Thursday, January 16, 2020

Honda RC181 500

Motovue


Mike Hailwood's 500 racer of 1966 and '67 was apparently a diabolical handler and the standard frame with stressed engine was blamed. Wondering what makes a frame "bad" or "good",  I looked for pictures of that frame, the best I could find are the two conflicting images above, one with no bottom rail and another with a bolt-on lower frame rail, mostly unattached. Below is the first attempt, a small-diameter-tube Colin Lyster frame.

That apparently was not the answer, and Ken Sprayson of Reynolds built the one below.  Apparently the odd arrangement of tubes below the swingarm pivot was to accommodate the oil drain plug which was on the back wall of the crankcase. 
As always, the more I find out, the more questions I have. The book "The Frame Man" by Ken Sprayson should provide more answers. I'll put it on the list.




4 comments:

VectorWarbirds said...

If I recollect correctly Sprayson and Reynolds were also responsible for the frame for the BSA Rocket 3 racing program. I also remember that the team had a frame welder at every event. They cracked a lot but thats typical of road racing frames back then. I think the Honda frame was cracking as well and once they do they get kind of wobbly and can go into wobbly mode.

JP said...

For an education on the principles of chassis design, Tony Foale is perhaps
the most widely recognized expert. See https://motochassis.com/.
John Bradley's book "The Racing Motorcycle" is also very detailed.

Mister G said...

Tony Foale's book, John Robinson, Kevin Cameron and the [MC-CHASSIS-DESIGN] list. Much modern knowledge there.

Briracer said...

I was going to get that book out and look to see if there were any references.