<jerrymoos@sbcglobal.net> wrote:
> I recall that at the time the supposed advantage of centerpulls was that they "centered" better. That is, because the brake cable pulled from the middle, both pads would contact the rim more or less at once, while on a sidepull, one pad would contact the rim before the other side began to tighten in. Campy was touted as the first sidepull to stay properly centered.
>
> In reality, I've found that the Universal Super 68 SP's stay centered as well as Campy NR, although the Campys are undoubted a whole lot prettier. The difference between CP's and the old sidepulls may also have been exaggeratted, along with the real importance of centering. After all, at least in racing, if you're hitting your brakes all that frequently, you'll end up off the back of the peleton anyway. I read somewhere many years ago that the real reason for the switch to CP's was that Jacque Anquetil was using MAFAC CP's, and the reason for the switch back to SP's was that Eddy Merckx used Campy SP's. Probably a lot of truth to that.
Yeah, it's mostly a fashion thing I think. CPs, like modern dual pivots, have more mechanical leverage at the caliper, but must pull more cable as a result, often meaning that the levers have commensurately less leverage as a result. The more combined mechanical leverage you want the closer to the rims it is necessary to set up the pads all else being equal, meaning that centering and a true rim becomes that much more critical. I find that vintage CPs like Mafacs, Weinmanns and Universals as well as vintage SPs all work fine if set up carefully and with good fresh pads. I think most of the advantage of modern brakes is down to improved pad materials, SLR-type sprung levers, and much better cable housings/linings. Better bearings in lieu of the old cheap bushings once common that tended to bind under thrust loads probably also help "feel" if not ultimate stopping performance. One variable I haven't explored much is rim surface treatment or lack thereof. Is there any sort of consensus on whether rim anodizing is on balance helpful or not to braking performance? I never noticed much difference in braking as I wore through the anodizing on rims, although I never liked the look of rims with the anodizing roughly abraded off.
I do like the crisp feel of modern DP-type brakes when well set up on the front wheel, particularly when actuating them from the hoods. On the back they seem touchy and too prone to lock-up, although that may be because I'm simply too used to old Campagnolo Record SPs. I miss the old caliper QR eccentrics too, but not the infamous MAFAC screeeeeech (however useful for warning pedestrians) or crudely adjusting toe-in with an adjustable wrench by bending the caliper arms. Old brakes are generally less finicky about set-up and will tolerate slightly wobbly wheels which I consider pretty big plusses.
Kurt Sperry
Bellingham WA