How to buy electric bike

The power-assisted bike is getting really hot right now, and more and more people are coming to the store for information on e-bikes . Here are some guidelines to help you before your purchase.

History and key figures

The first electric-assisted bicycles (EVA) appeared in the inter-war period but without success. The idea was revived in the 1970s, but the volume, weight and low battery life did not allow the power-assisted bike to develop. Since 2005, thanks in particular to the technological evolution of the batteries, the electric bicycle is in full swing in France.

Principle of operation of an electric bicycle

It is simply a bike equipped with a motor, which can be either at the bottom of the pedal or in the wheels. This engine is powered by a battery that allows the user of the electric bike to be assisted when pedaling.
Generally VAE have 3 to 4 modes of assistance that can regulate the intensity of assistance pedaling. Of course in OFF mode (without assistance), electric bikes can be used like conventional bikes, but heavier than a traditional bike.

In order for an electric bicycle to remain a bicycle under the law, it must comply with the criteria defined by Standard EN15194 :
• The assistance must be cut from 25 Km / h
• Assistance must be cut off when the user stops pedaling
• Engine power rating must not exceed 250 Watts

There are also electric bikes capable of driving up to 45 Km / h . These electric bikes need to be registered, insured and the user must wear a helmet.

The battery, key element of a pedelec

Indeed on an electric bike, the battery is the most expensive and fragile element. You must be very attentive to the quality of it before your purchase. You need to turn to a famous brand battery such as: Bosch, Yamaha, Panasonic, Shimano, Samsung.

The capacity of a battery is expressed in Ampere-hours, Watts and Volts. The amperage indicates the available electricity in your battery and the voltage the voltage of the electric motor of your bike . If you multiply the amperage by the voltage you get in Watts-hours the amount of energy of your battery when it is full.

For example: a battery of 10 amps in 36 Volts has a capacity of 360 Watts-hours (10Ah X 36V = 360 Wh)

To comply with the EN15194 standard your electric bike is electronically clamped at 250 Wh, the surplus power has an effect on greater autonomy.
Amperage is an indicator of battery life and voltage. So the higher the amperage, the greater the autonomy and the higher the voltage, the easier it will be to climb the coast.

It is difficult to give exactly the autonomy in kilometer, because many parameters such as: the weight of the user, the wind, the pressure of the tires, the relief and your force are taken into account during the use of electric bike . For an average course with a little relief, infrequent stops, a user of average weight and a temperature of 15 °, 100 Wh will allow to travel about 20 kms. It is also necessary to take into account the level of assistance selected, the autonomy can thus vary from simple to triple.
A quality battery lasts between 700 and 1000 recharge cycles. A battery gets older and will lose its capacity over time, so your battery should be replaced when it has lost more than 30% capacity.

It is estimated that the recharge cost is a few cents for 50 Kms and 1 € for 1000 Kms . The real consumption of an electric bike is not its electricity consumption but the amortization of your battery.
A poor quality battery will lose its storage capacity much more quickly

Engine :

The motor of an electric bike can be mounted in the rear wheel, in the front wheel or in the crankset.
Let’s look at the advantages and disadvantages of different engine positions on a pedelec .

• Engine in the rear wheel:
Engine assistance positioned in the rear wheel provides the feeling of being propelled. She is intuitive and natural .
During a puncture, the repair can be complicated if you are not handyman because of the presence of electric cables and may require the use of specific tools.

• Engine in the front wheel:
Electric bikes equipped with a motor in the front wheel are entry-level models. They are simple motors from a technological point of view, their price is affordable . In the event of a breakdown (puncture), the front wheel remains easy to dismount and the repair will be done without difficulty.
The presence of the engine in the front wheel weighs down the direction of the bike, so the driving sensation is unnatural. In climbs made slippery by rain for example or in chippings, the feeling of traction can be unpleasant.

• Engine in the pedalboard:

The main advantage of electric bikes equipped with engine in the pedal is that the weight of it is aligned with the center of gravity of the bike . So they are pedelecs very manageable . They are equipped with a torque sensor that provides a progressive assistance according to the effort provided by the user which allows a smooth driving. They are engines of great reliability. And finally in case of puncture, the repair is as easy as for a traditional bike.

The only negative is the price, in fact it takes at least 1400 € / 1500 € for an electric bike equipped with a central engine entry level.
The engine in the crankset outweighed the other two types of mounting. A cyclist who has been riding an electric bike with a motor in the crankset will never return to a wheel motor.

The engine torque

The torque power is expressed in Newtons per meter (Nm). It’s the strength of the engine . The engine torque is between 15 and 85 Nm depending on the electric bike models.

The higher the engine torque, the more easily your electric bike will climb the ribs. Before buying your pedelec it is important to know what your bike is for.

The more terrain you have, the more force your engine needs.

The weight of an electric bike

The weight of e – bikes has largely decreased in recent years but remains higher than a conventional bike. This is an important criterion when choosing your VAE.

It varies between 9 kg for the lightest and 30 kg for the heaviest. But the vast majority is between 17 and 25 kg.

It is difficult for manufacturers to reduce the weight of electric bikes and this often explains the difference in price between two bikes with equal performance. Indeed more a battery or a frame is light more expensive.

A heavier electric bike can also mean more power and therefore less pedaling effort. It all depends on your use, although it’s clear that the more lightweight your pedestal is, the easier it is to handle.

Warranty and service

The vast majority of manufacturers distinguish the warranty of the bike part, the motor and the battery. In general the cycle part is guaranteed between 1 and 5 years and the engine and the battery between 1 and 3 years.
It is important to follow the manufacturer’s recommendations on the booklet provided when you buy your electric bike .
It is important to recharge your battery each month even if you are not using your electric bike.


I hope this article will help you make the right choice of electric bike. Do not forget to subscribe to our newsletter if you have not done so yet, to receive all our technical advice and promotions.