Upcoming Power-Assistance System
In October 2007 we tested the 2nd Sunstar system I'd mentioned in the last newsletter (see N/L No.10, May 2007). We found it had a number of problems. For example, unlike with the previous prototype, we could not adjust the speed (which was mainly too slow); and, during testing, the gears in the motor stripped. After some consultation with the manufacturer, we gave up working on the Sunstar.
In January 2008 I fitted a Cyclone 500-watt gear motor to my personal gts trike. Like the Sunstar unit, this motor works through the trike's gearing system, making it more efficient than most hub motors, which have a fixed single speed only. The Cyclone unit came with a 16-tooth (t) fixed cog and a 16-t freewheel. So I ran a chain from a single 53-t chainring on the cranks, to the freewheel on the motor, and another chain from the 16-t cog to another 16-t cog on a Rohloff rear hub. This gave me a gear range from 18 to 95 inches, and maximum speeds in the 14 gears from 10 kph in 1st gear to 40 kph at the top-- without pedalling! More importantly it enabled me to ride straight up a very steep hill, which I'd been unable to do before without stopping about three times to let my legs recover...
The big disappointment, however, was that I got only 4 amp- hours from the 10 amp-hour Cyclone lithium-iron-phosphate battery pack, and one pack failed after only a week of use. So I put two packs together to make a 20 amp-hour pack. This was a lot better, providing 14 amp-hours. On the other hand, it became rather large and heavy (6 kg) that way. I then decided to try a Battery Space 21 amp-hour lithium polymer battery pack, much smaller and lighter at 2.8 kg. As well, it gave out 16 amp-hours, which means I only need to charge it up once a week. The only downside of this this battery pack is, it was not supplied with a box or a bag to protect the battery. We will need to find one to fit it before we can market this as an option. The motors are available in 180, 250, 360, and 500 watts.
