The system seemed similar to that of Vincent and some pre-Second World War Matchless machines but had the benefit of more understanding of how suspension worked. Where the Vincent version transmitted load to the very short backbone of the Series D machines, Yamaha’s version put the load at the steering head. Benefits of this include no frame twisting and the possibility of having a longer suspension unit that can run cooler and not suffer from damping fade.
A triangulated pivoting fork is also stiffer and can be lighter without any flexing which gives a stiffer frame and thus more feel to the rider. Technical editor in The MotorCycle, Vic Willoughby, speculated on the details of this system before Yamaha released any information. Hindsight shows Willoughby’s educated guessing to be fairly accurate with his assumptions of inert gases being used to control damping. 
Enjoy more Old Bike Mart reading every month.
Click here to subscribe & save.
