How to choose an electric bike

Questions to ask yourself and your local electric bike shop if you’re looking to purchase an e-bike. This guide has been written by the Electric Transport Shop.

Introduction

So you’ve found the wonderful Pedelecs site and forum. This is good. It means you’re doing the right kind of research into your new electric bike before you part with a fairly large chunk of your hard earned.

No doubt you’ve also googled every permutation of e-bike/electric bike/pedal assist bicycle and followed every thread back and forth about pedelec vs. throttle control, front wheel drive vs. rear wheel drive and brushed vs. brushless motor. If you have I feel your pain. I know exactly how confusing this process can be. I’ve done it. Several years ago now when I first got into the industry I needed to get a feel for what was out there and what products would best suit different types of customer.

Needless to say it was a minefield. So much information and so much of it contradictory! In the intervening years the bikes have become much more sophisticated, more capable; but the process of choosing the ‘right one’ i.e. the right one for you can be just as complicated as ever.

This buyers’ guide will point out some of the questions you should be asking of the bike shop you visit (but hardly anyone ever does), and of yourself before making that commitment.

Part one: Questions to ask yourself:

“What style of bike should I get?”

Ok let’s start with the really basic basics. Before you delve into technical things like batteries and motors, what style of bike do you want to ride?

Some prefer a mountain bike with big fat tyres and flat handlebars. These aren’t just good for off-roading but are bullet-proof commuter bikes too. The 26” wheels and sturdy suspension can take abuse from potholes and kerbs. The stretched out riding position and wide flat handlebars make for a very stable ride. Conversely some people don’t get on with them at all because of the stretched out riding position and flat handlebars! If you find this style uncomfortable try something more ‘sit up and beg’ with an upright position and swept back bars sometimes called ‘Dutch’ style.

Hybrid bikes have bigger wheels and skinnier tyres, still with the wide flat bars but an overall more sporty feel on tarmac. Do you want a bike with a crossbar? It’s not as important as it is with non-electric bikes to have the crossbar, so many blokes are opting for what was once considered a ‘girl’s bike’ with a step-through frame. They make a ton of sense in the electric world as they’re easier to get on and off (especially if you’ve got panniers) and the additional frame flex makes the ride really comfortable. Try a few styles out if you’re unsure, and keep an open mind. Just because you had a mountain bike before and didn’t like it, doesn’t mean you’ll hate all of them. Every bike make and model feels different to ride.

“Front wheel drive, rear wheel drive or crank drive?”

I am going to really upset the entire internet now by letting you into a secret about electric bike motor placement: For most people it doesn’t matter!

If it’s a decent bike with an efficient motor it will work just fine regardless of where they stuck the rotating bit. But just to stem the flow of comments that statement is bound to provoke, let me very briefly go into the pros and cons for each system.

Rear wheel drive means you are sitting more or less over the drive wheel. This gives you great traction. This is good in slippery conditions, but because the battery is often near the back of the bike as well it can make it a bit back heavy for carrying.

Front wheel drive means that when you’re pedalling there is drive to the back (from your pedalling) and drive to the front (from the motor) so you’re all wheel drive. This makes the bike feel more stable. You’ll hear talk on the forums about front wheel motors being prone to wheel spin but this only applies to bikes with poor control systems that don’t give the ride enough progressive control over the power. Good front wheel drive bikes are great in all conditions.

Having a mid/crank drive (whatever you want to call it is fine) system means the centre of gravity is lower and in the middle of the bike for better handling. Putting the motor on the crank means you can use the bike’s own gears if it struggles on the hills. But you can’t fit a throttle (on most, although some crank drive systems are starting to appear with throttle control now) and they’re usually torque sensored so you can’t operate the motor unless you’re already pedaling yourself.

The best advice is to try a few systems out and see which one you like best. If you can’t pedal (or don’t want to) then don’t go for a crank drive, but otherwise the choice is pretty open. The build quality and efficiency of your motor is much more important than it’s placement but shhhh! – Don’t tell the rest of the internet. They’ll have to go back to debating Mac Vs Windows instead.

“How far do I really need to go?”

These days some high energy density lithium batteries are capable of doing 50 miles or even more on a single charge. Many adverts for electric bikes use range as a selling point – more is better, right? Well, not necessarily. Batteries with a bigger range are heavier and more expensive. If you need the range it’s totally worth it. But if you only use the bike less than 5 miles a day why would you spend the extra money and lug around the extra weight?

As a caveat to that I would just add though, that while you shouldn’t go range crazy when selecting a battery, make sure it will do a bit more than you need. If you do 20 miles a day and your battery does 20 miles when new, remember that range will drop slightly as the battery gets older. Get a battery that will do at least 25% more than you need so as the battery gets older it will still get you home. Battery range is also affected by temperature, hills, wind, rider weight and luggage.

But often overlooked is tyre pressure. Nice hard tyres means lower rolling resistance and that means the battery uses less of its power to push you along. Keeping the bike well maintained generally will also make a difference. If the brakes, mudguard stays etc. are rubbing on the wheels then clearly this will dramatically reduce how far it will go in between charges.

“What am I going to carry with me?”

Whether you’re commuting or touring you’ll need somewhere to put your waterproofs, lock, maybe a laptop or some cheese and pickle sandwiches. Do you want to carry all of that in a ruck sack or do you want to let the bike take the strain? Consider something with a pannier rack (or at least provision to have one fitted). I always prefer to load the bike rather than myself. It’s much more relaxing. Bear in mind some rack-mounted battery systems don’t use standard pannier rails so might not accept all panniers, forcing you to buy proprietary ones from the manufacturer. These might be fine for what you need but you won’t be able to shop around to find alternatives and they might not be exactly right for what you want.

“Am I likely to be going up hills?”

All hills are not created equally. Neither are e-bikes. Therefore it is important to get a bike that is capable of getting you up the steepest hill you are likely to encounter. Crank drive systems behave very differently on the hills to hub drive systems. Again you may have read elsewhere (because it’s been misquoted ad-infinitum) that crank drive bikes are better on the hills than hub drives. This is not entirely true, and for some people it is entirely false. Crank drive motors require you to put more effort in to get more out of the motor. In other words the assistance from the motor is proportional to the power you’re providing yourself. Therefore if you’re tired, or can’t push through the pedals much then the bike won’t do well on the hills. The flip side to that is you can use the bike’s gears with the crank motor for the hills. It helps to drop down to a lower gear if you and/or the motor are struggling with the gradient.

With hub drives on the other hand, you can control the motor assistance and your pedaling independently. So long as the motor has the capability of getting up the slope you can pedal as much or as little as you like and it will still get you to the top. Most good bikes will get up a 10% hill (albeit it slowly for some), some will get up a 15% slope and some of the more bikes will do 25% and steeper. Bare in mind though that if they are flying up a 25% gradient without slowing, they’re probably not road legal! Which brings me on to my next question…

“Where am I going to ride the bike?”

If you are going to be using the bike on public roads then there are a few legal considerations you need to be aware of.

The bikes must have a top electrically-assisted speed of no more than 25 kph. This works out to around 15.6 mph. You can pedal the bike faster than this if you’ve got the legs for it but the motor can’t still be pushing you along beyond this point.

The bike must weigh less than 40kgs (at the time of writing although this limit is set to be lifted by the DfT after 2016) and the nominal power output can’t exceed 250 watts. If you are using it off road no such restrictions apply and you can go for something a little more hairy chested. 30mph is easily on the cards, as is much better hill climbing performance. It is very easy to go beyond 30mph but frankly it’s still a push bike – you’d have to be a very special kind of lunatic to want to be heading north of this speed with bicycle brakes, bicycle tyres etc. Besides, ultimate top speed is less important off road than torque. Being able to wheelie over obstacles, power up hills and accelerate out of tight turns is where it’s at. For the average commuter or leisure rider these are not considerations to spend to long on.

That being said there is a glimmer of hope for UK users who want to go a bit quicker. Many European countries have a licensed category of e-bikes capable of 45kph (28mph). They’re called speed pedelecs or s-pedelecs and you need to fix a small identification plate to the bike (like a number plate) and carry insurance. In the UK the British Electric Bicycle Association (BEBA) are currently lobbying to get this category adopted here.

“Do I need to lift the bike around a lot?”

If so, you’ll want something light. Again consider what you need and don’t need. Is a big battery with 40 miles range absolutely vital or would a lighter one that does 20 miles be okay? The lightest bikes on the market are usually carbon fibre which is expensive (except when it’s cheap in which case avoid it because it will flex like cooked spaghetti after a year or so), or aluminium which is cheaper and more or less ubiquitous. As aluminium bikes tend to be cheaper they can be fitted with cheaper (heavier) components which bring the weight back up. Always try lifting it up when you test ride it to see if you can manage it. A light e-bike is really considered to be anything sub-20kgs. Don’t expect anything much below 15kgs regardless of price point at the time of writing.

That being said, materials technology marches ever onwards so if you’re reading this 5 years after it was written then who knows what will be achievable. Another option for light weight is a folding bike. Most don’t ride as well or go as far but there’s less to them so even my steel-framed electric Brompton Sparticle with a heavy Carradice canvas hold-all on the front comes in at just 18.8kgs including the battery. Some people just don’t get on with small wheeled bikes but most can get the hang of them quickly enough. If you’re considering one try a few before you buy. There is probably more difference in ride quality between folding bikes than any other category.

“How much do I want to /can I pedal?”

Some people want to ride their electric bike just like their non-electric bike – or at least the way they used to ride it 20 years ago! In other words they want to pedal. They just want to have a bit of assistance on the hills. If this is you then the choices are pretty wide. You can go for a crank drive motor that requires you to be pedaling to activate the motor drive. This means you get better range out of the same battery because you are helping it with your own pedal power all the time. When you stop it stops. Some systems use what’s called a ‘torque sensor’ to sense the amount of power you are pushing through the pedals and will put more motor power in the harder you pedal.

Part 2: Questions to ask the bike shop.

When you buy a bike (electric or not) you are entering into a relationship with the company you bought it from. You’ll be going back at least once a year for its annual service, but possibly more if you want to add accessories over time, winter tyres, maintenance, or just good advice. Bear this in mind when deciding where to spend your money on day one and you’ll have a much better experience as the years unfold.

First off it’s worth asking some broad questions about their experience with electric bikes. You can do this over the phone before you visit. Then I’ll come on to some more specific questions about the bikes you can ask to help navigate your way to your dream machine.

“Do you have a demonstration model I can try?”

All bikes feel different to ride. The geometry is different, the saddles feel different, the handlebars are different. This goes for all bikes, not just the motorised variety. Now throw front, rear and crank drive into the mix. Can you work out without trying them which one you want? All 36 volt, all well reviewed, all lithium batteries. It’s only when you ride them that one will feel more ‘right’ than the others. Sometimes it’s a simple thing; you may just prefer the gears on one of them or it might be more comfortable. Sometimes the decision is less tangible; you just prefer it. I often find when getting people to test a few bikes that after they’ve ridden them all there will be one they either go back and sit on, or stand by or hold onto. I’m sure it’s subconscious, but a pound to a penny that’s the bike they’ll end up buying. If you ring up a shop and they don’t have demo bikes, and won’t get them in for you then move on to someone else.

“How long have you been selling electric bikes?”

If you’re looking for after-sales care then finding out how broad a shop’s range of e-bikes is and how long they’ve been selling them can be insightful. Electric bike sales are growing faster than any other sector of the cycle industry at the moment. Unsurprisingly many bike shops have started to get a few in hoping to attract a broader customer base. Great. All for that, but what happens if you need a repair done? Can they look at any electric bike fault, diagnose it and repair it? With a company that has lots of electric bikes in their range there’s a good chance they’ll know how to fix most problems quickly and at minimum cost.

“What’s the range/torque/power/motor type of the bike?”

Basically ask them some technical questions. They should be able to tell you the answer to most things about the bikes they sell off the bat. If it’s a new product line they should at least show they understand the question and be able to go and find you the answer. If they quote the manufacturer’s stated range (which will almost certainly be wildly optimistic) make a mental note that this is either unfamiliarity with the bike in real-world situations or sharp salesmanship. I’ve done mystery shopping before and asked staff very straight forward questions about the possible range of the battery or if it’s 36v or 24v and they simply didn’t know. Now imagine they’re the people who are going to service and maintain your bike over the next few years.

So when you’re happy that the shop has demo bikes and a reasonable level of knowledge and capability these are some questions you can ask in store. I’m not going to list ‘how far does it go on a charge?’ or does it have a throttle?’ as these are questions you will have already thought to ask. Pretty much everyone asks these. Here are some questions that few ask, but they should!

“What’s the controller like?”

OK not so much of a question to ask out loud this, but one to ask yourself on the test rides. The single most important aspect of how a bike rides is the control unit. So as not to confuse terminology here, I’m not talking about the display unit on the handlebars with buttons on it, or the twist grip throttle. The control unit is the computer circuitry that controls how the motor gets its power. It controls how progressive that power is, how much torque you get on start up, how responsive the throttle is. Two bikes with the same battery and motor will feel completely different with different controllers. Think about how the motor kicks in when you start to pedal, or turn the throttle. Is it pleasing? Is it laggy or unresponsive? Is it too sharp and snatchy? This is all the controller at work. Another prime reason for trying stuff out before you buy it as there’s no way of telling by looking at the sales blurb on a company website.

“Is it EN19154 certified and can you show me the certificate?”

EN19154 is the European standard that governs electric power assisted cycles (EPACs in Euro-jargon). It’s a 36 page standard governing everything from power (250 watts) to speed (25kph). But it also covers things that not many people know about, such as electromagnetic emissions. In other words interference with things like mobile phones, and more importantly pace-makers. If you have a pace-maker fitted (which may be the reason you’re looking for an electric bike in the first place), the EN19154 certificate will show that it has been tested and won’t cause the pace-maker to misbehave. I’m no doctor but I am assuming a misbehaving pace-maker would be a bad thing. Check that they can show you the physical document. Don’t just take their word for it.

“Is the Battery UN38.3 certified?”

If not it cannot be legally handled in the UK and why is someone selling an uncertified lithium battery? You’d be surprised how often we hear of unapproved batteries coming in from places like China. The problem is you can’t legally move them. The regulations around battery movement are pretty tight these days and you need to have the right certificate and the right box to transport them in. If it doesn’t have these and you want to send it in for repair, how are you going to do that?

“How easy is it to change one of the handlebar components if the bike falls over?”

Why couldn’t the bicycle stand up by itself? Because it was two tyred. Okay it’s an old joke but the point is bikes fall over sometimes. With e-bikes there are essential handlebar controls that can get damaged and need replacing. If the electric bike shop isn’t on your doorstep it will be comforting to know that they have thought about this and guided you to a bike that is easy to support without you bringing it back to them for a simple component change. Electric bike manufacturers that care about the customer’s experience post sale will spend a bit of time and money making the electrical components modular for speedy home and in store repairs.

“Are the nuts, bolts and spokes stainless steel or zinc plated?”

Under £1500 you will find many bikes using zinc plating which looks great in the show room and reduces weight a bit but once in use in British weather it rusts in months, not years. Stainless steel looks great in the show room, and will still look great for the lifetime of the bike.

“Is there a connector on the motorwheel cable to disconnect it if I get a puncture?”

Okay this only applies to hub motor systems, but it’s an important one. Some bikes don’t have a connector on the motor cable so you can’t fully detach the motor wheel from the bike without undoing a bunch of screws around the controller box and then feeding the cable through the frame. Not a job for the faint-hearted and if you want to fix a puncture yourself (or get a local bike shop that doesn’t do electric bikes) to do it you can run into problems. If it’s got a connector, it’s easy.

“Is the battery meter a volt meter or a state of charge meter?”

Sounds a bit technical this one, and for many it won’t matter. But the accuracy of the battery meter for some is important. If you have a medical condition that means you can’t pedal, you really want to know how far you can go before the battery conks out. I won’t go into a long technical explanation as the topic has been discussed at length elsewhere. Suffice it to say a state of charge meter is more accurate than a volt meter type.

“Who makes the battery cells?”

Good lithium batteries are better than they’ve ever been. In fact they’re fantastic. You get years of use and fantastic range out of a battery that weighs just a few kilograms. That being said the battery is usually the most expensive component on the bike and is the only one guaranteed to fail. At the time of writing, in my opinion, Panasonic, Sony and Samsung are making by far the best cells on the market. Bosch batteries are made by Samsung and just make whole battery packs for their own systems (but there are tons of Bosch powered bikes to choose from). Panasonic, Sony and Samsung 18650 cells are turning up in all kinds of bike batteries, and not just at the premium end of the market. It is also true these days that some of the Chinese brand cells are much better than they used to be. If you’re shopping in the sub £1500 category, which let’s face it most of us are, then finding good batteries is one of the hardest things to do. Therefore find out if it’s got a good reputable set of cells in it. There are other good manufacturers but look for that un38.3 certification. Read the forums here and see if people report good or bad things about the batteries. If lots of people are having problems then give them a wide berth. Replacement batteries cost several hundred pounds so you want them to be powerful and last for ages.

“What happens if I have a problem with the bike?”

The answer here should be something like “we’ve got experienced mechanics who can quickly diagnose faults and either have parts on the shelf or can order them quickly for you”

If it’s more like “well you’re covered by the warranty so if anything goes wrong we’ll just send it back” then walk away. Most suppliers won’t just swap out a perfectly good bike because of one small problem. They want to know what part has failed so they can send out that one bit. If the shop tries to send back your whole bike because the handlebar display stopped working, the supplier won’t replace the bike, the shop won’t know how to fix it and it’s anyone’s guess as to when you’ll get it back. Many retailers these days specialise in just electric bikes, or at least have really focused on providing a good offering here with e-bike experts who have been trained up to work on them. Stick to these and you won’t go far wrong and don’t forget to check out the Pedelecs forum for any assistance you need. There are a bunch of very knowledgeable and friendly contributors here that make it their business to help you at every stage.

One last bit of advice would be this: Try before you buy, try before you buy and don’t forget to try before you buy! Motors, controllers, throttles, torque sensors all work together to make up what each bike feels like to ride. It’s like a finger print. It’s unique to that system. Make sure you have a go on a few different bikes. Have fun and buy the one that puts the biggest smile on your face!

Written by The Electric Transport Shop. The Electric Transport Shop are one of the longest established electric bike specialists in the UK. With stores in London, Oxford, York, Cambridge and Bristol. Their own brand ‘Smarta’ holds the Electric Bike World Championship of 2013 and their range of products is one of the largest in Europe.