E-Bike technology: Comparing motor types and transmission systems

The evolution of electric bike (e-Bike) technology is driving significant changes in motor placement and transmission systems. Regarding motor configuration, hub motors are often perceived as less reliable than mid-drive motors. However, this reputation frequently stems from the lower-quality peripheral components—such as controllers, sensors, and wiring—found in budget-friendly e-Bikes rather than the motor units themselves. Mechanically, hub motors offer the advantage of driving the wheel directly, which reduces wear on the chain, cassette, and derailleur, allowing the bike to remain mobile even if the transmission fails.

In terms of transmission, the high torque of modern mid-drive motors, often exceeding 85 Nm, is accelerating the wear of traditional metal chains. High-performance e-Bikes can see chain stretching and component degradation in under 2,000 kilometers. As an alternative, carbon fiber reinforced belts, such as the Gates Carbon Drive system, are emerging as a durable option for urban and trekking use. These belts can last over 20,000 kilometers, require no liquid lubrication, and are resistant to dirt and debris, though traditional chains remain preferred in disciplines where weight and precise gear stepping are critical.