Originally Posted by
AndreyT
You are absolutely right. Disc brakes are at mechanical disadvantage compared to rim brakes. Disc brakes have to compensate for that by generating more braking force between the disc and the pads, i.e. by exerting more clamping force. They do it. And they do it successfully.
Bicycle brake efficiency is capped by such objective limits as 1) wheel losing traction and beginning to skid, or 2) bicycle flipping over the front wheel. So, if your braking system can provide enough braking force to reach these objective limits, your braking system is obviously as efficient as any braking system can possibly be. Mechanical disc brakes easily reach these limits, which means that they are equally as effective as hydraulic ones.
The parameter that might differ here is not the efficiency, but rather the precision of the braking system, a.k.a. "modulation". Hydraulic brakes usually offer better modulation than mechanical ones.
Another parameter that might differ is heat resistance. Mechanical brakes usually resist overheating better than hydraulic ones.
I was getting ready to type out a response, but you said it better than I would have. I prefer mechanicals only because for me they are easier to work on. I have ridden rim brakes and various mechanical and hydraulic disc brakes. The only time I had an issue I couldn't resolve myself was with hydraulics.