Manual wheelchair propulsion system

A propulsion system for a manual wheelchair, the system comprising:

• a mounting clamp configured to attach to the manual wheelchair between two spaced-apart wheelchair drive wheels, the wheelchair drive wheels each defining a wheelchair drive wheel tire patch on a support surface, one of a cross-member, an axle tube or a camber tube defining a wheelchair mounting axis, the manual wheelchair drive wheel defining an envelope tangent to an outer diameter of the manual wheelchair drive wheel and the mounting clamp defining a propulsion unit mounting axis which are aligned when the mounting clamp is attached to the manual wheelchair;
• a propulsion drive unit selectively attachable to the mounting clamp, the propulsion unit comprising:
• a drive wheel assembly defining a drive wheel tire patch, the drive wheel tire patch generally in line with each wheelchair drive wheel tire patch when the drive wheel tire contacts the support surface, the propulsion drive unit drive wheel defining a drive wheel axis that is positioned within the envelope when the mounting clamp is attached to the manual wheelchair;
• and
• a support suspension configured to provide linear movement of the drive wheel and drive hub assembly relative to the manual wheelchair.