[TomEV]

Looks like an interesting project! I'd do a bit more research before committing to 2.85:1. Most of the motorcycles in the EV album seem to run at least 4:1 - many are around 5:1. Similar motorcycles (shaft drive) seem to universally use a pillow block/aux shaft reduction setup.

With the Citicar / Comutacar, you may have noticed a significant difference in speeds with the two normally available differential ratios. Comutacar/Dana at 5.17:1 are somewhat faster but don't accelerate as well as the Citicar/Terrell 7.125:1. At least for the C-car application, I'd pick something closer to 6:1 (happy medium between speed and acceleration).

Let us know how it goes...