Possible silly question - Is the brake mount on a fork usually rated for any size disk - like you could put a 203mm on a sid if you wanted? Case at hand is actually a reba (100mm travel) and a big disk.
Leaving aside questions of why you would want to do this, I was just wondering if the mounting was strong enough by miles to take the braking forces, or if there might in fact be a risk of cracking over time.
I have cracked the rear hub flange holding a big disk after a couple of years, so was thinking along the same lines.

