This is my guide for building an electric bike. In this instructable, I will show what I did as well as how to build your own version. I realize that you will most likely not follow my steps exactly, so I tried to make this guide as adaptable as possible.
As I am still working on my project, I will update this periodically when I have something relevant to add. I will upload pictures of my work soon.
Step 1: Step 1:
Determine what the use of the bike will be. This involves quite a bit of research of what others have done, as well as what works best for you. Some good questions you should ask yourself before getting started:
What will this bike be used for?
How many miles will it need to travel before recharging?
How fast will it need to go?
What is your budget restraint for the bike?
These are important things to consider before you get started. If you do not define the parameters of your project before you get started, expect it to fall off track and short of your expectations.
Step 2: Step 2: Deciding How Much to Spend
While it is possible to finish this project without spending anything, it is likely that you will need to spend some at some point. It's best to decide how much you are are actually willing to spend on the project before you started. If you are willing to spend more, there will absolutely be better bikes that you could buy than you probably could ever make. With more funds, there will always better batteries, motors, frames, and controllers. That being said, often times there are many components that you can salvage or find.
Step 3: Step 3: Gather Your Materials:
A list of materials that you will need:
Bike frame. This can be an old one, or a recently purchased model. I used a bike that I had since I was a kid that I no longer used.
Motor. I chose an electric motor for my project. If you wish, a small gas powered motor would work. The specific motor that I used was one from a donated treadmill.
Batteries. You can choose to have a larger battery, but this will be harder to mount to the frame as well as weighing much more than necessary. Instead, I used cells from donated laptop batteries that I connected together.
Switch or controller. There are countless options ranging from just a light switch to an actual throttle on the handle bars. I chose to use a simple black light switch from Home Depot.
Step 4: Step 4: Deciding How to Build It
Before you start building the bike, you need to decide how to transfer the rotational energy from the motor to the wheel on the bike. Methods I have seen range from:
-Sprocket connecting the motor to the existing gear on the rear wheel
-Connecting the motor directly to the center of the rear wheel.
-Using a friction drive in which the motor turns the wheel by turning another wheel that rolls on the main wheel
I do not recommend putting the motor on the front wheel because the motor completely throws off the balance of the bike.
Step 5: Step 5: Building It
You will have to build an apparatus to hold both the battery as well as the motor. Most bikes have connection points to connect a cargo rack, and you should use this to your advantage. From here, you can buy an existing cargo rack and modify it to your needs, or you can build your own. I built my own cargo rack with salvaged aluminum bars.
Off of this cargo rack, connected thin steel plates that gave the cargo rack a platform to place batteries on.
For the batteries, I removed the cells from laptop batteries, and 3d printed two housing units to contain 10 of the 4 volt batteries.
I connected the motor by bolting it directly onto the frame.
Step 6: Step 6: Finished Product
Hopefully, you will finish your project and it will be if nothing else, at least a learning experience. Unfortunately my bike didn't quite reach a finished product, but that being said, I did have two successful live tests, carrying me around the school parking lot. The biggest problem I encountered was the connection between batteries. I could have definitely overcome this problem if I used my time throughout this semester more wisely. If nothing else, I still have the working bike I started with it. Additionally, I could simply purchase working batteries on amazon, but with that being said, it would be finished, however I would not have learned nearly as much in the process.