Formula made hubs also, and there were adapters to take front 6-bolt ISO hubs to the 3-bolt front rotor BCD (which was larger), the rear 3-bolt pattern had an identical circle as 6-bolt ISO (so 3-bolt Amp/RS rear rotors fit 6-bolt ISO hubs). Chris King offered adapters for their universal disc hubs also as did Ringle. The calipers were designed around CANTILEVER compatible brake levers. They work well with road dual control levers as well. They sucked with V-brake levers which unfortunetly a lot of people tried to use them with, especially given that Rockshox started offering their version in 1998 when hardly anybody was producing quality canti-only levers anymore. EBC made pads for them in all three of their color compounds (green - general purpose, red - wetter conditions, and gold - race only). Pad choice makes a difference in performance. The rotors were 163mm front and about 145mm back but there was also a 7 1/2" diameter DH front rotor. I still have a dozen of the rockshox calipers, half of which are NOS and I'll eventually put them on ebay. They're still a good brake for CX bikes and road bikes since they're compatible with road drop levers and dual-control levers.