Abstract: Multi-speed fixed gear hub transmissions are provided for push rim wheelchairs. Push rim wheelchairs having such transmissions are also provided. The hub transmission generally includes a hub driver, a hub and a drive train, configured to transmit rotational force from the hub driver to the hub. In some implementations, the drive train transmits torque at each of at least three gear ratios, and defines at least three different torque transmission paths between the hub driver and the hub, each path defining a respective one of the gear ratios, and each of the transmission paths including only rigid bodies, each of the rigid bodies being configured to transmit torque in both forward and reverse rotational directions. In other implementations, the drive train transmits rotational force at each of at least two gear ratios.

Abstract: A human-powered vehicle comprising a structural frame, two front wheels mounted to a forward portion of the frame for rotation, a seat secured to the frame, the seat positioned between the front wheels and adapted to pivot about a seat pivot axis, and a steerable rear wheel mounted to the frame behind the seat and defining a rear wheel kingpin axis, the rear wheel operably linked to the seat such that pivoting of the seat about the seat pivot axis causes pivoting of the rear wheel about the kingpin axis to steer the vehicle.

Abstract: A human-powered vehicle comprising a structural frame, two front wheels mounted to a forward portion of the frame for rotation, a seat secured to the frame, the seat positioned between the front wheels and adapted to pivot about a seat pivot axis, and a steerable rear wheel mounted to the frame behind the seat and defining a rear wheel kingpin axis, the rear wheel operably linked to the seat such that pivoting of the seat about the seat pivot axis causes pivoting of the rear wheel about the kingpin axis to steer the vehicle.