eBikes are the hot ticket in cycling. As their performance improves, prices fall and confidence in the technology soars, more and more cyclists are making the investment. Before dropping big bucks on a new bike there are some fundamentals you need to know about.

1) There are the different motor types. Mid-mounted motors offer the most performance, but at a cost.

There are two ebike motor types, “Mid-Mounted” and “Hub Drive”. You are probably wondering what type of ebike motor is right for you? Each has its benefits, but it is generally agreed that Mid-Mounted motors deliver a better cycling experience and Hub Drive motors are more affordable.

Because of where Mid-Motors are located (at the bottom bracket – where the crank arms attach to the chainring) the distribution of weight is more evenly balanced, which is particularly important for mountain biking. The motor applies force through the drivetrain leveraging the gears, which increases efficiency and performance. Torque sensors, used on mid-mounted motor configurations, allow the control system to vary the power output of the motor so if the rider is pedalling gently the motor output is decreased, saving battery charge and giving the extra power a more “natural” feel.

Hub motors by contrast do not apply power to the drivetrain, instead, power is applied independently to the rear or front wheel, depending on where the motor is installed. Some more expensive hub drive motors are geared, but most are not which reduces a motor’s ability to assist on steep inclines and its efficiency at slow speeds.

   

2) Usually, more torque is better.

Torque is a measure of rotational force created by the motor. On a normal bicycle, torque is the force (Newtons) applied to the pedal, multiplied by the distance of the crank arms (Meters). It is essentially the grunt that will pull a bike up a steep incline or accelerate it quickly off the line.

So, how much torque do you need? Electric motor torque ranges vary from 30Nm in entry level Hub drive products to more than 100Nm for the most powerful crank drive (mid-mounted) motors. The more torque a motor can generate the steeper the inclines the bike can climb. 85Nm is a common torque figure for high spec mid-mounted motors designed for mountain biking. Town and commuting bikes typically require less torque.

But torque comes at a premium - torquey motors are more expensive, and, because they’re designed for use on steeper inclines, they require higher capacity batteries… which are more expensive. With that in-mind, if your electric bike is intended to cruise around town or to whiz you along flat or gently undulating countryside and budget is limited, consider a motor with a moderate torque number.

 

3) Choosing the right battery capacity is guesswork. If range is important, opt for the largest capacity battery you can afford.

There are so many factors that determine the range a battery can provide, from the equipment, such as tyre choice and riding position, to environmental factors, like ambient temperature and trail surface. And let’s not forget you, the rider – exertion levels and rider weight are extremely important considerations. Because of that, estimating the battery capacity you’ll need is always an educated guess.

In the UK and EU, the speed to which an electric motor is legally allowed to assist you is restricted to 25kmh (15.5mph). It’s much more likely that motor power will be required to reach that speed in an off-road scenario where the bike tyre has a greater rolling resistance on the trail surface and the uphills are steeper. For these reasons the potential range of a bike off-road is significantly lower than the on-road equivalent.

If you are intending to spend long days riding off-road and you have a high torque motor on the bike, get the largest capacity battery you can afford – 600Wh should be enough for some long and gruelling days in the saddle.

For smaller, less intense riding, like pootling down to the beach or the commute to work, you can save a few bob by opting for a lower capacity battery. A conservative estimate for how much distance can be covered by an ebike on paved surfaces is between 5 and 10 miles for every 100Wh of battery capacity. It’s not failsafe, but it’s a useful estimate for gauging range.

If worst comes to worst and you run out of juice, you can still pedal home!

 

4) It matters how and where the battery is mounted.

Placing the battery on or in a bike’s downtube improves the balance of the bike by keeping the centre of gravity low to the ground and centralised. If the battery sits hidden within the downtube it not only looks nice, but it is also better protected from impact, dirt and moisture. This is an important benefit for bikes intended for off-road use.

External batteries have their advantages, they are typically more affordable, and they can be removed very simply for charging or replacing. External, key-release batteries make a lot of sense for commuters who perhaps need to remove the battery for charging or security purposes.

Rack mounted batteries, secured horizontally above the rear wheel, have benefits too. For elderly or less able cyclists placing the battery slightly higher, at the back of the bike where it is easier to reach and remove, is a gamechanger.

   

5) Control units are getting fancy, but basic is all you really need.

Ebike technology is becoming more and more sophisticated. Top of the range control units by market leaders such as Bosch and Shimano not only communicate basic information such as range, speed and the degree of assistance, but they can also be synced with a smartphone to provide navigation, weather reporting and even fitness metrics. It’s very tempting to choose something fancy, but as smart as the displays are becoming, something basic, which gives control of the pedal assist mode and indicates the range left in the battery, are all you really need.

 

6) There are laws around the use of ebikes.

A cyclist must be 14 years or older to ride an ebike on roads and public ways in the UK. UK law also limits the motor power of pedal assisted electric bikes to 250W and a maximum speed of 25kmh (15.5mph) – that is to say, the maximum speed that the bike is permitted to be assisted to.

Until recently, unlike the rest of the UK, cycling an ebike in Northern Ireland required a license, insurance, and registration. That changed on the 13th of May 2020, when Members of the Legislative Assembly voted unanimously to make it legal to ride an ebike in the country, from the age of 14, without the paperwork, just like the rest of the UK.

   

7) Look after your ebike and you’ll get many years of riding.

Ebikes need a bit more TLC than standard pedal bikes.

Over time the battery capacity declines. When you can no longer get the range you require, you’ll have to replace the battery. The perceived wisdom is that you will need to replace the battery every 2-4 years depending on how often you ride and the conditions you ride in. The half-life of a battery is typically between 500 and 1000 charge cycles.

It’s also important to keep on top of regular bicycle maintenance such as keeping the brakes and shifters adjusted, replacing brake pads and cables as they wear out, cleaning and lubing the drivetrain, greasing the bearings and tightening suspension linkages which are put under enormous strain by these heavy bikes. Except for the electrical components, Ebikes use the same parts as non-powered bikes, which means maintenance can be performed by a trained cycle mechanic or at home by a confident hobbyist.

And, with all that extra torque, riding at higher average speeds and covering more distance you will inevitably go through tyres quicker than you’re used to.