Thats sounds easy enough. Will most likely be the way i go. Could you by chance point me to that adapter?This is how I did it. For the rear I bought a grubee hd hub and a disc brake rotor with an adapter that threads onto the hub, then I made some caliper mounts out of plate steel and welded them onto the frame. For the front I scored a MTB front wheel out of a dumpster with a disc rotor already on it and pretty much did the same for the rear for the caliper mount.
I also rigged up my brake lever so it pulls on both brakes at the same time.
Just curious... how did you mount the disc to the grubee hub?This is similar to what I got for my rear.
http://www.ebay.com/itm/New-Mountain-Road-Bicycle-Bike-Mechanical-Rear-Disc-Brake-Caliper-Set-Kit-Black-/221322722341?pt=US_Brakes&hash=item3387dcbc25