Cargo e-bike review: Swoop ASM's auto-shift is smart but not smooth

The Swoop ASM is a steel-framed long-tail cargo e-bike with a Shimano automatic transmission that selects gears based on rider input. In testing, the system made sensible gear choices but executed shifts with noticeable roughness, though riders can disable it. Beyond the auto-shift feature, the bike offers a comfortable ride with front suspension and a low rear wheel for stable cargo handling.

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The Swoop ASM's automatic shifting draws on sensor data most modern e-bikes already collect—cadence, torque output, and the relationship between power and speed—to determine optimal gearing. Xtracycle, which began by producing cargo trailers for mountain bikes before pivoting to dedicated cargo models, positions the battery directly behind the mid-motor, a layout that also keeps loose clothing away from the chain. The steel frame, uncommon in an industry favoring aluminum and carbon fiber, delivers a notably comfortable ride and lively acceleration when the rider stands on the pedals.

The mullet wheel arrangement—a larger front tire paired with a smaller rear—