Apparently not. 
Yep. My suspect is sweat; I wax my chain. I sweat profusely, like a Precision Hydration case study profuse.
My only relief came after I removed the rotor and sprayed everything with brake cleaner from the auto parts store, then wiped and flossed the calipers/pistons.
A cursory alcohol spray & wipe on the bike doesnât seem to do it for me.
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And car disc brake pads need glue on the back plates to help them adhere to the shims and pistons. It makes me wonder of bike disc pads might need some form of adhesive on the backing plates to keep them from riding on the rotor face. I have to admit that I donât know the physics of car brake pad interactions, but if using pad glue does serve a purpose (is it really needed? Iâve always used it) then could it be something to look at for bikes? I donât know what someone could use for a bicycle, butâŚ
Has anyone heard of a pad adhesive? Seems like, on one level, another thing to blow more money on though. Would it make a differenceâŚ
Hah, I sweat a ton too. One of the first things I was told to do was use an iso wipe on the rotors âa lotâ. Some people swore by that one thing they did, and yet it did nothing for me. I mean, it doesnât do a thing to the pads for one, but it just didnât work, or on occasion last more than a ride. And with the tires throwing âcrapâ up, and the legs and shoes potentially redirecting it to the exposed rotor, it seems that fighting the squeal is a lost cause. (Why havenât bike manufacturers tried a rotor shield? Sure it would make a tire/wheel swap harder, but we put men on the moon so seems like someone should be able to make it work. (Just a random thought after spending so much time and money fighting brake squeal/honk)
More random: I guess I have been trying to treat brake squeal like I do chains. Wait until it gets bad enough and then replace the pads and then rotors if that doesnât work. I swear that the brass drill brush DID WORK. Until it didnât. I thought that it was âresurfacingâ the rotor and encouraging wear in the direction of motion, and exposing âvirginâ surface a little at a time, but I have one wheel pad/rotor pairing that STILL squeals after that, yet doing that has stopped it on other combos shrug Iâve gone through periods of desperation as I see the âcontaminated padsâ stacking up)
You should be installing with a pad spring that will keep them pressed back against the pistons.
For a car you shouldnât be gluing your pads to your calipers/pistonsâŚyou might use an anti-squeal compound that will help hold them in place (especially if they donât have clips/springs) and help reduce noise but shouldnât be glue.
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i basically ride everywhere I go. havenât had a car in a month and tried to not use the car before. iâm always on the road with this bike.
I have tried to bed them / break them in properly using a video on park tools for instructions
itâs not just a squeal like when it rainsâŚit sounds like a train emergency braking. like literally I even startle people in cars - pedestrians are basically ready to dive into the bushes - I feel so bad
thank you for all the suggestions. I do see that oil is leakingâŚi see spots on the backsides of the pads. I have bought 2 different calipers (plus the one that came with the bike). so I dunno if I got extremely unlucky or iâm installing them wrong somehow. The last two were the latest Dura-Ace models
my plan is:
- call shimano to see what they have to say
- buying the galfer rotors and pads
- calling around to find a bike shop that does facing
- gonna let them do a fresh install with new lines just everything from scratch
Interesting topic.
Currently my brakes squeal a lot, too. But when I initially got the bike it was absolutely fine. I think at some point the rotors are just too bent, and even bending them with the tool only helps (if I do it, theyâre fine for a bit but then the squeal comes back).
I will swap to powerstop rotors and pads soon, i am hoping that that will solve it for me, at least until that combo being new wears off, too.
just an update in case some searches for this in the future and itâs helpful to them.
I sent the calipers to shimano. you all were rightâŚthey are broken. they are sending me new ones.
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What was broken that makes them squeal?
As someone said much earlier in the thread 
yup! you nailed it.
thank you!
caliper seal was leaking a tiny amount.
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Brand new FatBoy. HONKED like it was headed south for the winter. I was spooking sleeping dear on forested trails (first days riding it)! I think they spooked me worse. Took it back to the shop. They âcalled Specializedâ who said to call Shimano who said call Specialized and get them to request a warranty for the pads and rotors.
New pads/rotors, and LBS says âStill honkingâ. Shimano sends replacements directly, honking gone. Two weeks later, honking back. Got new pads, honking gone. Didnât ride it for awhile. Week after honking again. Both give up. LBS sells me new pads. Honking gone. Back again in weeks. Iâve started cleaning the pads and rotors, with some improvement. Now I have a bin with 5 pairs of front/back pads (10 packs) and 2 sets of rotors.
I still have problems with my three other bikes too!
I really doubt that there is such a thing as rotors/pads that donât squeal! I mean like Iâd believe that chickens have teeth before Iâd believe someone selling âno-squealâ brake sets. Iâve tried iso, acetone, auto brake cleaner, DNA, just about everything but cooking the pads. The best thing that has worked is sanding the pads and using a brass drill brush on the rotors, and even that doesnât last long. Iâve given up.
I think if the rotors were thicker they wouldnât squeal as much. If the frames were filled with foam they wouldnât amplify the sound as much. If the manufacturers didnât make as much money trying to fix this issue as they do, it likely wouldnât be an issue anymore.
I had a client that made brake rotor machining tools that worked on larger brake rotors, and thought of asking them if they could make a smaller machine to do the same with bike rotors, but there again, those rotors are too damn thin! There isnât a lot of thickness to waste taking a meaningful/useful amount of metal off of them.
And telling people with bike racks and small cars that they are feeding the brake squeal racket isnât going to go over well.
Make the rotors thicker? Make a machine that can reliably resurface them. Figure out what to fill frames to eliminate the hollow spaces, yet not cost a lot in weight gain.
DO BETTER PADS!
I think that the industry could fix this, but they are making too much money off of people desperate to stop getting so much attention, or end up spending hundreds of dollars and hundreds of hours to deal with it. ARG!!
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Recently moved to BBBâs Powerstop and their organic pads. Not a lot of squealing. In the slightest of wet quite badly, but otherwise not much, and usually also disappears after a few hard brakes if it does happen.
Before I was on Shimano and that was hell, so much so that I thought the caliper must be leaking. But kept the caliper and just changed pads and rotors and it works really well.
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Do you ride your fat bike on the beach, whatever alloy Shimano use for their callipers is really susceptible to saltwater corrosion.
I had a set of Shimano Deore callipers on a bike I regularly rode on heavily gritted roads in winter and on the beach. The salt caused corrosion on the piston bores that roughened of the surface enough that they started weeping oil. I stripped the callipers, popped out the pistons, cleaned off the corrosion with some fine emery paper, and reassembled theyâve been leak free since.
I havenât had any leaking, so far, aside from a JagWire hose bursting in the down tube of that bike (surprised me for sure, never had that happen before. (Was the oil frozen in the tubing and that caused the rupture?))
I started my career of disc brakes with Elixr 7âs (from memory) that were actually pretty reliable. They only needed bleeding twice, and I was able to do that myself fairly easily. They didnât squawk or squeal much, but that model was widely rumored at the LBSâs to be involved in a âsilent recallâ. 
Never had any leaking or had to replace the rotors or pads. The rotors were solid steel (stainless?) and maybe had more mass to squawk/squeal? Iâve wondered if the âthin/lightâ Shimano rotors actually encourage obnoxious noises. They are light, and possibly/coincidentally tuned to induce those noises? (Is there a Center Lock solid steel rotor anywhere to test this hypothesis?)
The Shimano resin/organic pads did make a bit of difference with the brake sets I have, and those Elixrâs are the only non-Shimano disc brakes I own. Probably no coincidence that I honk/squawk/squeal so darn much? 
Just so tired of the drama, and tired of spending so much time/$$$ to deal with it.
Shimano >
I still do not understand why, but my road bikeâs Ultegra brakes squeel like crazy after the bike has been sitting for a while. Thereâs no leakage around the seals, nothing is touching the bike, and it doesnât squeal during the last ride before I put it away. But if it sits for a few weeks unused, like clockwork the brakes squeal when I use it again and it takes a solid cleaning of pads/rotors with alcohol to remedy. Iâve just accepted it as a fact of life at this point⌠there must be something in the Vermont air that doesnât agree with my resin pads.
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it could just be humidity. 
kind of like when you get in your car the morning after a rain and your brakes feel a bit different at firstâŚ
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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 thereâs probably something to do with the wheels and their weight/stiffness.
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