Abstract: A drive wheel 10 is shown to include a support member 12 and, a wheel member 11 having a surface contacting portion 18 extending about a periphery of the wheel member 11. A drive shaft 24 includes a drive device 25 arranged to engage a drive surface 26 on the wheel member 11 such that the wheel member 11 can be rotatably driven relative to the support member 12. When the drive device 25 is engaged with the drive surface 26, a line of engagement 27 is defined along portions of the drive device 25 and the drive surface 26 that engage with one another.