New to disc brakes; been riding a new bike for about 7 months (with a lay-up over last winter) that has 'em.

The brakes are Hayes CX Expert with semi-metallic pads. All riding so far has been on-road and without load. (Touring bike.) Back brake works fine, but front has taken to squealing when I apply pressure quickly. Doesn't if I feather in. Also the rotor sometimes "jingles" or "dings" on release, especially if I'm turning at the time. Still seems to brake just fine; just loud.

The pads aren't rubbing, and I've thoroughly cleaned both braking surfaces of the rotor with alcohol. Might have lowered the volume of squealing, but hasn't stopped it. Checked all the mounting bolts; everything's tight.

I've Googled and YouTubed this problem but haven't found anything exactly like it yet.

Haven't stripped or adjusted anything, pending forum input; since I'm new to the technology, I'd rather know what I'm looking for before I start scattering parts.

Thanks in advance.

probably a too-smooth disc... typically known as "glazed" or "burnished"..... the pads grab/release repeatedly, setting up a rapid vibration we can hear...

lightly sand the disc braking surface, and the pads, too... i use 180 grit black emery paper....

Remove pads sand paper * as above, face up on a flat surface.. remove glazing on surface.

I chose coarser 100 grit ..

No, it can't be! Disc brakes don't squeal like cantilevers, that's been advertised as a major benefit of discs for years now! Surely the manufacturers haven't been lying to us?!

Thanks for the hints; I'll check that out.

Can't speak to disc brake propaganda; mine howls like the Hound of the Baskervilles, in a way no rim brake on former bikes has ever done

even in perfect working order, they still make noises... did the sanding job get rid of that annoying as hell squeal?

OR... let it continue squealing, and scare the heck outta kids on bike trails... ;-D

Haven't had a chance to break those front brakes down yet and spend all that time trying to make them function, but...

1. Now the rear break is squealing, and what's worse:

2. I took my front wheel off to lock up to a public rack today, you know, like bikers do once or twice in their lives... and now the front rotor scrapes... scrapes... scrapes... . Unless I force the wheel into the dropouts crooked. (It was chucked up straight before. Any component that fragile has no place on a touring bike.)

In my opinion, disc brakes are a disaster, at least on a road bike. They're hard to instal, hard to adjust, don't do anything important cantilevers don't do, and jump out of adjustment -- which takes hours -- at the least provocation. They leave you no side to lay your bike down: derailleur on one, rotors on the other. Rotors that potato-chip if you stare at them too hard.

There's just no call for all this falderal; you set up your cantilevers, you ride. If anything goes wrong with them (and what would? it's a cable that pulls two pads against the rim) you see it and know how to fix it. They're sure not louder than disc brakes, and -- something I just learned -- just as good in the wet.

I wish I hadn't fallen for the sales pitch. Sigh. But I guess I'm stuck now, so you'll see me around here, trying to keep this boondoggle on the road.

Ding ding ding.

Glad you figured it out.

My advice, next time you set it up put the quick release on WAY tighter than you usually would. It helped me.

Disk brakes aren't too bad if you have a thru axle. They're awful with QRs.

I love having my retro-grouchery confirmed. I'm safe for a few more years

Persist with your discs. I don't believe most of the propaganda, but they're past the disaster stage.

Thanks, Corrado33. Wish I'd figured it out before I bought the bike. I guess I have no choice but to become an expert at 8-track brakes. Hope they still sell the parts after everybody else abandons them. (I'm from the 70s. I know this by heart.)

By thru-axle, do you mean just ditching the quick-robbery skewer and replacing it with a threaded one, or getting a wheel specially built for the heavier old-school axle? I was told you can't put one of those through a QR hub.

I've been wanting to get rid of the QRs anyway. Who needs to get a bike wheel off that fast, except thieves and racers?

I was talking about one of the even newer fangled "threaded" quick releases aka "thru axles". An old school threaded axle wouldn't work any better than a quick release. The problem is that both quick releases and old school threaded axles have no positional certainty in the dropout. You can put the wheel in in an large amount of different angles and positions. Thru axles, seen below, solve that problem to an extent. It forces the wheel to be in a certain position better than the old technologies do. That way your rotor and caliper can't get misaligned as easily.

EDIT: Unsure if the pic is correct, but it's close enough, you get the idea.

EDIT2: Your bike will never be able to use such a product. You'd need different dropouts. And new wheels. You could probably still mount rim brakes if you wanted to, I'm sure the fork is drilled for it. You may have disk only rims though so... yeah.