I am looking for new wheels for an old mountain bike that will be used only on the road.
Cambria sells a pair that says that it is both rim and disc compatable. Since I will only be using rim brakes, is there any disadvantage to having one that is also disc compatable?

Thanks

I am looking for new wheels for an old mountain bike that will be used only on the road.
Cambria sells a pair that says that it is both rim and disc compatable. Since I will only be using rim brakes, is there any disadvantage to having one that is also disc compatable?

No, no major disadvantage to using disc compatible wheels with rim brakes. Making a wheel disc compatible only requires that the hubs have rotor mounts (meaning the left flanges have bolt holes to bolt on a disc brake rotor). Oh, and the front wheel has to be cross-laced (not radially laced). The rotor mount adds a small amount of weight to the hubs, and there is no real advantage to radial lacing anyway. For this project, it sounds like a few extra grams on the hubs won't be a make-or-break thing, so the disc hubs won't hurt, but will add extra flexibility if you move them to a disc brake bike in the future.

**Another small difference is that front disc brake hubs have a small amount of dish, which will decrease the lateral strength/stiffness slightly. But front wheels generally have good lateral strength/stiffness already, so as long as it uses a stout rim and plenty of spokes, the dishing should be insignificant.