i think its a custom clutch that uses weights to clamp. so when the bike slows/stops the weights move and the clutch disengages, clutch only needed for neeutral to first shifts

Frank

(Former)05 BA tbike pipes, ai removed, Freak, mikuni hsr 42's, 904, ported/polished head, 1mm oversized valves NOW-2010 silver and black tbird