Loud Disc Brakes

As a longtime user of Avid discs, I’d say you’re more likely to have a problem when they are being quiet.

@Steve 78368 wrote:

During these cold days, sometimes my disc brakes (Avid BB7s) are really loud. I removed the brake pads and cleaned inside to make sure it wasn’t road crud inside the brake assembly, but then again today it was super loud at times. It seems like if I’ve been braking a lot, the noise is less (perhaps because it is warmer).

Most brake rotors will start getting some surface corrosion pretty quickly, especially in this kind of weather. If you stop hard a few times and get the rotors polished to a shine they should quiet down. (Or, more than a few times. I had one bike garaged for a month or two and then went out for a ride with the kids–drove them nuts as I kept hammering the brakes like a dying goose until they were cleaned off.) The same thing happens on automobile or train brakes, but there’s so much more force involved that the crud burns off almost instantly.

Edit to add: the above is for dry brakes. Wet rotors will be louder until they dry, which takes a while in the rain.

@mstone 78375 wrote:

had one bike garaged for a month or two and then went out for a ride with the kids–drove them nuts as I kept hammering the brakes like a dying goose until they were cleaned off.

Now I’m imagining all the things our kids would write if they had a forum like this to gripe on…

@Tim Kelley 78372 wrote:

My disc brakes get loud when they are wet.

It gives the pedestrians in the crosswalk a heads up that you’re coming!

Loud brakes = feature, not bug.

The cantilevers on my cross bike make an ungodly racket. Just the way I like it.

@hozn 78377 wrote:

My disc brakes are really loud when wet. Sometimes it’s embarrassing when I terrify a pedestrian by lightly braking.

@Tim Kelley 78372 wrote:

My disc brakes get loud when they are wet.

It gives the pedestrians in the crosswalk a heads up that you’re coming!

@mstone 78375 wrote:

Edit to add: the above is for dry brakes. Wet rotors will be louder until they dry, which takes a while in the rain.

Everybody keeps saying this. My disc brakes are loud and squealy when dry and generally nice and quiet when wet. :confused::confused:

(btw, startling pedestrians is fine, but i find mine even more useful for giving the kamikaze squirrells due notice.)

as mentioned earlier in the thread, ponying up for some sintered metal pads will probably alleviate quite a bit of brake squawk, but to the detriment of the rotors.

general observation: Avid rotors are typically kinda crummy, but they’re relatively inexpensive.

Usually, noisy (organic pad material) brakes indicate some fouling of either the rotor or the pads. First thing to check is to make sure there’s no debris stuck in the pads – if there are tiny chunks of anything stuck in the pads, use a pin to pick them out. Another trick is to go down to the car parts store and pick up a can of brake cleaner (and get the not-so-safe for the environment stuff. the “safe” stuff is junk and despite the label, it isn’t “safe” for anything… also, don’t waste your money on any “bicycle” brake cleaner, it’s hugely overpriced). With the wheels off the bike, spray down both sides of the rotor, and keep a shop rag over the hub so as to NOT spray the bearings. Then, carefully give a couple squirts of brake cleaner on the pads and let everything evaporate.

Pop the wheels back in the bike and take it for a spin. you’re going to want to “bed” the pads to the rotor by getting some heat into both the pads and rotor. you’ll do this by either doing several hard stops from speed, or finding a big long hill and constantly, lightly brake. what’s going on here is that some of the pad material is going to stick to the rotor and some of the rotor is going to stick to the pads. when some crud gets on the rotor (especially anything with any kind of petroleum base, i.e., oil or grease) or the rotor is sparkly clean, the pads/rotor are going to make noise. Once there’s a good amount of pad material that’s transferred to the rotor, you’re usually gonna get nice and quiet brakes. However, it only takes splashing through a puddle or two to wash some of that pad material off, and get some crud on the rotor. None of that will really negatively affect the power of the brakes, but it will make them noisier.

Pro Tip: a quick way to clean your rotors and get some pad material back on the rotors (while you’re riding) is to take your water bottle and squirt some water (NOT PURPLE SPORTS DRANK) at the caliper, while you’re applying some pressure to the brakes. then, keep applying light pressure until the water has evaporated due to heat.