Originally Posted by
colnago62
I looked up the definition of a disc brake on 5 sites. Your definition is not correct. None of the definitions said anything about the rotor having to only serve a single duty. If it uses pads pressed against a rotor to create friction to slow a vehicle down, it is a disc brake. The implementation may be different, but they both are still disc brakes.
Yes, by all means let's ignore the actual point I was making and split hairs over whether or not a caliper rim brake meets the most inclusive possible definition of a disc brake. Because making a big deal about how rim brakes are "actually" disc brakes really sheds a lot of light on the discussion.