This electric bike is finished! I know I haven’t mentioned it before, but it is a key learning step toward building the electric plane.
There a lot to talk about with this bike, and I haven’t blogged any of it. In future blogs I’ll break it down and focus on lessons learned and interesting details.
- Sikk Fat Tire Cruise Bike
- 140 cell custom battery pack. Two 14s5p groups working in parallel to produce 50.4V (nominal) at upto 100A
- 2x “FlexBMS” Battery Management Systems.
- 3kW BLDC Hub Motor
- 3-4kW DC Controller/Inverter
- Raspberry PI 4 as central control of the system
- 5” touch screen for user interface
- Tail lights with brake lights
Officially, 20 MPH, because that’s the law for electric bikes. Unofficially, I may have exceeded 40 MPH.
I estimate it’s more than 50 miles. The bike was completed this morning and fully charge. Today I rode about 27 miles and the batteries are at about 70% of the top of their voltage range. Exact watt hours are challenging to calculate.
Undesirable! There have been a few unfortunate test rides where I was miles from home and without electric propulsion. Basically the bike broke for some reason or another and I had to pedal home. The bike is heavy! Maybe 100lbs. By the time I’d get home, I’d be drenched in sweat.
The picture above is the most recent version of the eBike, but it is not the first, or second. Below is a picture of the first version. It was a primitive configuration with a sad BDLC motor bolted to the frame and driving the rear wheel via an awkward chain.
Although version 1 was a blast to ride as you can see in the video as my good friend Skim gives it a go, the bike has improved a great deal since then.