Bicycle Mechanics - Ceramic brake pad cause damage to alum rims?

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chajmahal
02-20-06, 01:01 PM
I bought a used road bike with Mavic aluminum rims and Gigapower ceramic brake pads model GB-355. The rims and pads were new with no marks or wear. The previous owner had just overhauled the bike and spend some coin but then had an injury.

After a few rides I noticed the braking had gone all to h3ll and the pads made an odd scraping/grinding noise on the rims. I took the wheel off and was about to sand the glaze off the pads and noticed shiny little aluminum flakes embedded in the pads. I picked them out with the point of a push pin, slapped the wheels back on and then after a few rides the same thing happened. Little aluminum flakes embedded in pads causing weird noise and poor braking.

At this point I noticed that the rim had accelerated wear to the surface and what looks like the same aluminum flakes stuck on the surface of the rim. Like they were scraped off and then deposited elsewhere along the rim. I looked on the manf website http://www.giga-power.com/road_and_band_product.htm and found the pads and that they are indeed meant for aluminum rims. On the Q&A page I found this:
Q: There are some particles, like aluminum flakes, sticking to the rubber compound. Does this mean that the rubber damages the rim??
A: Under normal circumstances, the rim eventually will wear out by any kinds of material. But if the brake pads contain metal they will wear out faster. Our compound contains no metal so it will cause less damage to the rim. A lot of our customer’s rims are produced by join pin method, the aluminum flake accrue when the surface of joint area isn’t smooth and after the pad goes past that area the aluminum flakes stick into the rubber. This can happen with any brand of brake pads. Consumers need to remove dirt, rocks, or other material that may stick in the rubber during the ride to ensure the quality of rim and proper use of the brake pads and system.

Anybody have an experience with this brand? Or experience with something similar in another type of ceramic or other compound pad?


HillRider
02-20-06, 02:37 PM
Brake pads intended for ceramic coated rims are death on regular uncoated alloy rims. Get rid of them QUICK!

When Shimano first introduced Dura Ace "cartridge type" brake pad holders they came with pads intended for ceramic rims and these very quickly developed a reputation for being extremely distructive to plain Al rims. Shimano made a design change almost immediately and there were warnings all over the various bike forums about how to identify and avoid these pads.