Appreciate the vote of confidence but this is a budget conversion both in terms of money in time so i'll live with a chain. I do have an option on a bmw k75 for version 2 which is shaft drive

So I need a little advice on the sprockets. The bike's stock ratio is 2.87:1 with a 15 tooth on the engine and 43 tooth on the rear. So i've done some maths and came up with the following.

Wheel diameter : 600mm (approx)

so one turn = 1.885m

so for 1kph the wheel would turn at 8.83rpm

speed_________wheel rpm_______Motor rpm (2.87)_______Motor rpm (3.58)

50kph (30mph) = 441---------------1265-----------------------1578

100kph(60mph) = 883---------------2534-----------------------3161

145kph(90mph) = 1280--------------3673-----------------------4582

I can achieve a 3.58 ratio by keeping the stock rear sprocket and going to a 12 tooth on the motor. Bearing in mind its a twin motor setup I'm guessing i will have plenty of torque even with such a low ratio , still let the motor spin fast enough while holding them in the power band. Most bike conversion i've seen on the web have anything from 1:4 to 1:7 ratios but most are using agni or perm motors. Any advice much appreciated.