The Place

Here goes - some if not all of the Honda road going twins dud not use the conventional twin crankshaft design where both conrod/piston assemblies go up and down together, i.e. the engine fires once for every 360° crankshaft rotation. They used a design where when one piston was at TDC the other was at BDC. Thus the engine fired once at TDC and then the other cylinder fired 540° later. The thinking was that such an arrangement reduces the natural vibrations inherent in a 'conventional ' parallel twin motor, it also made for the distinctive exhaust note in bikes such as the Honda 305cc CB77.

I believe that Alan built such a crankshaft in the latter '60s which, whilst probably reducing vibration, did little in the quest for more power from a readily available engine.

HTH - if anyone knows differently then please speak up

i think Bob might be talking 180deg, Alan always used 360deg.we are now using 180 and 90deg cranks,some call them 270deg Alans bike made the wrong noise for a 180 or a 90,he used 360 with a 2 into one exhaust, it howled. the noise from a180 or 90 is a much flatter and gruff sort of noise.the only person that i remember using a 180 in the 60's was Mick Rouell with an Norton Atlas engine,i remember him well as he had one leg which he had to stick out backwards also i beleive that Geoff Monty of Monty & Ward Made a 67deg cranked Triumph for their own use.Bob you are of course correct it was done mainly to help the vibration problens on 360deg cranks

Well, if it wasn't Alan then someone did, remember it clearly because the exhaust sounf stuck out from the pack like a sore thumb

The NSU is possibly Bob Pyetts