The unit single Triumph is a BSA engine. The pre unit engines are even more caveman than the "modern" Brit engines. I've stuffed a couple into more modern frames & they are cool, but they are what they are. You will have a push rod engine with 2 valves, and a right side shifting 4 speed tranny with a kinda weak 2nd gear. Also there is no balancer shaft, so it can only be tuned vibe wise to one RPM.... not something for a long road haul. I've also put an A65 twin into a Yami frame.... looked way kool, but again... too heavy for the power it produces, etc.
Why waste a great frame on that? I really think a light 500/650 twin is a worthy direction to go in. There is nothing like that in the US, and there is an abundance of top flight singles already made in that range.
Beezer screwed with this post 04-27-2009 at 06:16 PM