I have two bikes at the moment (Giant XtC SE3 with marz AM3's and big 8inch rotor disc brakes 'the name of them evades me', and a Specialized P1 All mountain, with Marz AM SL's and AvidJuicy Carbons etc) and im jonesing for a full susser Kona so no doubt ill soon have another bike floating about with 8inch rotor on the front.

I use my two bikes quite a lot and have several different roads, trails, downhill tracks etc around here that allow me to get a good mix of riding. One thing is though im really wanting to have the ability to switch around wheels, so i can have a set of wheels from the xtc with semi slicks, and the rims on the specialized with burly 2.4 mud pluggers because i hate changing tyres before a ride. Only problem is the avid's have a 6inch rotor on the front, so i need a new disc and an adapter presumably to be able to run the same wheels on each bike. Do they sell adapters for such a conversion? Ive checked all the websites in the uk and turned up nothing.

Thanks.