Originally Posted by Biker395

It doesn't seem like a lot because it isn't a lot ... completely overwhelmed by other things that influence stopping distance.

I just got off the phone with a buddy of mine who crashed on his tandem this weekend. And knowing the road he was descending (very, very steep and winding), it could have been much, much worse. How did he crash? His brake failed ... a disc brake.

He's a pretty competent mechanic, but had someone else working on his brakes for him, because like any disc brake, they're not as simple as rim brakes to adjust and figure out. So one could argue that at the heart of the matter, his crash would not have happened but for the disc brakes.

I'm not raising this because I think that disc brakes are any more of less prone to failure than rim brakes. I also know someone who had his carbon rim delaminate going down another nasty descent ... and that wouldn't have happened with a disc brake (the rim brake contributed to the rapid failure of the wheel). And tire failures are a possibility with rim brakes if the pads are not adjusted properly. Seen that too.

But anecdotes are just anecdotes. And there are a lot of factors that go into how well you can stop at any given time, and the risk of failure.

I would use discs on a tandem or on an MTB, because IMHO, their advantages outweigh the disadvantages in those applications. Not so much a road bike. If they can figure out a way to modulate fore/aft braking power (easier with a hydraulic disc system, I would think), I might be convinced otherwise.