Further Thoughts on Brakes
My recent post on barrel adjusters received some terrific and thoughtful responses. I also received a couple of e-mail responses that indicate some riders really give brake set-up some thought. Each considered response let me know that I’ve got brothers out there for whom bike set-up is nothing to be left to chance—or a mechanic who doesn’t know your style of riding.
At some point, the alternate views on how to adjust brakes intersected with my memory of some photos I shot last summer as I was inspecting my bike at the end of the Route des Grandes Alpes. My point with this post isn’t, ultimately, to refute other views, but to give you another point to consider as you assemble a bike.
The image above might not make much sense on first glance. After all, it’s from the back of a fork and you really can’t see how the Red calipers are set up. So why is it here? Same reason the following photo is.
If you look closely, you can see scoring on the inside of the fork blades. When I first saw this it didn’t immediately make sense. Then I clamped the front wheel back in the dropouts and realized what I was seeing. The scoring was caused by the edge of the tire tread where it meets the casing. It resulted from open tubulars I ran, tires where the end of the tread has a squared-off edge.
So how did this happen? Let me begin by saying the blame does not lie with the shuttered Alpha Q fork line. The scoring was caused by low spoke-count front wheels. I’m a fairly predatory descender, though I’ll be the first to admit there are guys who’ll drop me like a high-school girlfriend. Those low spoke-count front wheels flex a bit and under hard cornering the wheels flexed enough that the edge of the tread just rubbed the inside of the fork blades. I took a flashlight and a magnifying glass to the marks just to check if there was damage to the carbon fiber. So far, the scoring has yet to penetrate below the clear coat.
What does this have to do with brake set up? Lots, in fact. If you run your brakes really close to the rims, wheel flex can cause the rims to rub the brake pads during either out-of-the-saddle efforts or hard cornering. While I never felt a braking effect in switchbacks, I’ve been able to hear a rim rub a brake and I can’t help but think I’m losing wattage with each pedal stroke. Worse, should I hit any sort of pothole or frost heave or other obstacle that knocks the wheel out of true, I’d need to open up the brake to keep the rim from rubbing. It’s not a huge deal on Shimano or SRAM brakes, but with Campy, opening up the brake lever isn’t something you file under advisable.
If you’re running Ksyriums or some other similar wheel that offers virtually no flex, go ahead and run those brakes close to the rim. Otherwise, consider these images and the possibility that a bit of lever throw might offer some advantages.