Super73 S2

Super73's best known bike, and the reason to pick it over the ZX at the same $2,395 is the brakes and the sensor: hydraulic rather than mechanical, and torque sensing rather than cadence, so assist tracks how hard you push instead of arriving in full the moment the cranks turn. Otherwise the same 480Wh pack, the same single speed, the same rigid frame and the same 4.5 front / 5 inch rear tyres, at 67 lb against 62. Sensor type comes from Super73's own guide at eu.super73.com/blogs/guides/cadence-and-torque-sensor, because no product page states it. The battery is "UL2271 Compliant", which is weaker than certified, and there is no system claim.