I came across these scooters and a few quick searches didn't come up with anything on here...i'm sure a few of you might have heard of them but for the rest of you hopefully you find this as interesting as i do!
http://zelectricvehicle.com/15.html
their top of the line 10kw continuous motor claims a top speed of a blistering 78mph and (at 65% power) a 140 mile range (with a whopping 10kwh battery!)
some of you might recognize the second motor here:
ZEV states "The problem for our competitors is that because of their small motor diameter, they must run high amps to the motor to get the torque we get at lower amps.. But losses due to resistance are equal to the motor current (amps) squared x resistance. The inherent problem with increasing current is that an electric motor is basically a resistor, and the heat generated by a resistor increases with the square of current. Double the current, and you've got four times the heat to dissipate; triple the current, and you've got nine times the heat."
it is clear that their motor is much larger/should be better at distributing heat/running for long periods of time - especially considering that their motors contain an oil bath.
this is the only picture of the inside of one of their motors that i could find (a few years old by the looks of it) - it looks very similar to something like a 5xxx crystalyte or cro motor but quite a bit larger and wider!
*cro motor for reference*
imagine one of their top of the line motors running in a moped (or possibly highly modified downhill bike
) with a 200-250 lb weight! not only would the motor be able to run almost all day without overheating, i think you could easily push closer to 15-20kw relatively continuously (with less than 1/2 the weight) and probably even 30kw+ peaks no problem!
the only downside i see to a setup like this (besides not having many useful graphs/pricing information available atm) is that the motor is a 3 phase. a 6 phase seems like an advantage in that you can use 2 relatively cheap controllers together to run a high powered setup.