Build Your Own DIY Electric Bike and Extend Your Range
Photo: Rainer Jensen/dpa/Corbis
Souping up your old steel frame to add a little extra speed and power in the form of an eBike isn’t as difficult as you might think. Search Google and you’ll quickly find at least 15 kits that come with the essentials: a motor, a motor controller, a throttle, and an e-brake, which start at roughly $400. It’s smart to buy the battery and charger separately so you can find exactly the voltage you need.
Before you start to build, keep this advice in mind from Stan Soliday, founder of the website evsroll.com, a site that offerrs e-solutions for all manner of transportation: “It’s important to realize you are not building a motor bike. You are building a power-assist vehicle. The energy in an average eBike battery pack is not much: a 10 amp hour, 36-volt battery back has the energy in just one or two ounces of gasoline.”
And don’t bother to build muscle: Street-legal speeds in the U.S are only 20 mph. Ride in excess of that and you risk getting busted by the cops or, worse, killing yourself.
Step one: Define your needs
To find the balance between having enough power, yet conserving your battery’s limited energy, figure out what kind of riding you’ll do: Is your area flat or hilly? Will you be riding into the wind? What is the combined weight you expect to haul around? How far do you need to ride your eBike?
Step two: Pick your bike
Pick the appropriate bike to overhaul. Ilia Brouk, owner of ebikessf.com recommends a steel frame. “The heavier steel bike you have, the better,” he says. “Steel bends, aluminum cracks. Steel is definitely safer.”
The only downside, he adds, is that new steel bikes with components like disc brakes are hard to come by. If you need to resort to aluminum, you might need to buy an extra component called a torque arm, a metal part that slips onto the motor axle that prevents spinout when you put a lot of power on the motor. Brouk also recommends overhauling a hard tail instead of a full-suspension bike because it’s much harder to install a rack—where you’ll put the battery—on a rear-suspension bike.
Step three: Install the motor
Choose a motor. The three major types are:
Hub Motors: A motor built into the wheel itself, which can be put on the front or back wheel. The advantage to a hub motor is that it’s more streamlined, a lot lighter, and provides a better power-to-weight ratio.
Direct Drive Motor: This motor spins the wheel. It’s less efficient, and heavier, but it provides a lot more power, up to 2880 watts and can go as fast as 40 mph, way faster than street-legal speeds.
Mid-Drive Motor: It drives the chain. The upside is that you have a really wide gear ratio and it’s very efficient. The downside is that it’s more expensive (a kit starts at roughly $3,000) and makes a lot more noise because of all the force moving through the chain.
Step four: Select a battery
Choose a battery: The battery is the most important and most expensive part of an eBike. It’s smart to buy a lithium battery from a reputable U.S. manufacturer that has a decent warranty, the best batteries use Sony, Samsung, or Sanyo cells inside the battery pack. Buy one from China and you risk having to ship it overseas for repair. AllCell Technologies based out of Chicago manufactures high-quality, long-lasting 24- to 48-volt lithium batteries. Topeak Cycling Accessories has a variety of foam-cell bags for safe storage.
Step five: Assemble the pieces
After everything is ordered and in-house, it’s just a matter of assembly: It might be easy or it might be hard. It all depends on your bike frame and how handy you are as a bike-mechanic. If that sounds daunting, keep it simple and order the BionX system through NYCEWheels. This system, which comes with a 250 to 350-wattt motor, lithium battery, charger, bracket, console, and a hardware kit, ranges in price from $999 to $1,899. In four hours you’ll be powered up and puttering down the road.
Photo: Daniel Simon/Westend61/Corbis