Originally Posted by
WhyFi
Oh, is that was the 105% refers to? Doesn't that really depend on the external width, too, though?
Yes it does.
The 56mm LB hoops are 30mm wide(23mm internal), so that 25mm tire becomes an actual 28.2mm when inflated. The hoop is supposed to be a touch wider than the tire for the 105% aero rule.