Regarding axial runout, the only thing that could affect that is a variation in the thickness of the steel plate they start with. In the steel industry, variations across 205mm would measure in the tenths of a thousanths of an inch. In other words, virtually impossible with the design.
Radial runout is the only other error that could show up. Since they are probably done on some kind of CNC machine all in the same setup, the likelyhood of a radial error is also remote. Maybe Darren D will comment on this since he plays with that type of machine all the time.
I know Darren K ran them for a while when he had fake BRMs. No troubles. I think Lanny did too. I've never heard of anyone finding any problem with those steel adapters.
Whatever you buy, I would recommend staying away from the AC Industries wide 5 kit. That one piece solid CAST IRON rotor is so massive, it's like adding a flywheel behind your wheels.
The CB kit uses a cast aluminum hub with an iron rotor bolted onto it. Much less weight.
