Building an Electric Bicycle
Electric Bicycle
II - Getting the Parts
III - Assembling it All
IV - Controller Programming
V - Test Rides
Cost Spreadsheet
II - Collecting the Parts

Whenever I start a project, I have a tendency to underestimate the time, effort, and expense. This project was no different. I already had a controller. I had experience working with brushless motors. I thought, "All I need is a hub motor, a few connectors, some batteries, and time to mount everything on my current bike." As I began getting things together and documenting each of my purchases in a spreadsheet, I realized that this project was going to be more expensive and time consuming than expected.

Well, at least I had the foresight to order a throttle, a torque arm, and a freewheel from Cycle 9. That was a start. But while waiting for that shipment to arrive, I started reading the instruction manual for my Kelly Controller, and realized that I needed a brake switch, which meant buying a new brake lever. That also meant buying mating connectors to hook the brake switch to the controller, and I had also forgotten that the hall throttle would need a 3-pin connector to mate with the one on the controller. Luckily, the supplier I found for the brake lever also sold these connectors.

To program the Kelly Controller, I would need a computer with an RS-232C interface. I have an old desktop computer out in my garage that has that interface, and in fact, had used that computer before when I was programming the controller for use on my electric scooter. But I now had a small netbook computer, which I wanted to carry with me during my experimental rides so I could change settings and see how they affected performance. The netbook had only USB inputs, so I searched the internet for a cheap USB-to-RS232 interface. I ordered that. I also ordered four Amstrom 12V 8 AmpHour SLA batteries from I chose them because they were a US supplier, and they offered free shipping, so even though their price was $5.00 more per battery than the cheapest supplier, they still cost me less.

The next day, I rode my electric scooter to work and back. Arriving at home, I plugged in the charger, and in doing so, realized that I would need a charger for the electric bike as well. I could, of course, use the scooter charger, but I like to take my charger along with me so I can recharge at work, and that would be a hassle, especially if my wife wanted to use the scooter while I had the bike. I ordered a 48 volt charger on E-Bay, from a seller named mybestbuy2007... $21.00

Cycle 9 finished lacing the rim onto my motor and shipped it. It arrived about 10 days after I ordered it. I unpacked it, took out the instruction manual, and read it front to back. Of all the electric bike and scooter information I have received with products from China, this was the first instruction manual that was written in understandable English, and was concise and complete It was obviously written by the staff of Cycle 9. My compliments to them for making sure the buyer has an understandable set of instructions with their product

Cycle 9 had assembled the freewheel to the hub before shipping it to me. I checked my bike to see how the motor would fit. As soon as I removed the rear wheel from my Schwinn Sierra, I knew I would not be able to mount the wheel in that bike. The tire would be too far off center to clear the frame. It was also obvious that the Cycle 9 tech had compensated as much as possible by dishing the wheel as far as he could to the right, but it was still not enough. I checked my wife's Trek 300, and though the tire would clear the frame with her bike, I would still have had to make significant modifications to her frame to line up the rim close enough so that the brakes would work.

I decided to go with my alternative plan.... buy a cheap steel frame bike to mount the wheel into. I went with a Ladies Schwinn Link from Wall Mart at $159.00. While there, I also purchased a bike speedometer, and a handlebar mounted basket. I got that bike home, adjusted the shifters to my liking and rode it around the block a couple of times to get a feel for how it rode. For a cheap bike, I was pleased with the performance.

I took a look at the total on my expense spreadsheet, and began to wonder whether I should have just bought a pre-built electric bike. But then I remembered the quote from Cycle 9... "More efficient than Crystaltye, these motors easily compete in performance to some of the best out there, reaching speeds of 30mph without sucking down your battery." I was certainly hoping that was true. I pressed on to assembly.