(These instructions were originally published on 7gen.com on September 14, 2005)
Early models of the EVT 4000e and EVT 168 electric scooters used brushed 1500 watt hub motors. They propel the scooter at up to 30 miles/hr and their scooters are quite fine and reliable machines. Hub motors are built into the rear wheel, making the motor also be the hub of the wheel, hence the name "hub motor". The implementation on the EVT 4000 is very smooth and quiet. The manufacturer is based in Taiwan, at http://www.evt.com.tw/
Submitted by HighTekBikes on Tue, 12/21/2010 - 19:36
There are two basic types of motors in wide use today for electric bikes, direct drive and geared. The direct drive has no internal gears or other moving parts except the actual case which rotates around the axle on sealed bearings. The coils are wound around an assembly that is fastened to the axle and remains stationary. The outer ring of the case has a ring of magnets that rotate in close proximity to the electromoagnets formed by the coils. As the coils are energized in a specific pattern by the motor controller, the magnets are attracted and repelled causing the wheel to rotate.
While nearly at work this morning the hub motor on the Gelato started to make an odd groaning/grunting noise at low speed. At higher speeds the sound stopped. The sound made it seem like it was working hard to get started. Luckily it was less than 100 yards from work.. I put the bike on its stand so the back wheel was not on the ground and turned the throttle. It still made the same noise. At one point the wheel did not even turn without some urging. Once it was going it turned without a problem. All of this was after about 4 miles of riding.