adhesion of pad material to the rotor. I dare say ideally you don’t even want to brake TO a stop - brake down to 1mph, then get off the brakes and stop via other means, when possible!
New L05As on their way. I’m hesitant to replace the rotors due to the exorbitant cost, so I’ll give another try at cleaning/aligning… if they still squeal I’m going to try that so-mad-maybe-it-just-works Pink Stuff paste idea… I guess if that’s still no bueno I’ll splurge on a rotor.
If the rotor is not straight, then this can definitely be a source of noise. You can bend them straight with tools. If you don’t want to do this, go to your LBS and have them straighten out the rotor.
When I bought my second-ever road bike (my first serious road bike), I got it used from someone who got frustrated with disc brakes. He still avoids hydraulic disc brakes. My then-LBS was able to fix the problem within literally 5 minutes. The calipers needed to be realigned. Sometimes small things can make a big difference and someone with experience can solve the problem very easily.
Like I say, not PERFECTLY straight, but as good as I can get it, and it doesn’t rub the pads at all when I’m off the brakes, so that’s PRETTY straight, given the bugger-all clearance Ultegra 8170 gives us. (IIRC Dura-ace calipers give you a tad more)
From my experience, this is exactly it: if your rotor is bent at all in any place, there is more likelihood of squeal. Does not necessarily mean you have to use a tool to straighten it (for me it doesn’t even really work that well), but what helps is if I perfectly align the caliper so that the bent part doesn’t touch the pads at all.
If it does mine also does like a ringing sound if I move the bike in a certain way (took me some time to figure out what that was). Like if I angle the front wheel to fit into an elevator it would do that.
When I properly align the caliper it doesn’t do that sound and the squealing is much less frequent if at all on many rides.
Best advice I was given when I had horrid honking brakes. Don’t mess about sanding pads (I had and the noise came back). Fit new ones. And change how you brake. Brake harder and shorter.
Been silent ever since.
That or just don’t brake.
I got a top-100 all-time down Alpe d’Huez the other day. I’m not a brake-dragger, I can promise you that
(Including lairy rear wheel lock-up into that crash netting corner because I was trying to use my violently-squealing front brake less )
Just apply a bit of common sense, harder braking when you can to keep the pads in good condition.
Ive a solid top 17 hundredth It was on the way to the start of my 2013 Marmotte in a large group so I couldn’t go any faster, well that’s my excuse and I’m sticking to it
This was at the end of my first time around the marmotte loop - which was (by some margin) my longest-duration and most-elevation ride, coming in as you know at 5500m or so.
The views from Galibier were stunning. I didn’t notice any views from Ad’H, too busy suffering on the way up and pinning it on the way down 
This very well could be it. If it is, nothing else you do will fix the problem for good. And unfortunately poor facing of BBs and brake mounts is more common than it should be
To check this, loosen your caliper, carefully align your caliper while gently pulling the brakes, while still holding the brakes tighten the bolts slowly and evenly. If the caliper didn’t remain aligned it’s because the mounts are crooked and need to be faced.
Don’t forget to add seat posts. That’s why threaded BBs won’t bring the relief people think it will, poor adherence to tolerances will shine through everywhere.
Also, it will help if you ask a professional to do it. 2017 I bought my first proper road bike. I got a super great deal for a used Cube road bike with great specs (carbon frame, 105/Ultegra groupset, etc.). But the previous owner got rid of it, because he had issues with the brakes. He told me after it had arrived. I went to my LBS and had the bike checked. As part of that, he fixed the brakes within 5 minutes, he cleaned the rotors, pads, undid the caliper bolts, held the brakes and tightened them. I never had an issue with them being out of alignment.
The other guy still tries as hard as he can to get hydraulic disc brakes, something that gets increasingly difficult.
I had this issue on my gravel bike. It was my learning curve for the different rate of wear on some offroad equipment; I didn’t realize I had to check more often than with a road bike.
I ran the rear pads down to the springs without realizing and scored the rotor. I got lucky that I was able to replace the pads and sand the rotors. Dodged a bullet there.
Yup, and it depends on conditions. If you go out when it is still wet and your route is gritty, you may use up your brake pads a lot more quickly. I think in the off road (car) world they claim 1 km off road = 10 km on road. While I don’t know about the numbers, the argument is solid, riding/driving off road is much harder on your equipment.