The Urban Electric Bicycle
E-bikes can be wonderful things, great for older riders, people with really long commutes or who live in cities with lots of hills. Electric bikes are often touted as a way to get more people on to bikes and possibly out of cars.
Many of the e-bikes have 500 watt motors and go 20MPH when the average commuting cyclist goes half that.
In the EU, the de facto standard for an electric bike that can be treated as a bike is:
“Cycles with pedal assistance which are equipped with an auxiliary electric motor having a maximum continuous rated power of 0.25 kW, of which the output is progressively reduced and finally cut off as the vehicle reaches a speed of 25 km/h (16 mph) or if the cyclist stops pedalling.”
Front, Mid or Rear Wheel Drive?
A lot of the lower end e-bikes, like this Coolpeds iBike, are front hub drive. This makes sense; they are the easiest and cheapest to build. But they were known death machines, with too much weight on the front wheel and a tendency to spin out on corners. Obviously a little hub motor in front is not the same thing, but they can still be problematic on corners and on wet pavement, especially if they are more powerful.
Rear Hub installations are more complicated, because of the chain and the gears (orbelt as seen on this Faraday) But they have better traction because of the greater weight on the wheel. It is considered safer, and delivers a smoother ride. But it is harder to fix a flat, and if the battery is also at the rear there may be a tendency to do wheelies.
Then there is the mid drive like this Bosch unit, designed into the frame of the bike, that is becoming more popular. I liked it because the bike is engineered around it, the centre of gravity is really low, it was a pleasure to ride.
Take a look at the Faraday bike or the Maxwell below, where the batteries are built right into the tubes of the bike. It is elegant and it looks like a bike. But it is not necessarily practical; if you ride this bike to work every day, and there are no outlets in the bike storage room to charge an e-bike. That could be a problem. By having a detachable battery you can carry it up to your desk and charge it there.
Pedelec or Throttle?
In Europe, there isn’t much of a choice; almost every bike is a pedelec, where the bike detects either the torque or the cadence of the cyclist pedalling. Because it is all about assisting, not replacing, the pedalling. But the rest of the world doesn’t seem to get it, and since it’s not legislated, buy the bikes with the throttles for that motorcycle feel. The pedelec is safer (one less thing to think about) and provides a bit more exercise, since you do have to pedal.
In the end, we should be learning from Europe, where they have been doing this a lot longer. A big heavy thing with a big motor and a throttle is no longer really a bicycle.
But a European style e-bike is really a bike with a boost, an electric assist. This is what is really needed for people to travel farther, to handle steeper hills, to ride later in life, to play nicely in the bike lanes. They should be bikes, or they should be out in the road with the motorcycles. – treehugger
Read more on this at ebikeschool.com.