Tom A. wrote:
AndyCaleb wrote:
I feel like this is something that should get mentioned more, when people talk about pros and cons of disc brakes. I would not have bought disc brakes if I had known they were so finicky. I really dislike riding a noisy bike. Am I the only one? Sorry for the rant, but just had to get it off my chest.
Oh, it gets mentioned...along with pointing out the tendency for them to also squeal more upon application...but those voices usually get shouted down, typically with accusations of Luddite-ism. :-/
In the end, the tight pad to rotor clearances required on hydraulic discs are the result of using a relatively small braking surface at a relatively small diameter, and with materials that aren't super "grabby" (relatively speaking)...all of which means that the piston forces need to be quite high for a given braking torque. Since the travel is basically defined by the piston seal rolling (and is pretty much linear) this means (combined with the high force required) that the piston travel distance is quite small. It's a leverage thing...you can trade off travel for force, and vice versa. On many vehicles (such as cars, motorcycles, etc.) the pads actually rub almost all the time...but, those aren't powered by mere fractional hp "engines", so the additional drag isn't really noticed...it just is what it is.
Oh yeah...I've found that one of the nice things about using cable actuated discs is you can adjust the pad clearance up or down as necessary. Sure, that also means you need to periodically adjust them for wear as well, but that's a pretty minor annoyance. Folks tend to say that the cable-actuated models don't perform nearly as well as hydraulic, but that's really only true when comparing to ones that only move one pad and rely on disc flex to press against the other (such as Avid BB7s, etc.) Set up with solid, link-type cable housings, the power transfer on dual sided actuation models (e.g. TRP Spyres) really doesn't give up much, if anything, to hydraulic actuation IMHO.
Lots of this... emphasis added. Discs brakes can work well in terms of the actual functioning (as can rim brakes), but in my experience they always require significantly more work and fiddling than rim brakes... and they always make more noise. I've run in to more than one disc supporter that just doesn't mind the noise. The biggest impediment to this entire discussion is that it's very nuanced... for both rim and disc brakes, the devil is in the details, and it's impossible to talk about in short generalizations (which doesn't go well in modern internet culture). I've written in many articles for several major publications about this... here are a couple:
https://www.slowtwitch.com/...r_-_Part_1_6977.html
https://www.slowtwitch.com/...r_-_Part_2_6982.html
I say this as someone who was really enthusiastic really early on discs... first for cyclocross, due to a lot of the awful canti brakes and flexy forks. With road, I was at the very first road disc press event for Shimano, and I was admittedly impressed with the feel and performance (though the best rim brakes are equal or near-equal). Years later, having a better understanding of the costs, I am a lot less enthusiastic about them. My day-to-day bike has rim brakes.