mounting a front brake disk on a old hub

[mwilliamson]

Can I mount a Shimano disc on an old mtb hub, or do I need to build a wheel with a new one?

[Quo Fan]

If the hub had a disc mount, then you can mount a disc on it. The new Shimano centerlock hubs look similar to non-disc hubs, but are not the same. Your frame must also have disc tabs to mount disc brakes.

[Matrimony]

Well hes talking about mounting a front disk brake, but anyway, all you have to do is make sure it has the 6 holes for a rotor, they aren't hard to spot, and also make sure your fork (if thats old as well) can accept disk brakes....you might also need a specific adapter..