Gold Rush Drivetrain with Lashout Gearbox and 120t #25 chainring
A 19t sprocket is on the output of the planetary gearbox. At 26 volts, full throttle gives 105 RPM at the crank. This installation uses the planetary gearbox fabricated by Scott MacGregor of EVDeals and uses an 18mm pinion shaft and outboard bearing (rather than brass bushing) for greater efficiency and reliability. Note also the extra tube welded over the gusset at the headtube/downtube crotch, added after a recent frame crack. This is the weakest part of the Gold Rush frame, and the extra weight and speed from this bike puts extra stress on the frame at this point.