Originally Posted by sas

Thanks for the compliment Rick.

The gearbox has standard ratios with a 3.5 final drive on 205 40 16 tyres.

The basic revability of an engine is defined by its bore to stroke ratio.

The YB lump has a larger bore than stroke so it can rev harder

A bike engine is even more revable, even bigger bore to stroke

The ZVH 2.0 like mine 85mm bore 88mm stroke

But you can influance the power band with the cam timing. I was at almost 7000 rpm at 166

Simon.