Originally Posted by shider
Why is this a problem? (In fact, it is very common practice from several manufacturers.) The other way around is a BIG problem; disk specific rims can NOT be used with rim brakes.
Some rims are intended for dual purposes....no problem there. But lightweight rims that have their weight in the braking surfaces may lack sufficient strength in the spoke bed. I have seen a Mavic 317 built into a disc wheel (against my advice) literally tear apart from a rider braking and turning at the same time.
Remember that disc brakes stress wheels very differently than rim brakes. Only the tire sidewall sees significant brake torque in a rim brake, but in disc wheels the braking force has to be transmitted through the spoked structure in order to function.