Good news, a package from Hong Kong arrived today (less then three working days from China to my door - pretty good).
The motors look very well made and finished, particularly given the low price (about £25 each). The machining looks very good and the stator windings are even and nicely encapsulated in what looks like epoxy varnish. Overall, the size is a bit of a shock; although I knew that these motors were small, when you have one sitting in the palm of your hand it really brings it home just how incredible it seems to be able get so much power from such a small package. Two of these tiny motors can pretty much equal the power output of my much bigger and heavier Mars PM motor in the bike.
I can't start testing until I get the controllers and rig up a suitable power supply. I also want to rebuild the motor dyno and try to fit some temperature sensors inside the motors. With luck I should be set to hook up a data logger and do some definitive measurements on real world loaded performance in a couple of weeks or so.
Jeremy
[edited to add:
There is no such thing as a new idea, it seems. The following link shows that another EV company is already following the same path as I outlined with this post, by using multiple BLDC/controller modules on a common shaft to realise high efficiency and light weight from a low voltage supply.
http://evaira.com/Propulsion.html. The same company claims to have some interesting battery technology too.]