Bicycle Electric Drives Work

"Everything About How Bicycle Electric
  Drives Work,... But Were Afraid To Ask!"

Q. Is it true that only gearheads, nerds, and engineers want to know how bicycle electric drives work?

A. No, although they do love that kind of info. Many normal people, too, want to get an idea of how these work. That way, as they're shopping for an electric assisted bike or a conversion kit, they have some clue as to what they're looking at.

Q. What are the types of bicycle electric drives available today?

A.  The big three of electric drives are friction, chain and gear, and electric bicycle hub motors.

Q. How does friction drive work?

A. With this system, you've got a splined-shaft motor that sits on the tire. The motor makes the wheel spin and the bike go. This type is very economical, but not very powerful. Some of the energy is being wasted due to the friction on the tire. So that takes a toll on the tires. And friction drive is not the best at getting to faster speeds.

Q. What about chain and gear drives?

A. This is a rear wheel drive set up. You've got a motor attached to planetary gears (okay now, no jokes about Uranus….or mine either, for that matter) with belts or chains that connect a gear set. This is where friction raises its ugly head again. Although this sort of drive system can attain fine cruising speeds and has great low end torque, you're still losing energy through the belts and chains. It's also noisy, by electric drive standards.

Q. What's an electric bicycle hub motor?

A. An electric hub motor fits in the center of the wheel and makes the wheel turn. It has an internal gearbox which is what synchronizes the speed of the motor to the speed of the wheel. Hub motors are very popular for a variety of reasons. First of all, it transmits energy with a minimum amount of loss. They aren't vulnerable to wet or gritty conditions because they're sealed. And the lack of chains and belts means less maintenance and quiet operation.

Q. Which type of drive gives the rider the most control?

A. There really is no difference as far as control goes. The only difference is how the power is transmitted to the drive wheel.

Q. What does "power on demand" mean?

A. Power on demand is also referred to a "gear activated" or "throttle activated". It means that the bike can go without any pedaling at all from the rider. The bike, in effect, turns into a scooter.

Q. Is a throttle bike more powerful?

A. Not necessarily. How much power a bike has is related to the wattage and torque ratings of the engine. Wattage in a bicycle electric drive is like horsepower in a car. And just in case you were wondering: 746 watts equal 1 horsepower.

Q. Is it true that with a power on demand bike you never have to pedal?

A. Well, never is a long time. The more a rider pedals, the less drain on the battery. So a cyclist who isn't pedaling just can't go as far or as fast.

Q. What is "pedal activated"?

A. As its name implies, additional power comes from stepping on the pedal. That may not sound very glamorous, but the motor is still way stronger than the average human.

Q. Wow, you really know a lot about bicycle electric drives, don't you?

A. Yes.

Next learn about electric bicycle kits...

Ride With The Wind...
Trey Taylor
Electric Bike Guy

       Bicycle Electric Drives Work