Originally Posted by
mechBgon
Holy crap! I would've taken a picture of that as well.
Originally Posted by
mechBgon
I've found no clear pattern on that one. If a customer has squeal issues, they're more likely to have organic pads than metal (Shimano organics are particularly prone to "the moans"), but it can go either way. I've also encountered a few customers whose bikes hit a vibration harmonic when braking, and the only solution is to change rotor sizes. Personally, I literally threw out my first disc brake because I couldn't get it to stop squealing and it was, frankly, embarrassing to ride in traffic like that. "What's he honking for?!"
This squeal with disc brakes is indeed an elusive one. Although my experience has been
less squeal with
organic brake pads.
Both my BB5s and BB7s will squeal a bit when wet, the BB5s more so. Both will quiet down with just some braking. Now I use XTR rotors on my BB7s, so I think the rotor quality, as well as the brake pad and caliper quality will matter quite a bit.
After having ridden on discs for awhile, I'm starting to be convinenced that the dirtier the rotor and brake pad, the less squeal.
I say that because when I first started using discs 6 years ago, I would routinely use rubbing alcohol to clean the rotor on the BB5s (my OCD). I had squealing issues like you wouldn't believe.
Then after talking to a mechanic who works at MEC, I tried just leaving the dang things alone, as he advised. You know what? The squeal was much less.
The mechanic stated that the commutting or road type bikes they sell with discs will show up back at the store within 3 months with the customer complaining about squeal. They'll rough up the brake pad and rotor, squeal goes away, only to return a few short weeks later.
Their mtb bikes, with disc brakes, do not show up back at the store nearly as often with squeal issues.
He thinks that the grit picked up when off-road cycling keeps the pads and rotors from becoming too smooth, you know that shiney look you get on brake pads (?), that is what he means and he feels that this is the cause of most of the squeal.
On road bicycles with discs, they do not pick up the same amount of grit, and those brakes will develop that issue on the pads.
So, I do not clean my rotors, and the squeal issue is mitigated considerably. Only occuring when wet, and then will dissipate quickly.
Just an observation.