Electric Bikes Buyer’s Guide
First of all, what is an “electric bike”?
Undoubtedly the future of modern cycling, the electric bike (also known as an e-bike) is a bicycle integrated with an electric motor which is used to power the vehicle. They employ a combination of pedal and electric power to craft an easier and more enjoyable riding experience. When the rider pedals, the electric motor kicks in and does some of the work, either automatically or on the rider’s demand. Imagine biking 30 miles to and from work at 20 mph without breaking a sweat- electric bikes offer just that, so their demand just keeps on growing, as more and more people realise the benefits that are obtained through this product.
They are an opportunity to get fitter: electric bikes make journeys, particularly those involving hills, less daunting than they would be on the old, conventional bike; resulting in the more regular use of your electric bicycle than using a normal one. And even power-assisted cycling is much better for you than no exercise at all! Also, the assistance provided by an electric bicycle will extend the range that you’re able to cycle before you get tired, making it an option for journeys that you may formerly had only considered doing by car. Through this, it is apparent how electric bikes really open up the world of cycling to a greater ranger of potential and existing cycling enthusiasts and can help to change the way that we use our bikes for the likes of commuting, exercise, business or just purely pleasure. These environmentally electric bikes emit zero combustion by-products and are classified as zero emission vehicles which is great for the environment, but that’s not all…
Being cheap to run: they may even save you money. In day-to-day use, it only costs a few pence to fully charge the battery on an electric bike. Of course, there is the possible cost of repairs to the motor and that the battery eventually wears out; but, with every journey you take by bicycle, leaving your car at home, a huge amount of petrol money is saved, essentially putting money back into your pocket- this being said before you’ve even started to look for somewhere to park your car. Other perks include the lack of tax, insurance, MOT or congestion charges: electric bikes are cost effective!
Avoid extortionate petrol prices: with the significantly rising cost of fuel, with an electric bike your only worry is finding a mains socket. Once you’ve found one all you have to do is plug in, wait a bit, then you’re ready to go!
Less exertion and less sweat: less effort is required through riding an electric bicycle versus a conventional bike, especially up hills or into headwind, so you’re less likely to end up at work all sweaty and flustered.
A quiet ride: unlike mopeds and scooters with their noisy engines, electric bikes have almost silent motors, meaning that you can enjoy the sounds of your surroundings – and you’re more likely to hear danger before it gets too close.
Which electric bike is the one for me?
Before you purchase a bike you have to think about what you will be using it for. There are many types of electric bikes available, so it is important you get the correct one; styles of electric bike available range from fold-ups right through to retro styles and hybrids.
What to consider when buying an electric bike
It’s the motor that provides the powered assistance within an electric bike. Over time the motors used on electric bikes have improved significantly in regards to their size, weight, noise, reliability and performance. As with batteries, it’s important to ensure that you are purchasing an electric bike with a good quality motor as this is an integral component of your electric bike.
Motor size: The legal maximum size of an electric bike motor in the UK that is going to be used on the public roads is 250W. If an electric bike is going to be used solely off road on private property you do maintain the flexibility to fit a larger motor however.
Pedelec or twist-n-go?
There are two mains types of electric bike.
The most common is what has adopted the term, a ‘Pedelec’. This type of system monitors the rider pedalling and automatically adds a certain amount of motor assistance – usually depending upon pedalling rate, pedalling force and bike speed (so it knows if you’re struggling and helps as much as possible for instance).
The other kind is a ‘twist-n-go’. This is where a switch is used by the rider to trigger the assistance from the motor. They can either be simple on/off affairs or a variable twist grip setup. Current regulations only permit the twist-n-go assistance to be delivered if the system detects the rider is pedalling.
Hub or crank motor?
Motor choice falls into two main types. Either it’s mounted in one of the wheels (hub motor assist) or it’s mounted around the pedal area (crank motor assist) at the bottom of the frame.
Crank motors are sometimes used by manufacturers and are positioned in a purpose built assembly around the pedal area of the bike. From a performance point of view there isn’t much to differentiate them from a good rear hub motor as they are very well positioned, regarding weight distribution. An issue with crank motors are the expense they hold to replace or repair them. Typically, crank assist bikes have a reputation for dealing well with steep hills, but can be a little on the noisy side depending upon the brand and type.
Hub motors are the most commonly used type of motor on electric bikes and provide the required power directly to the wheel itself. The hub motor is fitted in the centre point of one of the wheels which looks both aesthetically good as it’s in a space that is not normally used on the bike and also means that any maintenance can easily be done i.e. to replace it all you have to do is remove the bike wheel. Hub motors are most often positioned in the rear wheel. Hub motors in the front wheel can cause poorer handling as there is not much weight pushing down on the front wheel and so there can be a tendency for the front wheel to feel unresponsive and to slip a bit. These tend to be very quiet but may not handle hills as well as crank assist systems. The main difference between the two motors is how narrow the hub motor has become over the last few years as technology moves on, which has seen the bicycling industry’s application of existing technology from other markets evolving. This has then fuelled advancements of the hub motor systems to cope well with hills and the crank assist systems to now be almost silent, more similarly to the hub motor.
Choosing a good battery is crucial to getting the most out of your electric bike.
Battery size: A bigger battery means more weight which will consequently contribute to making the bike heavier and less efficient. This creates a bit of a balancing act between getting a battery that is powerful enough for your requirements but doesn’t either look bad on the bike or weigh too much.
Battery capacity: the bigger the battery capacity, the further you will be capable of travelling on your electric bike. The capacity of the battery is its ability to store energy which can then be used to power the bike’s motor.
Battery type: There are various types of batteries available, the main two being nickel or lithium based. Nickel Metal Hydride (NiMH) is a well proven and established battery type, although it doesn’t have the same energy storage capacity per kilogram as most lithium batteries, it is very easy to predict its service life, and is cheaper. Lithium based batteries come in quite a few types, such as Lithium Ion (Li Ion), Lithium iron phosphate (LiFePO4), Lithium Polymer (LiPo), Lithium Titanate (Li2TiO3) etc. What they all have in common is a high energy storage capacity per kilogram than more conventional battery types – this helps make e-bikes either lighter, or the same weight with more range when compared to other battery types.
Nickel (Ni-Cad and NiMh): It is only occasionally that you will discover electric bikes in the UK that use Nickel based batteries. These batteries are more expensive than Lead Acid batteries, but are lighter and will last for up to 400 charge/discharge cycles. An acknowledged problem of nickel based batteries is their affliction from memory effect. This means that the battery fails to deliver its original full capacity as it ‘remembers’ previous part charge levels. This problem can be solved but sometimes it is worth avoiding all together in terms of desire for efficiency.
Lithium (Li-ion and Li-Po): Lithium batteries are regarded as the latest and best batteries for electric bikes. They are where the most development money is being invested. There are two main types of lithium battery currently used – Lithium Ion and Lithium Polymer. Lithium Ion (Li-ion) batteries use slightly older Lithium technology than Li-Po batteries. Even still, they have significant benefits over both Lead Acid and Nickel based batteries. They are light, and do not suffer from memory effect and last for about 500 full charge/discharge cycles.
Lithium Polymer (Li-Po): batteries are the latest lithium battery technology. They offer a large number of advantages over Li-ion and the nickel based batteries. The key advantage of Li-Po batteries is that they last for around 1,000 full charge/discharge cycles. In addition, their overall environmental impact is lower than the other types of battery as well as being significantly lighter.
Battery position: an important consideration is where the battery is situated on the bike. There are two main areas where batteries are usually positioned on electric bikes: the rear pannier and seat tube.
Some electric bike manufacturers use the rear pannier to position the battery in either a horizontal manner above the rear pannier and alternatively hanging it vertically down the side of the pannier. Although this position may seem a rational utilization of bike space, the weight of the battery could counteract this and may cause the bike to handle badly. Additionally, the battery lying flat of the pannier it may sometimes work its way loose from its electrical connections, as well as rattling.
Attaching the battery to either the front or the rear of the seat tube (the part of the frame that the seat resides) is the preferred position for many manufacturers. As the battery is positioned vertically it means that the battery always sits firm in its connections. Also the weight of the battery is positioned on the bike where impact is minimal – directly under the rider. This position may also look better as the bike tends to look more like a conventional push bike and not so obviously an electric bike.
Electric bikes are essentially standard pedal cycles with the additional benefit of having electrical power. It is vital that when you process your decision on which electric bike to buy that you don’t just look at the motor and the battery but also all of the components that make up the rest of the bike to ensure that it’s a quality build. Look for branded components as this makes servicing, replacement and upgrading easier. The quality of these components will also have a big impact on the overall weight of the bike which is another important consideration.
The bike frame: a core component of any and every bike. Carbon is the ultimate lightweight material for frames. The downside to this is that it is very expensive. Aluminium frames are becoming increasingly popular as they are both lightweight and also more reasonably priced than carbon frames. The best aluminium frames will be marked as ‘Alloy 6061’. Steel frames are used by some manufacturers; but tend to be on lower specification bikes as steel is cheaper and heavier than aluminium or carbon although it is very strong.
Gears: need to be simple and easy to use, and if they’re from a reputable brand like Shimano or SRAM it’ll make servicing and parts replacement in the future a whole lot easier. As these brands have a large model range, you must ensure that you are getting gears that match the overall specification of the bike. For example, a high specification bike with Shimano gears should have high specification Shimano gears. Asking for more gears on an electric bike might confuse some people– isn’t the whole point that they’re supposed to do the work for you? If they were motorbikes then yes. But they’re not, and UK law dictates that you can’t be given any more than 200 watts of extra power. So you’re still going to have to pedal, and you’re generally going to have to put in a bit of effort doing it too.
Wheels: Reinforced aluminium wheels are both lightweight and strong. Puncture proof tyres are also a useful addition. Good tyre brands are Kenda, Continental and Mavic.
Forks: Suspension forks at the front, which are supposed to take the sting out of hitting bumps (much like the suspension on a car), can be very appealing, but on cheaper electric bikes they’re just a lump of extra weight that you don’t need when riding on roads and cycle paths. Decent suspension forks cost upwards of £500. Adding that to the price of the electrics and the rest of the bike, and you can see why the forks found on £1,000 e-bikes aren’t really worth having. Some electric bikes will have suspension built into the front forks. This can be great if you are cycling over rough terrain, however, if you are generally cycling on roads it’s probably something you can do without as they add extra weight to the bike. Good brands, however, are RockShox, RST and Fox.
Accessories: Full mudguards, puncture-proof tyres, integral lights, a rack, luggage straps, side-stands, chain guards and so on all add up to a bike being easier to just jump on, regardless of the weather. Integrated lights are included on some electric bikes. These can be very useful as they are powered directly from the bike’s battery thus requiring no batteries and can be switched on and off from a switch mounted on the handlebars, so they’re very easy to use.
In Great Britain, electric bikes are covered by the Electrically Assisted Pedal Cycles Regulations. These state that:
- The motor must not be able to propel the bike when it’s going faster than 15mph. You can still pedal above this, as on a normal bike – the motor will kick back in when you reach below 15mph again
- The maximum weight of the bike must not exceed 40kg
- The maximum power output of the motor mustn’t be higher than 200 watts
- You must be 14 years old to ride an electric bike on a public highway