http://www.patmontmotorwerks.com/
http://www.youtube.com/watch?v=p8T53KPBvSY&feature=player_embedded
The video shows single sided front and rear swing arms, but without spring suspension. It appears to have good acceleration on flat ground. The design is clearly meant for using on other terrain than the street, such as off-road racing.
Their web site doesn't have any info however Autoblog Green says: "Weighing in at a rather trim 198 lbs, the bike holds 2.3 kWh of lithium polymer batteries and runs at 78 volts nominal at 250 amps continuous." and that it uses a Brushless DC motor.