Rear thumb brake - diameter of standard forks?


New Member
Hi All

I work over seas so don't have access to my RC390 right now, but im looking to order a rear thumb break for when I get back home, have a track day 3 days after I arrive.

could someone help me out by measuring the diameter of the top of the fork leg, just below the top yoke ? so that I can order the right size bracket ?

im 6'3" and have size monster feet, and often struggle on rights at my favourite track (Cadwell park , UK) hence my shift to a thumb brake.

any advice would be much appreciated

planning on running a HEL rear thumb break and a DISCACCIATI dual port rear cylinder.