Deep Dive: Vertical Range, Range and Efficiency: Which Motor System Gets the Most Out of Every Watt-Hour?

The article challenges the common assumption that a larger battery capacity automatically translates to a longer e-bike range, emphasising that efficiency is the crucial factor in determining how far an electric mountain bike (eMTB) can travel on a single charge. It highlights that simply comparing watt-hours (Wh) is insufficient because range depends on multiple variables including riding style, terrain, and the motor system’s ability to convert stored energy into forward motion. To provide a more accurate and comparable metric, the article advocates focusing on vertical climbing range—measuring how many vertical metres an eMTB can ascend per charge—since this accounts for gravitational work and is less influenced by external conditions. A significant portion of the discussion is dedicated to clarifying key technical terms related to e-bike performance, such as power, energy, torque, efficiency, and force. These definitions serve to demystify the physics behind eMTB operation and explain how energy from the battery and rider input is transformed into mechanical power. The article stresses that efficiency ratings, expressed as a percentage, indicate how effectively a motor converts electrical energy into mechanical output, with losses occurring mainly as heat and friction. Understanding these concepts is essential for interpreting test results and making informed comparisons between different motor systems. The article also explores the power balance on an e-bike, detailing how energy consumption varies with factors like acceleration, climbing speed, and resistance. It reveals that no-load power—energy consumed when the motor is on but not assisting—can impact overall efficiency and range. Through lab tests and real-world trials, the article presents insights into how different motor systems perform under climbing conditions, highlighting the interplay between system efficiency, rider effort, and hardware choices. This comprehensive approach underscores that climbing range is not solely dependent on battery size but is influenced by the entire drivetrain and riding dynamics. In conclusion, the piece emphasises that achieving the greatest vertical range requires optimising multiple elements, including motor efficiency, rider technique, and component selection. It suggests that riders seeking maximum climbing performance should consider these factors alongside battery capacity when choosing an eMTB. The article’s findings encourage a more nuanced understanding of e-bike range and efficiency, moving beyond simplistic metrics to embrace a holistic view of energy use and mechanical output in electric mountain biking.