Somehow I've never seen one of these before, looks like a nifty piece of kit.

http://www.ebay.co.uk/itm/2307352556...84.m1436.l2649

It has the slight inconvenience of mounting a tie bar, but as far as I can tell, no matter how skewed your mounting is, it can't fail to put you on the spindle rotation axis.

I'd buy one now if only it wasn't so blooming tall :whistling: