British twins & vibration, smoothing them out!

[johnnyboy-wonder57]

Interesting article here, about changing the degree of crank pin location, to provide a relatively inexpensive  cure our industries big parallel twins!
http://www.xs650.org.au/smoothness.htm

Cheers

John


JBW

[R]

There are of course quite a few of those 76 degree cranks now around for various engines, and a few 90 degree ones.
A Norton owner with the 76 degree crank said it was smoother down lower, but vibrated like a rough 4 up higher. = fail.
Back to 360 degrees. (Lighter pistons make a difference).

The sidecar boys reportedly love them, more jump out of the corners.

P.S. Twisting a cam to suit must be interesting...