The paved hill has an 8% grade. The grass hill is even steeper.
The bike has a 9x7 9Continent 26" rear hubmotor with a temperature sensor/alarm and thicker phase wires, an eCrazyman 45a 72v controller with computer programming, and 10ah of 20c 66.6v turnigy lipos. It tops out at up to 42mph on the flats with the timing boost enabled. The bike makes 4000w of power.
Build thread with pictures - http://endless-sphere.com/forums/viewtopic.php?f=6&t=15192