Power comes from a 700W rear hub motor that Specialized custom-tuned for cargo duty, paired with a 772Wh battery offering up to 60 miles of range under typical conditions. The motor delivers Class 3 pedal-assist speeds up to 28 mph, though loading the bike with passengers and gear realistically means cruising closer to 20 mph on flat terrain. An optional throttle converts the bike to Class 2 operation when pedaling assistance alone won't get a heavy load moving from a standstill—useful when stopped on an incline with kids aboard. The hub motor arrangement places the heaviest drivetrain component at the rear wheel, which complements the weight distribution when the cargo deck carries its intended load rather than fighting against it.

The torque sensor feeding the motor responds to pedaling pressure rather than simple cadence detection, which means power delivery scales with effort. Light pedaling produces modest assistance; pushing hard into a hill with cargo generates the full output the motor can provide. Five assist levels allow riders to balance range against effort depending on the day's demands. The battery mounts externally for easy removal, charging off the bike if preferred or remaining in place for overnight charging in a garage.

Specialized designed the Haul LT around a single frame size that accommodates riders from 4'5" to 6'4" through a telescoping seatpost with 13 inches of adjustability and a quill stem that extends nearly 6 inches. This range means the bike can serve multiple family members without requiring separate machines for different sized riders—a practical consideration given the investment a fully equipped cargo bike represents. The 20-inch wheels throughout drop the cargo deck low enough for easy loading while improving stability under load compared to standard 700c configurations. Smaller wheels also mean a lower center of gravity, which pays dividends when navigating parking lots or making tight turns with a full passenger complement.

The front rack adds another 44 lbs of carrying capacity to the equation, mounting directly to the head tube where the weight affects handling less than fork-mounted alternatives. The Thule basket provides a ready-made solution for smaller cargo that might otherwise shift around on an open platform—keys, phones, wallets, and the miscellaneous items that tend to get forgotten in pockets find a secure home up front where the rider can monitor them. Between the front rack, rear deck, and the space that remains even with two passengers aboard, the practical carrying capacity approaches what a small hatchback offers without the parking problems or fuel costs.

Stopping 441 lbs of combined bike, rider, and cargo requires serious braking hardware. The Tektro HD-T535 hydraulic disc brakes use 4-piston calipers and 203mm rotors at both ends, providing the power and modulation necessary for confident stops even on descents with a full load. The 4-piston design spreads braking force across a larger pad surface than the 2-piston calipers found on lighter-duty bikes, which translates to better heat management during sustained braking and more consistent lever feel throughout a ride.

The microSHIFT Advent 9-speed drivetrain pairs with an 11-36t cassette, providing the gear range necessary for climbing loaded while maintaining a usable high gear for assisted cruising. The 160mm crank arms account for the lower bottom bracket height that comes with 20-inch wheels, preventing pedal strikes during cornering. Integrated lighting runs off the main battery, with a 1500-lumen headlight bright enough for unlit paths and a 50-lumen rear light ensuring visibility from behind. Full-coverage fenders and rear wheel covers keep road spray contained, and the extra-wide center kickstand provides the stability needed for loading and unloading without the bike tipping under asymmetric weight.