For the UltraCommuter there are a number of parameters that need to be met by the drive system. These parameters are made up of performance requirements and various system constraints. The first constraint is that the motor must fit within the rear 17” wheel rims, corresponding to an outer case diameter of approximately 390mm. The second constraint is that the motor should not add excessive unsprung mass to each of the rear wheels - it was decided that a final cased motor should not weigh more than 25kg. Performance requirements dictate that the motor develop 500Nm peak torque for 5 second intervals and 250Nm for upwards of 3 minutes. A vehicle top speed of 170km/hr equates to motor speed of 1500RPM (where phase connections and bus voltage permit).

Since 2003 various prototypes of  UltraCommuter’s direct drive wheel motors (or variations of them) have been fabricated and subjected to dynamometer testing and evaluation.  Single stator versions of our motors powered an an electric-only version of the UltraCommuter as a joint entry of HybridAuto and Waikato University in the Prototype Experimental Vehicle Class of the 2007 World Solar Challenge.  In 2006-07, and with a view to commercialisation of our direct drive wheel motors HybridAuto received assistance from an Australian automotive technology and component group (commercial-in-confidence) in the drafting of an Australian patent application that was filed in April 2007, entitled "Winding Arrangement for an Electrical Machine".