I just started a thread asking for help choosing a folder with disc brakes for daily commuting. There were a number of responses questioning my "need' for discs; I'd like to keep the other thread confined to the original topic, so I'm opening a discussion here to debate the actual merits of different braking systems on folders. I got a lot of interesting responses, and I do want to respond to them because although my experiences give me a pretty solid belief in discs for wet weather, I do think it's a conversation worth having.
So is there something about 20" wheels, or folding bikes generally, that makes rim brakes work better than on bigger-wheeled bikes?Originally Posted by GlowBoy
A little background on my experiences and how in the past I have not found rim brakes to be acceptable for my commute. In the early 2000s I used to ride a cyclocross bike; but I upgraded it to V brakes (with 287v levers) when I found the Avid Shortys just weren't up to the job. Big improvement, and they worked great in the rain -- as long as the rims were clean and the pads weren't glazed. Problem is, after a week or two of riding in the rain my braking performance would diminish. A LOT. In a panic stop I'd grab a handful of brake and have to wait a second or two -- a couple of wheel revolutions -- before I'd have enough braking power to lock the wheels. When I'm rocketing down a hill at 50 ft/sec, or cruising downtown and panic stopping from 25 ft/sec for some idiot who pulls out in front of me, that is unacceptable. I could restore full braking performance by scrubbing down and cleaning the rims and pads, but having to do that once every few days is not acceptable either.
The other problem was pad glazing. Even with the ridiculous maintenance task of regular rim cleaning, after a few weeks of riding down 1000' hills I'd find the pads glazing up, and to restore full braking I would have to attack the pads with a file to remove the crud. And that was with red or blue Ritchey pads -- the problem was even worse with harder pads.
I converted to discs for commuting more than 6 years ago, and I haven't looked back. They solved all of my problems: maximum braking is instantly available in any conditions with a single finger on the lever. Disc brakes have become standard equipment on nearly every dedicated commuter bike above the $1000 price point or so, and that price cutoff is dropping steadily; that's been particularly true in this bike-crazy town where discs have particular advantages. While the bike industry is highly susceptible to profit-generating fads, I've been pretty well convinced by my own experiences that this particular trend is functionally justified.
To those of you who are commuting in rainy, hilly urban environments with rim brakes: what's your magic bullet? How do you keep rim brakes working well enough for optimal safety? Or is there something about the physics small wheels that makes rim brakes work better? Or are caliper brakes such as on the Brompton that much better than Vs? Or is it just that disc brakes another thing like the Internet or smart phones or quality beer -- if you've never experienced it you don't really know what you're missing, but once you have had it you'll never go back?