I'll take your word on that as i have no idea,just thought what a cool bike and load up the picture for you guys & girls
^^^^^^^ I may be wrong but I think that is the "Roarer" 500cc twin, in line 2 x contra rotating cranks, supercharged and shaft drive and SA rear suspension, c 1938
Just putting the finishing touches to bringing this back to it’s original spec Coburn and Hughes Black and Gold Le Mans 2 ... (Sorry for the poor phone pic)