I have added an electric power assist onto a GT mountain bike. With a 3 HP peak motor, it is much more powerful than typical electric bicycles. The basic motivation to build an electric bike was to have a fun and efficient and environmentally friendly way to stay out my car for short trips around town, and also as a silent trail bike for exploring the hills. I wanted to get some exercise - this bike can still be pedaled. When I first put this together it was even more of a blast to ride than I had envisioned. I have seen 70 year old people get on this bike and laugh like little kids - it's like a magic hand is silently boosting you along. This website will describe the background of this little electric vehicle, offer some reflections on the electric and hybrid vehicle scene, and detail most of the design and motor and batteries should you be interested in making one yourself. Though it's a bit of a project, a number of people have actually made very similar bikes based on my basic design.
The Beauty of the Electric Bike
No noise - no vibration - no smog - no smog checks - no registration - no insurance - no driver's license
No gasoline - no oil - no tune-ups - no parking hassles - no car payments - no more exercise (use the pedals) - no brainer Background: Why build an electric bike? Why use such a big motor? I love the idea of electric vehicles in general and would love to have a pure electric car. I have a Prius, currently just about the closest thing available. However, battery technology hasn't advanced enough to make a pure electric car affordable yet. I do think, however, that light-weight, low-speed, short-range vehicles are wellt within the limits of current battery-electric technology, so I set out to see what could be done to make a more powerful and longer-range motorized bike. Since I live about 3 miles from my favourite grocery store and my house is at the top of a fairly long and steep hill, biking and walking is just strenuous enough to be discouraging to me on a spur-of-the-moment basis. However I love biking. I have mountain bikes and folding bikes. In looking for a motor to add to one of my bikes, I rode some ready-made bikes and noticed that they are really fun to ride. The silence and effortless cruising along is just magical. But the electric bikes and motor kits for sale at the time, such as the Curry USProDrive, the eBike, etc. were fairly low power and really aren't that much faster up a steep hill than an unassisted bicycle. The Wave crest was the first decently powerful ready-made bike, though the company didn't last long. (Electric vehicle companies seem to have a curious habit of making a big splash - and then vanishing beneath the waves.) Now you can buy decent electric motor kits from Wilderness Energy and Crystallite, among others, but I was curious about the nuts and bolts of things, and wanted to learn more about exactly what it takes to drive a vehicle with pure electric power. I am a great fan of all electric vehicles and watch the new technologies closely. Hybrid cars are a tremendous technology that in my opinion is the first step on the road to all-electric vehicles. Hybrids will necessarily drive the development of better and cheaper batteries, which is the only missing link to the puzzle. Hybrids of today that are only charged by their gasoline engines will lead to 'plug-in' hybrids that can be partially recharged at home or at charging stations. This will lead to astonishingly frugal use of fuel, but these cars will need much larger battery packs, which means better and cheaper batteries will have to be produced. This will happen and is probably happening right now. Eventually batteries will become so much better that the auto companies will start to produce cars that simply leave out the combustion engine altogether - the pure battery electric vehicle. Don't get me started on fuel cells and the much hyped future 'hydrogen economy.' This...