I want to convert my bicycle to an eletric assisted bicycle. What is the easiest and cheapest option?

Question

Given the high price of fuel and the fact that I only work a few km's from work I dont want to use my car everyday. I already have a solar powered batterey pack that has both 12v and 24v outputs that I want to use to recharge the battery on the bike. Most of the trip to work is downhill so the motor will most likeley only be used to help me get home again. Thanks in advance.

Answer 1

First of all forget solar- the amount of power you'd get from a 1m square panel would take about three months to charge an ebike enough to ride for a day.  Most ebikes run on 24v or 36v systems; a 12AH battery pack will generally run them for a range of about 50km.

You can buy the components to build an ebike separately but it may be just as cheap to buy the whole thing.  If you want to DIY as a minimum you'll need:

1.  Wheel/motor unit- the motor is built into the hub.  250W is power-assist only, would not get you up a hill on its own.  500W will handle an incline of 10 degrees.

2.  Speed controller.

3.  Battery pack.  NiMH will last longer an get more range for the weight, lead-acid is cheaper.  NiMH are good for ~1000 charge cycles, lead acid is good for ~300 cycles.

In Canada you can get the components and complete bikes from Daymak (http://www.daymak.com).  They ship anywhere in North America.