What are they?
An e-bike is a regular bicycle with the addition of an electric motor and battery. The electric motor provides power assistance when the cyclist is pedaling to ease the amount of effort required. The harder you pedal, the more assistance it gives you.
In the UK, an e-bike is road-legal for anyone if they are aged 14 and over, and if the assisted speed is restricted to a generous 15.5mph. They are now a real mode of transport to be considered, not only by the elderly but if you quite simply want to get around quickly efficiently and in a environmentally friendly manner.
Electric Drive Systems
Please note all road legal e-bikes require the rider to physically pedal the bike, the electrical motor offer you assistance, it will not propel the bike without you riding it.
There are 2 main drive systems used, starting with the most basic hub drive whereby one of the wheels will be assisted directly, with the motor in the hub of the wheel. This is used on a lot of the lower end bikes.
Crank (pedal) based system - this is seen by most as the best option. The motor is in the frame, between the pedals and offer assistance to the revolution of the pedals as you pedal, it offers a much more balanced ride.
Range - Usually 30 - 120 miles.
The electric system offers you 'assistance' so the range of the bike will vary wildly on 3 factors
1 - the size and output of the electrical drive system
2 - the mode the rider choices when riding ( economy mode will use much less battery power than high mode )
3 - The terrain & environment the bike is ridden in - if the bike is going up hill into a headwind it will use more battery then the bike going downhill.
Even with the above being taken in consideration you can usually assume with a full charge most electric bike will give you between 30 - 120 miles, depending on the type of electric system it run.
Most Ebikes will charge from empty to full in 4 hours, they use a standard plug, and can be topped up at no detriment to the battery, much like a mobile phone.