The future is now, and the future is e-bikes - here’s how they work and why you need one in your life

Believe it or not, electric bikes – variously called power assisted bikes, pedelecs and e-bikes – have been around for over 120 years. The first patent was filed in 1895 by an American chap named Ogden Bolton Jnr. And though his original design wasn’t a million miles from the e-bikes of today (it featured a nifty rear hub motor) it’s fair to say they’ve come on a fair bit since then.


New technologies including high-capacity Lithium-ion batteries, powerful crank drive motors and clever sensors that adjust the assist level depending on how hard you pedal, mean that power assisted bikes are travelling further and faster than ever before. They may still be a relatively rare sight in the UK, but trust me, the e-revolution is coming. And you’re going to want to be a part of it.  


From talking to customers, it’s obvious that there’s still some confusion surrounding the rules and regulations governing the usage of e-bikes, and how exactly it is that they work. So let’s start by clearing up a few of the most commonly asked questions.



An e-bike incorporates an electric motor to a traditional bicycle frame to deliver power assisted pedalling. They’re designed to help the travel further and faster with less effort, providing the extra little bit of oomph you need to top out on steep climbs or helping you keep pace with fitter riders. Unlike on a moped there’s no throttle, but you are able to choose from varying assist levels on most models. 


Well, here are five reasons: 


1. Electric bikes are especially useful in hilly areas. They’ll help you transport heavy loads over long distances with relative ease, which for some people can eliminate the need for a car.


2. They’ll deliver you to the office smelling fresh.  And your colleagues will thank you.


3. E-bike owners ride more. Fact. A recent report by the Transport Research Laboratory showed that regular bikes are ridden fewer than 25 times a year, with 46% being used only one or two times a year. In comparison, nearly a third of E-bikes are used at least once a day and 81% of owners use them at least     once a week.


4. The average e-bike costs the user 5p-8p a mile. Compare this to around 40p for the average car and it’s not hard to see why so many people are swapping their traditional bike for a power assisted model.


5. They’re fun! So fun. 



You do. The motor is there to give you a helping hand – it won’t do all the work for you. 


Absolutely not.  


By law, all e-bikes are limited to an assisted speed of 15.5mph. Pedal faster than this and you’ll be moving without any help from the motor.    


The electrics on most e-bikes are completely sealed. So short of being fully immersed in water, the average pedelec can handle the worst of what the weather has to throw at them. 

Types of electric bike


Hybrid e-bikes

The Ridgeback E-Flight Di2 2017 uses Shimano's STEPS E-Bike sysem, and featured hub gears with automatic shift mode. 

The most common type of electric bike. Urban e-bikes are a smart choice for riders in hilly areas and a favourite of commuters (and their colleagues) the world over, as you don’t arrive at the office lathered in sweat.


They typically feature a 350Wh battery with a full-assist range of around 20 miles – more than enough to take you from A-B, even in a big city like London - and enable older riders, who perhaps aren’t quite as fit as they once were, to get around with relative ease. What’s not to love?



The Giant Dirt-E+ 0 2017, with 500Wh lithium-ion battery and Shimano XT 2x 11-dpeed drivetrain.

The 4x4s of the bike world. E-MTBs take the strain out of gruelling uphill slogs, so you can enjoy more time on the downhills.


Electric mountain bikes come as both hardtail and full suspension and are typically equipped with a large, 500Wh battery for all-day riding – because of this though they can be pretty weighty, so it’s advisable to choose a model with ‘walk assist’ mode.


Haters will be haters


And to the haters who think that E-MTBs are cheating, Cycle Surgery Bike Buyer Sam Bannister has these pearls of wisdom: “To say they’re cheating implies there’s something to win. But for me it’s all about the enjoyment of riding a bike. An e-MTB allows you to do more of that, and that can’t be a bad thing.” 


Still not convinced? Check out what Greg Callaghan and Nico Lau had to say about them...



Road e-bikes

Electric road bikes help you to ride harder for longer. | Photo: Giant bikes

Rumour has it that Lance Armstrong rode an electric road bike to victory in the Tour de France no fewer than seven times. So although not 100% ethical in a race situation, they will give you the edge over the rest of the field. Or help you keep pace with that speedy friend for who can’t seem to tell the difference between a relaxed Sunday ride and a time trial event. 


e-Bike battery

E-MTBs typically feature a large capacity 500wh battery, giving you a range of approximately 25 miles on full assist mode. | Photo: Giant bikes


The range of an electric bike is determined by the capacity of its battery: more power stored equals a greater number of power assisted miles. Some manufacturer will give a power rating in Wh – Watt hours – and some in Ah – Amp hours. But it’s easy enough to convert between though two and compare across brands. To go from Ah to Wh take the Ah capacity and times it by the battery’s rated voltage (usually 36V); for the reverse simply divide Wh by rated voltage.


Brands will sometimes specify a battery’s range in miles, but take this number with a pinch of salt as variables such as headwind, hills, tyre pressure, increased weight on the bike and speed will all affect performance.


As a guide - and for a conservative estimate - divide a battery’s capacity in Watt hours by 20 to get a rough idea of the number of miles you’ll get out of it. So, for example, you can expect to get at least 18 miles from a 360Wh (36v 10Ah) battery using full assist mode.


Bikes with a LCD display will show an updated range as you ride, so you know exactly how much juice you have left in the tank.


Batteries hold less charge as they naturally degrade over time.  


All of our electric bikes use top-of-the-range lithium-ion batteries, which are typically rated to last between 800 and 1000 full charge cycles - but with careful usage it is possible to prolong their lifespan.


The key is to avoid letting them discharge fully before recharging, and ideally to recharge before capacity drops below 50%.


An e-bike battery can be charged from any mains power sockets and most bikes allow you to remove the battery from the frame. Charging times vary depending on the type of battery and the efficiency of the charger, but you can expect a modern battery to recharge fully in three to four hour. 

Motors - crank drive vs hub drive

E-bike motors come mounted on either the wheel hub or the crank drive. And although crank drive motors are widely recognised as the superior of the two, there are advantages and disadvantages to both.


e-Bike hub drive motor

Hub drive motors are usually attached to the front wheel and offer a cheaper alternative to crank drive.

Hub drive are by far the most common type of motor on electric bikes for the simple reason that they are cheaper to produce and easier to fit than crank drive motors. 


The advantages of a hub motor are:

  • Relatively simple in design, so require little in the way of maintenance.
  • Should they require maintenance, they are easily accessible.
  • Cheaper than crank drive motors and more than capable on flat terrain. 


The disadvantages of a hub motor are:

  • Can only deliver full power at one speed, so tend to struggle on steep terrain.
  • Draw a high load at low speeds, which flattens the battery more quickly. To travel efficiently you must maintain a constant speed.  


e-Bike mid drive motor

Crank drive motors typically feature a sensor which measures speed and cadence and adjusts the assists level accordingly. | Photo: Ridgeback

A crank drive motor - sometimes referred to as mid drive - replaces a bike’s crank set, delivering power directly to the chain. By piggy-backing on the bike’s gears, the motor is able to maintain its optimal RPM, even on steep climbs. This allows for a more efficient power transfer, which means that the motor itself can be smaller and, therefore, the bike lighter.


Crank drives place increased pressure on the drive chain. This can cause problems where an electric bike uses regular components, but eGroups from reputable brands, such as the Shimano STEPS system, will include a crankarm, chainring and chain built to cope with the extra strain. 


The advantages of a crank drive motor are:

  • More efficient than hub drive.
  • Many feature a sensor that detects how hard you’re pedalling and adjusts the assist level accordingly. This can help you to ride more efficiently and improve the bike’s range.
  • Excellent for hill climbing – all electric MTBs use a crank drive motor.
  • Mounted centrally and low on the bike, making for an improved centre of gravity and better handling.

The disadvantages of a crank drive motor are:

  • More expensive than hub drive and need to be returned to the manufacturer for repair. 

Varying assist levels

On most modern electric bikes you’re able to choose between three or four different assist levels which dictate how much help you get from the motor. These are selectable either from a basic switch or, on more sophisticated models, a handlebar computer, which will also give you handy readouts like speed, distance travelled and battery life.

Electric bike varying assist level selector

An LCD screen lets you know exactly how much juice you have left in the tank. | Photo: Ridgeback

The higher the assist level; the shorter the bike’s range. So on longer journeys it’s best to select a low level and dial it up as and when you need a bit of extra help.


Because of all the extra technology they carry, e-bikes weigh considerably more than regular bikes, with some (usually e-MTBS) weighing well in excess of 20kg. This can pose quite a problem when it comes to pushing the bike about - so many models feature a nifty ‘walk assist’ mode, which engages the motor at a low level to relieve some of the strain without draining the battery. 

Servicing an electric bike

There’s a common misconception with electric bikes that they’re liable to fall apart at any moment, and require regular and expensive servicing to keep them running smoothly – this simply isn’t the case. A well built e-bike from a reputable brand shouldn’t take any more up-keep than a regular bike. So that means periodic servicing of the bike’s mechanical parts – gearing, brakes, headset etc.


When it comes to the electrics, our trained mechanics are able to run diagnostic checks on the e-Group and replace faulty sensors or switches. But manufacturers insist that a faulty motor unit or battery is returned to them for repair.


You can find details on the servicing options we offer HERE

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