That's a clever one, well spotted Prutser
and thanks for all the advice, I owe ya one.
I've decided to go with a tubed rim, I just cant find an 18" rim for reasonable money. I'll give central wheels a shout to see
about the cost of offsetting the rim on my 1100GS hub. Apart from positioning the rear brake master cylinder and fitting
an 18" Enduro tyre to the back I'll be done.