What are the different types of electric bike?
Electric bikes are a fast, efficient and environmentally friendly way of travelling. Often quicker and more convenient than using a car in a city, their popularity has exploded recently and there are now electric versions of almost every type of bike and to suit every rider. However, the legalities, options and terminologies can be confusing, so read on for some clarification and explanation.
In the last few years, the various laws and regulations governing the various types of electric bikes and their use in the UK have become much clearer. To be still classified as a bicycle, an electric bike must only provide pedal assistance (not be throttle operated), assistance must be limited to a maximum of 15.5mph / 25kph and the motor can only have a nominal power of 250 watts. Everything else, such as S-Pedelecs or twist-and-go bikes, have a similar status to a moped and must abide by the same laws, thus requiring a license, registration, insurance etc. Only pedal assistance electric bikes can be ridden in cycle lanes and on bridleways, all other forms of electric bikes must abide by the same traffic rules as a moped or motorbike.
At Sigma Sports, we only sell fully legal pedal assistance electric bikes so they can be ridden in exactly the same way as a non-powered bicycle and don’t require a license, registration, insurance or helmet. However, there is still a wide variety of types and styles to choose from, so this guide will help you make the right choice of electric bike for your riding.
The Types of Motor Used in Electric Bikes
The motor that powers an electric bike is usually located in one of two possible places; either in one of the hubs or in the bottom bracket area. There are pros and cons to both:
Hub-based motors tend to be smaller, lighter and less powerful so are often found on commuter or hybrid style bikes although they have also been adopted for some lower-powered road bikes in order to take advantage of their lighter weight. As there is no need to manufacture the frame with room for a motor in it, the frame and the bike can look more subtle and elegant than the alternatives. If the motor is located in the front hub then the steering and traction can be affected a little and, whether positioned front or rear, removing the wheel can be a little more difficult. At slow speeds hub motors can struggle a touch as they drive the wheel directly rather than with the benefit of gearing, but operate better when spinning at higher speeds.
Bottom Bracket Motor
Bikes that site the motor in the bottom bracket area (sometimes called mid-motor or crank motor) have to have a frame that has been designed specifically to house it, so can look bulky and heavy, but as it can be larger than a hub motor it can also be more powerful. Mountain bikes, in particular, utilise this form of motor, but it can also be found in many powerful electric road or gravel bikes as well as some hybrids. As the motor is connected to the crankset, it is more likely to be spinning quickly and efficiently to help drive the bike, but the added torque can cause extra wear on the chain and drivetrain.
The Types of Battery Used in Electric Bikes
Key to an electric bike’s performance and range is its battery. Measured in watt hours (Wh), the bigger the battery’s output, the greater the range that the bike will have, all other things being equal, but this power comes at the cost of size, weight and charge time. Most modern electric bikes use Lithium-Ion batteries as they offer the best performance and range for their weight and don’t need to be fully discharged before recharging. Batteries are usually between 300-700Wh, although some bikes can have additional range extender batteries added to the system for longer rides.
The main location for the battery on an electric bike is either in the downtube of the frame or on a rack at the back of the bike. The rack-mounted option is the simplest for the manufacturer and allows easy access to the battery for removal or recharging but raises the bike’s centre of gravity and means that the rack might not be able to be used for luggage as well. Typically it is less expensive commuter or hybrid style bikes that mount the battery in this way.
The more prevalent battery placement option is to design the bike’s frame around a battery that is mounted in, or forms part of, the downtube; this solution is much neater than rack mounting and keeps the extra weight low down on the frame for better handling. Some of these downtube batteries can be removed from the bike without the need for tools for charging in the house or to save weight if electric assistance isn’t required on a particular ride.
Electric Hybrid Bikes
Whether called hybrids, commuters or town bikes, it is this category of electric bikes that perhaps makes more sense than any other. As cities get more congested and cars become less environmentally acceptable, the ease of using an electric hybrid bike for local trips and errands becomes ever more compelling.
The motor takes the sting out of any hills and also makes it a lot easier to carry shopping or work necessities as well as negating any worry about getting tired and sweaty on the journey. Just as with their non-electric counterparts, a hybrid style bike offers a comfortable riding position with a good view over any traffic along with straight handlebars, a good range of gears and quite likely disc brakes too. Additional practical features such as mudguards, luggage racks (or at least mounts for easy fitment) and even kickstands are usually present, making it quicker, more convenient as well as healthier to use an electric bike for many shorter journeys.
Electric Road Bikes
The typical vision of a lightweight, sleek and svelte road bike doesn’t sit particularly well with the heavy and clunky image of a stereotypical electric bike, but the inexorable march of technology now means that electric road bikes can be light and aesthetically pleasing too. Whilst the motor and battery do inevitable add some weight to the bike, the extra power available more than offsets the gain when the tarmac heads upwards.
As most motors produce a nominal extra 250W, with more available for brief periods, this provides a huge amount of additional power that can really help on hilly rides. Electric road bikes are brilliant for riders struggling to keep up with faster friends and for riders who want to get out into the hills despite age or injury. Their only Achilles heel however is that like all electric bikes in the UK, assistance from the motor stops at 15.5mph / 25kph for legal reasons, thus they may not be quite so helpful on flat, fast rides.
Electric Mountain Bikes
Mountain bikers have really embraced the advantages that adding a battery and a motor to a bike can bring because it largely because it solves the conundrum of whether to take a bike for the downhills or a bike for the climbs. The motor assistance within electric mountain bikes allows long-travel machines with burly downhill components and aggressive, grippy tyres to be ridden uphill just as easily as their lightweight cross-country counterparts and then hammered back down again at full speed. In these circumstances, the electric motor takes the place of an uplift, giving access to far more vertical metres of descending during the ride than would otherwise be possible.
More recently, manufacturers have taken advantage of newer, lighter motor technology and used smaller batteries in more cross-country orientated mountain bikes that allow less fit riders to confidently explore further afield or hillier areas, with some extra assistance when required. The boost of power really helps on steep, technical climbs or in claggy conditions, keeping the ride flowing and more fun.
Electric Gravel Bikes
Electric gravel bikes utilise similar lightweight motor and battery technology to that used in electric road and cross-country mountain bikes. The aim is to provide some assistance on hills or when tired rather than to dominate the whole ride experience and to increase the rider’s confidence so that longer, more difficult rides can be tackled. The additional power also helps keep up with a mixed ability group.
Electric Folding Bikes
A small but important niche, Electric folding bikes might just be the ultimate commuting machines. The added power helps when the trip to the train station is a little further than ideal or when it’s necessary to carry a bag or briefcase, yet all the convenience of its portability and easy storage is retained. There are a few kilograms of extra weight, but as some manufacturer’s separate the battery into a shoulder bag that fastens to the bike when needed, the bike remains light enough to carry.