Electric bike guide

What is an electric bike?

According to Wikipedia: "An electric bicycle (e-bike, eBike, etc.) is a motorized bicycle with an integrated electric motor used to assist propulsion". And it's as simple as that, an electric bike is a bike that stores some of the energy in a battery and then directs that energy to a motor to help you with cranking the pedals.

Why should I buy an electric bike?

E-Bike makes cycling less tiring and more fun, especially in challenging weather conditions or during a hilly commute. As a result, people with e-bikes cycle longer routes to a greater variety of destinations which results in health, environmental and financial benefits.

Why not buying an e-bike?

While providing a lot of benefits, extra equipment comes with an additional cost and weight. An e-bike will generally be £500-1000 more expensive and 5-10 kg heavier compared to its regular counterpart.

Battery

The “fuel tank” of your electric bike and one of the most important (and most expensive) components to consider when choosing an e-bike. Typically e-bikes batteries are ranging anywhere between 200 Wh and 700 Wh.

Since it’s very hard to pedal an e-bike with no juice left in the battery you should keep the following in mind:

• “Range anxiety” might be a real issue for smaller batteries when you need to charge it often and can’t go too far from the place where you charge the bike
• Some bikes have non-removable batteries which means you need to be able to bring the whole bike close to the power outlet
• Battery capacity will go down over time. This could be especially pronounced for no-name cell manufacturers as opposed to known brands such as Samsung, Panasonic, etc.

Range

One of the main questions people have in mind when choosing an electric bike is "How far can I cycle on a single charge?".

Unfortunately, there is really no simple answer here as the range depends on many factors:

• Specific to a particular bike: battery capacity, bike's weight, motor efficiency, drivetrain efficiency, type of tyres, etc.

• Specific to a particular ride: assist level, terrain style, rider's weight, head/tail wind, type of surface, etc.

  Manufacturers can claim all sorts of ranges, most of them quite unrealistic even for ideal conditions (we see claimed range to vary anywhere between 3.5 to 35 Miles per 100 Wh, a whopping 10 times difference!). Realistically you should probably expect anywhere between 5 and 10 Miles per 100 Wh (so e.g. a full battery of 400 Wh with an assumed ride efficiency of 7.5 Miles per 100 Wh will last for 7.5*4 = 30 Miles).

Motor

While motors could differ by some parameters they are mostly constrained by a legal limit of the power output of 250W. Hence the main difference is the position of the motor:

• Front/rear wheel hub motor. These are generally cheaper but could feel less natural to drive, cause skewed weight distribution and make it harder to remove corresponding wheels for e.g. tube replacement.
• Mid-drive motor. Allows for a more natural cycling experience and provides better weight distribution but requires a custom frame and crank design so comes with an additional price tag.

Frame type

First, you probably need to decide whether you want a folding bike or not. A folding bike might be very handy if you have limited storage capacity at home or want to take your bike on public transport, but it also comes with some drawbacks as folding bikes are generally heavier and more expensive compared to "regular" electric bikes with comparable features.

Therefore you should probably only buy a folding bike if you need to have one. Otherwise, it's better to look at bikes with a non-foldable frame where you generally have a choice of 3 frame types:

• High step (also known as "crossbar") allows for a somewhat lighter and sturdier frame but makes it harder to hop on/off a bike, especially if you are wearing e.g. a skirt
• Low step (also known as "step-through") makes it much easier to get on/off a bike but renders the frame to be a bit heavier and/or less firm structurally
• Mixte. As the name suggests it's something in-between of high and low step with benefits/drawbacks also being somewhere in the middle

Other things to consider

Brakes

Electric bikes put additional requirements on breaks because they are heavier and you are likely to decelerate from faster speeds. Disc brakes are usually a better choice as they provide superior stopping capabilities and require less maintenance.

Pedalling sensor

There are two main types:

• A cadence sensor is cheaper but only knows the rotation speed of your crank so could be awkward when e.g. starting uphill with the motor not providing enough torque
• A torque sensor is more expensive but also measures the force you are pressing pedals with so the motor could match your effort much better

Control unit

Usually placed on a handlebar and allows you to control assist level, see remaining battery capacity, current speed, etc. Cheaper models use LED lights while more expensive bikes utilize LCD screens.

Locking

Electric bikes are usually quite expensive so it might make sense to think in advance how and where you plan to store yours. Investing in a more expensive and secure lock is also a good idea.

Lights

Lights are essential when travelling in dark conditions so having those pre-installed and connected to a battery by the manufacturer makes it one less problem for you to worry about. We designed a special “commuter-ready” score to make it easier for you to find out if the bike comes with front/rear lights included.

Additional resources

Want to learn more? There are plenty of guides available online, e.g. take a look at which.com, cyclinguk.org or just google electric bike buying guide.