There seems to be a trend forming within the cycling industry to put disc brakes on every bike that exists. New road bikes with disc brakes are showing up in magazines and touted for their ground breaking technology. I’m wondering why.
I used cantilevers, linear pull, and finally disc brakes on my mountains bikes over the last 15 years. Each progressive step proving to be a bit better for mountain biking. Cantilevers had good power, but were hard to keep tuned, linear pull had even better power and were a bit easier to tune and use, disc have crazy power and are the easiest to set up. Another big benefit, when you bend a rim your brake isn’t effected, also mud and water, which is frequently encountered mountain biking doesn’t effect the brakes nearly as much. Probably the biggest improvement was an end to wearing holes in my rim’s braking channels.
So yes, disc brakes for mountain bikes are a big improvment, but how do they immprove road bikes.
Power: I don’t think there has ever been a time when I wanted more braking power on my road bike. Even weighing 275 and riding in Colorado mountains I had plenty of stopping power, now I’m not an aggresive descender, maybe if I demanded more out of my brakes?
Modulation: Disc brakes have great modulation, but so do all descent road calipers.
Installation: I’d much rather deal with road bike calipers then disc brake callipers and rotors.
All weather: I could see this one maybe, wet road calipers don’t grab so well when they are wet, of course I probably ride my road bike a handful of times in the wet. Still if I did alot of wet condition riding I’d see that as a benefit.
Wear and tear: I’ve never worn the braking surfaces out on any road bike wheel I’ve owned.
Road calipers major weakness is tire size, so cyclocross and touring bikes have traditionally used cantilevers. I’d probably prefer disc brakes in that situation.
One thing I haven’t considered is carbon wheels, I know they don’t stop as well as aluminum, I guess if you’re crazy enough to run carbon wheels you might want some disc brakes.
Finally, there is only one time when I thought I’d be in trouble because of brakes. I took my mountain bike to Gatlinburg and was riding the insane mountain roads near our cabin. After 45 minutes of 3 mph 30% climbing I turned around. As I approached a switchback I engaged the binders and my bike stated slowing down. Then I smelled smoke. My front disc was literally smoking and soon it was losing power. I released the front brake and locked up the rear. After a second I started pumping the front brake and it worked at about 50% power, but I got slowed down enough to make the curve. I stopped and saw my front disc was glowing orange.
I hope they’ve worked this out on road bike discs.