Have you ever thought about building your own motorcycle? The TV shows make it look so easy, don’t they? But, I’m not talking about a chopper, I’m talking about an electric motorcycle. And not just any electric motorcycle.
Not long ago, contractor, carpenter, and renewable energy enthusiast James Biggar designed and built his very own electric motorcycle from scratch. By attaching a 72-volt motor to a welded steel tube frame wrapped in custom molded fiberglass body, the end result is an electric bike as street-worthy as any motor vehicle, and cooler than most electric motorcycles on the market today.
Building an Electric Motorcycle
As mentioned, the frame is constructed with welded steel tubing, 1” square, 11-gauge steel tubing. To help decrease its weight and fit in the different parts, James drills a bunch of holes into the frame.
Even some essential motorcycle parts are made completely from scratch. For example, the footrests are made by screwing ¼” bolts into modified pieces of 1” x 2” tubing. And the kickstand is made by combining 2” x 2” square tubing, a 1” pipe, and a ¾” steel bar.
The frame, in all of its angular glory with a minimal aesthetic is powder coated, what else, but matte black.
There are some parts which just can’t be forged from steel tubing, such as the rear suspension, the downhill forks, and of course, the motorcycle’s wheels. James adds these in after the frame has been painted and assembled.
With most of the hardware in place, he starts adding the wires and electrical components. To control the 72-volt motor, James installs a 72V/150A motor controller underneath the frame. The electronics do much without a battery and boy, does this motorcycle have a big one. Located just below the motor controller is the area to hold the lil’ mini-fridge-sized 72V/60Ah battery.
Up top, he adds the control components, the throttle, handlebars, brake levers, display and switches, all purchased but perfectly matched for the project.
To aid the brake levers, he adds a motorcycle braking system on the wheels and a 72VDC/150A breaker switch between the motor controller and the battery. He installs a anti-spark connector between the breaker switch and the battery before finally connecting the motor controller to the battery.
The rest of the build focuses on the build of the fiberglass body components: the fairings, cowling, and other body panels. James uses laminated plywood for the forms before making molds out of silicone.
Once the molds are finished, he goes through the layup process, starting with a layer of fiberglass mat and adding 3-4 layers of fiberglass cloth before casting the parts with polyester resin.
This is the exciting part – where the form side of the design, though alreasdy intertwined, meets the function side. Each parts is trimmed to fit the bike frame before the final finish and the complete profile of the motorcycle is revealed.
The only things left to add is a seat pan and a comfy foam seat covered in vinyl. The seat build, foam layup, and upholstery work is a small process in itself but James keeps it minimal to match the top profile of the bike perfectly.
Taking the electric motorcycle on a test run reveals it can run around 65 mph (105 kph) with a top speed of 75 mph (120 kph). According to James, the bike has a continuous output of 8,000 watts and a max output of 12,000 watts.
For power and speed gain, it has a maximum torque of 190Nm and an acceleration of 3-6m/s2. The reported max speed is 90mph with the battery providing around 60 miles (100 km) on average terrain before it needs to be charged.
If you have prior experience with cutting steel tubing, resin casting, and installing electronics, James Biggar has made the CAD plans available to download for $10 from his Renewable Systems Technology webpage.
Included in the plans is a complete list of tools and materials as well as the Sketchup files. This is a project designed for more experienced builders, as James doesn’t really include a step-by-step process on how to do certain things like cut tubing or resin cast.
Whether you plan on making this electric motorcycle for yourself or not, you can’t deny that making your own electric, road-worthy vehicle from scratch is a project that could have some long term payoff, both in learning and transportation cost.
If you’ve undertaken a project like this, let us know in the comments or share it with us to feature on SolidSmack.