installed Corki resin brake pads

[handlebar]

After a year, the rear brake on my Radrunner failed. I had adjusted the cable but not the caliper because Radpower instructions made it sound difficult. The wear pattern showed that it had come from the factory offcenter and askew.

Corki offers resin, semi metallic, multi metallic, metal, and copper, in increasing order of heat dissipation and longevity. I ordered resin because they're supposed to be the quietest.

Installation was much easier than I'd been led to believe. I loosened the cable so that the lever on the caliper would open to the stop. I loosened the inboard pad adjustment so I'd have plenty of clearance. When I remounted the caliper, I left the screws loose enough for it to slide without much friction. I tightened the inboard adjustment to clamp the disk between the pads, so the disk would align the caliper. I backed it off enough for the wheel to turn freely.

I adjusted the slack out of the cable and applied the brake by lashing the brake lever to the handlebar. This would center the caliper for actual use. I tightened the screws. I untied the lever and the wheel turned freely.

After a couple of days, I noticed a little squeak, once per revolution, when I rolled backward out of the garage. Then I began to hear it rolling slowly forward. After a month, I looked into it. With a digital caliper, I found that the runout was 0.2mm. That doesn't sound like much, but the sector farthest outboard was the one squeaking. It must have been hitting the outboard pad. With a Knipex pliers wrench, I applied a little leverage to warp the disk flatter. I got the runout down to 0.1mm, but making adjustments just moved the squeak to another sector. Apparently warpage wasn't the problem.

I cleaned the disk, but the little squeak was still there. So I lashed the brake lever to the handlebar, loosened the caliper screws, and retightened. The squeak was gone. A day or two after installing the pads, I'd tightened the cable to compensate for break-in wear. Apparently this had left the pads just enough offcenter to squeak.

I hadn't noticed until I worked on the brake, but applying it produced a slight scraping noise like dragging cardboard, or a creaking like a vinyl saddle. I cleaned the pads with a Scotchbrite pad, then a paper towel dampened with contact cleaner. It made no difference. These pads are quiet but not silent like the OEM pads on the front.

[Radio Runner]

I spot Knipex. Love those. I have four in my collection.

[handlebar]

I spot Knipex. Love those. I have four in my collection.

It's hard to believe I spent so much for a pair of pliers, but I'm glad I did.