The (front) brakes on my S4RS have become very squeeky. It's only when it is coming to a stop. When braking normally there is only the standard sounds from the floating rotors. I haven't tried brake cleaner or anything and they look totally clean. I was wondering if maybe I got a little careless when cleaning the front rim. Would cleaners or polish make them squeak. They work just fine and I haven't noticed any degradation of the brakes performance. They also don't do it every single time only like 60/40 squeak/no squeak.
You could the remove the pads, sand, reinstall and clean the rotors with brake cleaner drill, but if they work well and the squeak isn't too bad I would just ride.
I'll try some brake cleaner but Im not sanding the pads. I don't know why the heck they squeak some days and not others or why they squeak at all for that matter. As long as they stop like a MoFo It's all good.
Its not sanding the whole pads...its the edges.
If you are really bothered by it (like me) you either have to take em out and sand in the edge of the pad that touches the disk first and create a ramp.
Also you can use liquid copper to even them out more.
Or you just buy new ones that come like that.
Anyway...its the disks that are set into motion and produce high resonant vibrations. [coffee]
Good luck
QuoteWHERE BRAKE NOISE COMES FROM
Brake squeal is caused by high frequency vibrations. When the brakes are applied and the pads contact the rotors, tiny surface irregularities in the rotors act like speed bumps causing the pads to jump and skip as they scrape against the rotors. This, in turn, causes the pads to shake and vibrate in the calipers and against the caliper pistons. It also causes the calipers to shake and vibrate on their mounts and bushings. The greater the play between all of these parts, the greater the amplitude of the vibrations and the louder the squeal. The rhythmic vibrations of the pads rubbing against the rotors also creates harmonic vibrations in the rotors that causes them to ring like a cymbal. The areas generating the most noise can be seen with special laboratory equipment that uses a laser to scan the surface. Changes in color reveal the intensity and frequency of the vibrations. Researchers have found that rotor vibrations are not uniform all the way around a noisy rotor. The rotor has certain spots or "nodes" that oscillate more than other areas. By redesigning the casting and changing the location of the cooling fins between the rotor faces, some of this noise can be tuned out (a good reason to use replacement rotors that have the same cooling configuration as the original!).
squeaking is usually the pads moving slightly against the pucks, which is why you use lube to assemble them. it sounds like yours might have worn out (the lube).
i would take the pads out and use a sander on them (the hand orbital kind, very cheap to buy) with a fine grit sandpaper. if you do it by hand, you'll make the surfact uneven, so use a sander. you won't need to run the sander more than 10-20 seconds
then clean off the backs, squeeze the pucks back into the caliper, put brake lube on the back, put them in the caliper and assemble the clips and squeeze the calipers and hold them for a while to set the lube.
sanding the pads alone might fix things. yes, you'll need to re-set the surface but the end result is your brakes will work better and be quiet.
which is why you use lube to assemble them
Reminds me of a friend, not very mechanically adept, who "lubed" his bikes brakes. Coming down a steep, long hill that T' ed into a major, very busy four lane, he said that when he slammed on the brakes the bike left like it actually sped up . ;D
I'm amazed he's still alive and that brakes don't squeal all the time, considering what they do. [roll]
I recommend riding the bike really hard for a couple of hours and using the brakes really hard and if that doesn't fix it, go to a bar a have a few Guinness and think about it. [drink]
No, it probably won't fix the problem, but it always makes me feel better when I don't know what to do about something.
LA