E-bike project - General E Lee

[Metallover]

Well, I got the inspiration to start another E-bike project. This time it's on a 20" DK General Lee frame. I am running a 250kv hobbycity outrunner and I want a 30mph top speed on 36v. I figured I need a 16:1 gearing reduction. Looking at what I have, I can make a reduction close to 16:1 with a 11/66 and a 15/40 reduction. If my math is right, that's a 6:1(2.6:1)=16:1. Do those numbers and ratios look right?

The hard part will be attaching a freewheel (15t) and my 66t spur (from scooter) to a 3/4" shaft running where the crank used to be. That will be the mian hub. The pinion on the motor will run to a spur on that hub then a spur on the other side of the hub will run to a pinion on the wheel.

The bike needs a 20" rear wheel to get it going. I'll get more pics when I buy wheel.

I expect the motor to be turning at 9000rpm, do you think a small electric scooter chain will be too loud? Should I use a belt instead?

Edit- forgot pics

Edit- pics blurry... thumbs for now.