Series parallel switching

Several people have asked how I wired the series parallel switch, so here's a rough sketch of the wiring diagram.

For the moment I am using a DPDT relay on the handle bars to manually switch. I am planning on adding an RPM check (to avoid switching accidentally at high speed from parallel to series) or even automating the process entirely.

Not only is torque greatly increased in series mode, but the regen function works more smoothly, and too a lower terminal speed than when the motors are in parallel.