
This bike has actually been sitting in pieces in my workshop for a couple of years now, after I partially disassembled it one day after getting sick of the unreliable old 2-stroke dinosaur burner. Here's a pic of where it's at now:

This will partly just be a toy, but also backup transport if I happen to be tinkering with the RX7 and need to get somewhere. I have fairly modest goals: Highway capable, 40km range (at 60km/h), and acceleration no worse than original - not hard as it was only a 150cc. Here's the plans so far:
Motor: Motenergy ME1003. 72V, 12kW continuous; a bit like an Etek only bigger. The no-load speed of these at 72V is 3700rpm, but I believe these motors are OK up to 5Krpm so I plan to run a higher voltage pack, and limit the motor voltage to about 100V.
Controller: One of my MC600SPs (150V 600A DC). The motor is rated to 200A continuous or 400A for 1 minute. So I expect it'll have no trouble with 600A for a few seconds.
Battery pack: 36S12P pack of K2 26650EV cells, for no better reason than I have a few boxes of them sitting in my workshop from way back in the days when I retailed them through ZEVA. So it'll be 432 cells, 115V 38Ah (4.4kWh), about 35kg, 20L volume.
In truth I would rather not build a pack from 432 little cells but they are basically free, and they do have relatively good energy density which is useful in motorbikes with limited space.
Performance estimates: At 100km/h the rear wheel (Ø62cm) would be doing 855rpm. A drive ratio (simple chain drive) of 4:1 would have the motor doing 3420rpm, seems about right. The datasheet indicates the Motenergy ME1003 has a KV of about 51rpm/V (this is linear with PM motors), which converts to a torque constant KT = 0.19 Nm/A. So at 600A, the motor should have 114Nm torque, making 456Nm at the rear wheel, or 1471Nm acceleration force. Assuming 200kg weight including rider, that's about 0.75G.. should be plenty!
As this will be my first bike conversion, I welcome technical suggestions from anyone who has experience converting bikes. Is 40km range from a 4.4kWh pack realistic?