At a quick glance the controller uses 12 MOSFET’s with 4 per motor phase. This and the various signals from the throttle etc are controlled using a Sinowealth SH79F1611U microcontroller.

https://datasheet.lcsc.com/szlcsc/1809140319_Sinowealth-SH79F1611U_C182003.pdf

Later on I shall give a more detailed analysis of the controller.

I purchased a 36V kit from eBay which includes a 26″ rear wheel with hub motor, motor controller, switched brake levers, throttle and pedal assist sensors.

The battery is a 36V 15Ah unit with a downtube/bottle cage mount.

I found a 1990’s ‘Muddy Fox’ mountain bike to use for the basis of this electric bike conversion. Old steel frames have some advantages over modern aluminium frames when it comes to wedging large motors in them.