The output spline on the engine is 30mm. I haven't picked a bearing for the layshaft yet, but I have space for a big one (or 2). I guess I was just gonna use a 30mm and find a similarly splined shaft so I could use standard sprockets (or what ever the Honda uses). I had planned on a 12 tooth on the engine and an 18 on the layshaft. I am assuming I can find splined shafts somewhere.
My calcs show the output shaft on the engine spins at 2300 RPM at 11,000 RPM in top gear, so not too bad.
The book suggests simply using different length axles, I'm just not sure I can bring myself to do that
I know in RC cars that axle angle can effect the suspension action under load. I think the book addresses that too, and says the effect is minimal. My axles should be level at ride height and are pretty long so probably even less effect. But I'm kind of a symmetry freak...so...
The offset is 3.0225".
The input shaft of the layshaft is cantilever, the output sprocket is close to one side and the other end of the shaft is in a bearing. If I put 2 bearings on the input side I can reduce the cantilever a bit, maybe make the eccentric adjuster on that side super beefy (technical engineering jargon).
Oh, I cut the axle in half and turned it a bit to see if I can get a good fit to the extender tube (which I don't have yet). I must have gotten lucky with the tool and lathe setup cause I got an amazing finish on it. Maybe because it's chromoly or something. Hardness was a bit much for HSS but carbide cut it fine. I was amazed for a mini lathe. The most difficult part was getting a center hole in the cut end...a Dremel was involved.