Originally Posted by
BonkonFleet
I haven't read any posts on this thread except the last page, but just wanted to add that I own a disc brake Emonda sl6 and had a 2009 Madone before that (rim brake). After owning and riding both I can say that my next bike will be rim brake. Specifically a Canyon Ultimate cf slx 8.0 Di2. In my opinion disc brakes are great, but totally unneccessary for road bikes. They are heavier, more expensive, there is a 100% chance they will rub at some point and it will happen more than once, and in my opinion they look bad on a road bike. They do stop better than rim brakes though I guess.
^This....
....This is what makes the issue. Those of us with experience on disc will tell people that say this, "Oh the rubbing is fine it doesn't actually slow you down just makes a noise. Here let me press the pistons back for you and that will all go away. See."
but you can't tell a roadie that something making noise because of touching something rotating on a wheel is fine. It will drive a roadie nuts.
I have said this in a few places, including to engineers at SRAM and no one seems to be interested but road calipers need to be a dual acting system. Low pressure, fast/longer stoke in until contact, then switch to high pressure circuit for braking. Yes, I worked at a hydraulics company for years and spent more than my fair share of time making and designing hydraulic circuits but I totally forget how to achieve this but I believe it was just different reservoir/passage sizes and check/or weighted valves. This would allows road disc pads to retract and GTFO out of the way when not being used. It would stop pad rub as well.