Squeeling brake pads and cleaning brake dust from wheels.
We've all heard the effects of dirty wheels and brake pads at one time or another, but how many of us can actually say we have noticed a degraded performance of non disc style brakes?
I've noticed that riding in this area I tend to spend a fair amount of time bringing myself to a stop with a fair amount of pressure on the brakes. I'm more of a fittness rider so my bike doesn't see nearly as much of the elements (unless it's on the roof...then it almost always rains) but I figured the commuters would have more experience with brake noise concerns.
It seems outside of some regular free play adjustment many people assume the brakes are working fine, if the pads are above the wear limit lines.
Over in the automotive world there have been many times where I have replaced a set of brakes and had people return saying the brakes are now too sensitive...in reality the degradation is so gradual that the diminished effect of the pads and friction surface is hard to notice. If you ride the same route frequently you will most likely notice an increase in stopping distance over time, I know I have. Whether that is the cheap pads I am running (factory Tektra, low to mid end) or my obsessive attention to little details like that the jury is still out.
I'm curious to see how many of you have noticed this and at what mileage you are maintaining the rims or replacing pads.
I'm about half way through a set of pads, I have just about 2500 miles on the road with them and they appear to be about half worn.
Stopping distance is fair but I've noticed an increase in required force to bring it to a stop down a hill. I know a fair portion of that is due to bringing my big a** to rest as well....damn you Newton
I feel like I am over maintaining this issue, but am curious what everyone else is doing about this.
About every hundred miles I use a scouring pad to clean the brake pad material off of the wheels (clincher Mavics). I always get a fair amount of dust and debris off of them and sand the pads with a finer grit sand paper to remove the wear lines. The brakes seem to improve in responsiveness for a while but fade back to just about where they were in a few days, the rims are always fine, never dished, cracked, or chipped and I plan to keep them that way (knocks on head)
How many people out there proactively replace pads because they annoy you?
I just use disc brakes and don't worry about wearing through my rims. They sometimes sound like all the demons of hell when first starting out wet, but that burns off fairly quickly.
The brake geometry changes with pad wear. It isn't like a disc brake where the pistons really move at the same angle/geometry as the pads wear or cables stretch. That can often have as much or more impact on brake performance. That totally depends on the brakes.
I have some fancy-pants carbon fiber brakes that lose much of their braking power when the pads reach half way to the wear line. I can adjust the cam to compensate, but I end up just changing the pads most of the time. It is expensive, but that's the price I pay for being a weight weiner.
The other thing to think about is that as your brake pads wear, the place that they hit the rim is different. With caliper brakes, the contact patch moves toward the tire. With cantilever brakes, the contact patch moves toward the spokes. Both are bad. You need to either replace your pads, or adjust where the pads contact the rim. Some linear pull brakes use a parallelogram linkage for the pads. That means the contact patch does NOT change as the pads wear. Shimano and Avid both made linear-pull brakes with this set-up. They were expensive, but often worth it.
Hope that helps a little. I think Nick Legan or Lennard Zinn did an article about this in Velo magazine recently. I'll see if I can find this.
Is that why my front brake sounds like a screaming banshee? I need to clean my rims?
I've gotta take the Tank over to the co-op this weekend anyway, my chain keeps falling off when I try to shift to the small chainring. But only on hills. :P
Many things cause brake squealing. Pad choice, dirty rims, worn rims, worn pads, pad alignment, brake linkage being loose or flexible and sometimes brake design. Most of the brakes that have chronic squealing problems based upon design are actually disc brakes.
Originally Posted by KelOnWheels
I'm very fortunate. My favorite disc brakes gobble like a turkey when I lay heavily into the brakes. I'd pay extra for that kind of functionality... but end up getting it for free with Formula KG24 disc brakes.
My second favorites are the carbon brakes on carbon rims which sound like the Starship Enterprise is launching a shuttle craft. I love the freaked out looks when people hear that for the first time.
Rock and roll.
The irony here is that you've got them on an old-school steel frame...
Originally Posted by Dirt
I hate the fact that the more expensive the wheel and brake combo the noisier they tend to be. The sound that wheels like Profile Designs full carbon wheels make when shifting and stopping would irritate me to no end but I am over the top when it comes to keeping everything shifting and braking silently. I'd probably stick with a heavier set of Cosmics.
It also occurs to me that my brake pads are 19 years old and probably ought to be replaced just on principle.
Originally Posted by Dirt
interesting. one of my bikes is squealing and even shuddering. the pads are new, the rims have been cleaned (including lightly sanded and wire-brushed), and i have attempted to toe-in the pads. (the brakes are old-style side pulls so there are no conical washers).
Originally Posted by Dirt
the bike is an old schwinn worldsport that i rescued from a dumpster. it has been completely disassembled, cleaned, regreased, and reassembled. the tires/tubes and brake cables are new. i wanted to convert it to a fixed gear, but it has a freehub, and is now a single speed.
so, could the pads i purchased be incorrect? (the bike tech at the store told me the pads were the right choice.)
ugh. I just bought my bike a little over a month ago, and the front brake (V-brakes) is squealing something awful if I apply any significant force to it. It's driving me crazy. I cleaned my rims, and that helped a little, but they're still squealing on more forceful stops. I should probably try to clean the brake pads myself before bothering the guys in the shop, right? Or should I just bring it to them (since all my maintenance is covered for the first year)?