We recently featured the high-performance electric Optibike, which was mentioned in a New York Times article. Well, apparently you can build a equivalent electric bike for much less (for around $1,600). See the video for more details, and see notes on the bike’s design after the fold.
The designer, Russ Finley, explains how he put the bike together:
- I chose a full-suspension mountain bike frame because the roads and even the bike trails here are so bad. I wanted to isolate the batteries, controller and my butt from the shocks. I also jump off curbs a lot.
- I wired pairs of 36-volt Dewalt power tool batteries in series to get 72 volts and then wired each of these pairs in parallel. I can carry two, four, or six battery packs, depending on how long the trip will be.
- I replaced my 36-volt, ten-amp controller with a 72-volt, 35-amp version. It also has immediate start, which means the controller does not wait until the wheel is rolling before it puts power to the motor. This lets me get through intersections faster and safer (although I have to be careful or my front wheel lifts off the ground).
- I used a rear wheel motor because front wheels here tend to get bent by potholes and fixing one can be expensive if you have a motor mounted in it.
By doubling the voltage I gave this bike twice the power of my first one. That is a 100 percent increase in torque and speed. It is an incredible machine — efficient, fast, carbon neutral, and flexible.