Electrify Your Ride

Converting Your Bike to Electric

Inside this Article

Electric Bike Ride
The newly electrified bike goes for its first test drive—with success!
Rear-Wheel Hub Motor
A rear-wheel hub motor.
Outboard-Mount Currie Motor
An outboard-mount Currie motor and drive.
Dual 1,000 Watt Golden Hub Motors
Dual 1,000 Watt Golden hub motors give near-motor-scooter performance.
Lithium-Ion Battery Pack
A rack-mounted lithium-ion battery pack.
Thumb Speed Control
A thumb speed control.
Motor Speed Controller
A motor speed controller.
The E-BikeKit comes with the motor (the wheel shown in the box) and controller. The battery (the silver tube), charger, and rack came separately.
Electric Bike Ride
Rear-Wheel Hub Motor
Outboard-Mount Currie Motor
Dual 1,000 Watt Golden Hub Motors
Lithium-Ion Battery Pack
Thumb Speed Control
Motor Speed Controller

I have to confess—bolting a motor onto my bike has been a fascination of mine since I was a kid and first saw the DIY gas bike kit ads in the back pages of Popular Mechanics. It was probably second only to the idea of strapping a bunch of hot-air balloons to a lawn chair and coasting over the trees in my neighborhood. 

Although I’ve come close to building something like my motorized bicycle boyhood fantasy, it always got eclipsed by something more practical—until I saw the electric conversion kits. 

Converting a standard bicycle to electric power is remarkably simple. You can approach it from a complete DIY perspective and build it all from scratch; you can adapt motors and parts from salvaged electric scooters; or you can buy complete turnkey kits with everything you need—instructions and all. Finally, the fantasy became practical. 

Why Go Electric?

There are plenty of reasons that people like electric-powered, or electric-assist bikes. They’re so much simpler, smaller, and lighter than electric motor-scooters or motorcycles; they can be pedaled efficiently and easily; and, in most states, you don’t need special licensing or permits to ride them. Electric scooters’ pedals are just for regulatory show—to qualify them for “motorized bicycle” status in the eyes of the government. They are too heavy to pedal, realistically. Electric bikes allow an avid bicyclist to enjoy the open road, and help out on the hills or on that long road home. They can help you keep up with the group, if you like to ride with more extreme bicyclists. 

They also let you pull more weight—for a trailer, groceries, or gear to the beach—and you can jump on the bike, run your errands, and come home without a huge workout. You can use the bike for a commute, and arrive ready for work without the need for a shower and a change of clothes. 

Police departments find an advantage in electric bikes: They can pedal around all day, and enjoy all the benefits, tactical and otherwise, of “bike detail.” However, if they get a call some distance away, the 30 mph top speed of many of these bikes can quickly get them where they need to be without being winded when they arrive. 

For city dwellers, electric bikes are light enough to bring into a building and up elevators for storage and recharging in your apartment—something you just can’t do with an electric motor-scooter. If you’re keeping yours on the street, the removable batteries of an electric bike allow for easy in-apartment charging. 

“Range anxiety” is avoided with an electric bike. If you run out of battery energy, you simply switch to leg-power and pedal your bike home or to the nearest electrical outlet.

Conversion Parts

Factory-built electric bikes can cost in the $1,200 to $1,800 range, not prohibitive to bicycle enthusiasts, but the kits can be cheaper, from $400 on up. The components include the bike, motor, motor controller, batteries, and rider controls. There are a few extras available, but those are the basics.

Bikes. The choice of bike for the conversion process really is up to you. Kits are made to accommodate standard, modern designs. With the exception of only a few obscure models, nearly any bike will convert easily. 


Comments (3)

Mark Smith W4CHL's picture

Quick comment: in the interest of simplification, the author should not have linked "speed" of an ebike motor to battery pack voltage. Peak speed under power is regulated in many countries, and even some areas within a country. Across the US the federal law is the motor assist must kick out at 20mph and the motor may be no larger than 750w (~1hp) to maintain the unlicensed ebike status. Most older systems are 24v, newer are 36v or 48v. Some may be modified to run faster, but the limits are not battery voltage, but the controller electronics and the motor peak wattage/hp.

Michael Welch's picture

Thanks for the good info, Mark. Yes, the federal limit is held to 20 mph and 1 hp for commercially-made bikes. But if you make your own ebike, state laws kick in. Here in CA, for example, I can build an ebike from parts or kit, and have a 1,000 W motor, though I am still limited to a max speed of 20 mph from the power system.

Bob Hoboken's picture

Your article is spot on in many ways. I ordered the Chinese kit from "the bay" for around 750 shipped. It's a 1kw golden motors hub with 20ah LifePo4 battery. I got around 1 year use out of it before the battery management system (BMS) failed. The battery is just a bunch of cells wrapped up in duct tape. It does work well though when it runs. I am 300 lbs and can get average 25-30 mph. Would recommend TOP of the line tires and tubes though. I had a front blowout at 25 mph and the road rash wasn't pretty. Also, anything handling power (controller / bms) gets hot. Hang those out in the airstream for cooling. Braking is HUGE when you add all the weight and speed to your bike. I honestly don't feel much difference in wheel braking vs disc. In wet weather I'd go disc. I don't have the controller to give regen a try for braking. I don't recommend rear drive given my setup. Adding disc braking is next to impossible and it was a b!tch to get the freewheel cluster to spin after installation. Clearances were tough to obtain given the chain and frame in high gear. If I were to buy another kit from China, I'd go front wheel drive. I'm hoping top tire makers like Schwalbe realize the need for beefier e-bike tires and develop them. Past 25 mph, you really are asking for it if you have a blowout. A helmet is a definate must, gloves and even other padding case you go down.
All that said, I'd not steer away from e-bikes for a second. They are flat out FUN and I've used mine for short commutes to work on a regular basis. Passing up gas stations daily is a joy you simply have to experience for yourself. I plugged in at work after doing the math for my boss (kill a watt meter helps) how little juice my bike drank. My commute was free at that point. I tow my battery in a well built 2 seat kid trailer. Work stuff and stops by the store go into the trailer. Don't rely on a seat post mounted tote for your 20ah battery unless it's welded steel. My very well made aluminum tote broke inside of 3 months.
Final thoughts, I will probably graduate into a small motorcycle simply for the better tires and brakes. A 48-72v motorcycle will have all the speed / range I need to get to work and our company now has charging stations available so again, my commute will be free. I look forward to leaving gas for good !!

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