is there a 12" disc set-up for a Commando

The current disc measures about 10 1/2". Does any one offer a 12"?
I have tried a new AN master cylinder. Though it gives a better feel when squeezing it I don't see a great improvement in stopping power.

RGM

At Andover Norton;

13.1678 disc adaptor for standard wheel

06.3849 disc - 11.5"

some additional fixtures & fittings will be required, no doubt AN could provide a complete kit of parts.

I have one of those discs on my Commando, it is a good upgrade. That and HH pads in a CP2696 caliper.