Originally Posted by
rydabent
You dont need too much common sense to see that the brake circle on a caliper brake rim runs 90 degrees to the wheel. That means that tire pressure has a surface to bow the rim out. A disc brake rim would be more aero, and run to the edge of the rim at an angle. There for the rim would contain the air pressure better and be stronger.
If the strength of the pressure vessel were in question, you might have a point although any noncylindrical pressure vessel isn't a good pressure vessel. But rim "strength" doesn't concern holding the pressure of the air in the tire. Even when pumped to really stupid pressures, rims seldom fail due to overpressuring. The rims that have had brake tracks fail on me...and there have only been a couple out of dozens of wheels... have all been low pressure mountain bike rims.
Rim "strength" is usually talked about in terms of weight carrying capacity. Hub mounted disc and rim brake rims are about the same strength there...not that the rim has all that much to do with wheel strength in the first place.
Originally Posted by
rydabent
It still remains now that we have disc brakes, it is just plain stupid to wear out a rim with caliper brakes. There are many instances of reports of cross country cyclist braking a rim due to wear. Broken rim equals cyclist on foot. OTOH if something went wrong with a disc brake, they could keep riding since they would still have a functioning brake..
If something goes wrong enough with any
brake...hub mounted disc or rim... to make the brake nonfunctional, the brake is non-functional. I think you mean if anything goes wrong with a disc brake
rim, you'd still have a functioning brake. But if anything goes wrong with the rim, you usually don't have a functional wheel which means a functioning brake is useless.