A Nimbin ebike – competitive with a car on hills

PWF has just been contacted by Peter from the Rainbow Power Company in Nimbin, about how, with the right equipment and the gearing, the 200W power limit on electric bikes be ‘more acceptable’ in terms of hill climbing.

Rainbow provides electric power systems from sustainable energy sources and they also run courses in ‘Living with Solar’. Check out this really friendly website, photos of the whole crew…Peter is at the bottom left ‘designing a system’ in the Rainbow building, one of the largest passive-solar buildings in the Southern Hemisphere.

Peter talks about the power limit on ebikes:

“I have been experimenting with pedal power for 27 years, both for stationary (eg pedal juicers, blenders, spin dryers etc) and mobile application. Throughout this time I have often experimented with power assisted pedal transport and I was never satisfied with the 200W power limit.

Recently I discovered ebike kits where the motor power is transmitted through the standard bicycle gearing system.

I live at 350 metres altitude and work at 60 metres altitude, a distance of 12 kilometres and with a standard 200W ebike kit without motor gearing designed to give a reasonable speed on the flat does not have sufficient torque to give any assistance at all up the steep hills between work and home. This makes the electrification of the bike worse than useless as I now have the extra weight of the battery and motor to cart up the hill entirely with my pedal power. I gave up on that idea in frustration.

Over the last year I have built up 2 ebikes and 1 etrike using the motor through the 15 or 21 speed derailleur system and have been commuting between home and work every day for the past 8 months.

This bike has 28/40/48 tooth chainwheels and a 14 to 34 tooth rear cluster and I manage every hill until the final steep grade up to my house without dismounting. On the way to work (mostly downhill) I exceed 60kph and average 35kph on a windy road and cover the distance in almost the same time as I would by car. This ebike has a 36V NiMH battery bank which I charge up from solar power at work and at home.

The more recently assembled ebike is a step-through frame, has a 22/32/42 chainwheel set and a 14 to 40 tooth rear cluster using a Lithium Ion battery pack and, with this, I can pedal up inclines to the point where the front wheel lifts off the ground without excessively exerting myself. Thus, with the right equipment and the gearing, the 200W limit has become less of a limit in terms of hill climbing.

The etrike is used as a utility vehicle to carry large amounts of parcels from work to the Post Office.”

For more info

Email Peter Pedals pp@rpc.com.au at the RAINBOW POWER COMPANY LTD, P.O. Box 240 Nimbin NSW 2480 Australia.