Information about eBikes / Electric Bikes
Electric bicycles, or “eBikes” for short, are just normal bicycles with an electric motor attached. The key feature of eBikes is that they are essentially still regular bicycles and can therefore be cycled as normal whenever the power is off.
Electric bikes allow you to go further and faster, or simply to make journeys you otherwise wouldn’t consider. You might be concerned that an eBike would mean you get less exercise, but in fact there is plenty of research to suggest the very opposite, that owners in fact get more exercise! This is because those extra journeys (or extra-long journeys) more than make up for the easier ride. But don’t forget, you can always still pedal along when the motor is running. Rather than a means of avoiding peddling, most people instead use their eBike motor to simply increase their speed and range… or to gain the upper hand on those pesky hills!
Oh, and we could hardly discuss eBike conversions without mentioning all that cash they’ll save you. For example, if you were you to buy a regular electric bike, you would end up maybe a whopping £300-£400 more than were you to convert your existing bike! And what money you do spend starts to look like a really sound investment when you consider the cash you’ll save on the additional journeys you can now make. All tax, insurance and licensing free, of course.
Even if you want to use our eBike conversion fitting service, even after the extra cost of having someone else fit the kit for you, it is still a big discount compared to buying a brand new eBike for £1,000 or more!
Electric bikes tend to come in two main configurations, which are classified according to the type and position of the motor:
Hub Motor: By far the most popular configuration is the hub motor. Here the motor is contained within a compact hub in the front wheel. When you accelerate, the wheel axle stays still and the motor rotates around it, turning the wheel. By peddling, you add pedal power to motor power.
Mid Drive: Electric bikes of this configuration have the motor in the middle of the frame. The motor drives the pedals directly, allowing you to use the bicycle gears to achieve maximum acceleration from your motor (otherwise limited to 250W of power by EU regulations). A mid drive kit therefore gives you excellent acceleration whilst keeping you on the right side of the law!
Hub motors are usually modern “three phase brushless” motors, where a clever “brushless” controller keeps the motor turning without the need for any physical contact to the rotating parts. Old “brushed” motors instead require metallic “brushes” to keep in constant contact with the rotating parts of the motor, which results in lower efficiency and the need for more regular maintenance. Also, most hub motors are internally geared, meaning that they don’t cause any drag when you cycle with and the motor is off. Check out our discussion on regenerative breaking below for more details.
The main disadvantage of the hub motor configuration is that the torque, or turning power, of the motor is constant. Although this torque might be high enough for most purposes, it would be extremely useful if this could be varied. Mid-drive motors overcome this issue by using the bike gears to adjust the torque output of the motor as required. However, the recently developed Xiongda Double Speed Hub Motor, coming soon to Panda Bikes, uses clever internal gearing to give you the best of both worlds. It provides two different modes: a high speed (normal torque) mode for regular cycling on the flat; and a low speed (extra-high torque) mode for tackling hills.
Of course, no matter what motor type or configuration you have, you need somehow to power your motor. Electric bikes run on lithium-ion batteries, which can last for over 800 charge cycles before range starts to decrease appreciably (i.e. to 80% of its original value). However, if you treat your battery well then it will reward you with far better performance. Just take a look at our battery care section to find out how.
Finally, you’ll find that electric bikes often use something called “pedal assist sensors”. These measure how fast the pedals are turning which can then be used to help decide the amount of power the motor should provide. Essentially, the faster you pedal the faster the motor will turn. This ensures that the “electric” part of the electric bike experience is as discreet and easy to use as possible. However, it’s always up to you (set through the controls) how much assistance the motor should provide.
We’re often asked if electric bikes will charge up when going downhill, i.e. do they have regenerate breaking. The answer is no, but there are some very good reasons for this.
Firstly, our hub motors as so-called “zero-drag geared motors”, which means the motor only turns the wheel when it is activated. Put succinctly, when you drive the motor, it turns the wheel; but if you turn the wheel, it won’t drive the motor. The great advantage of this is the complete lack of drag when cycling with the motor off, but the disadvantage is that it’s incompatible with the idea of regenerative breaking. Motors which do allow regenerative breaking, called “direct drive” motors, suffer from precisely the above problem, i.e. they create drag when you cycle (even with the motor off) such that you can’t cycle normally when the battery is empty.
Secondly, regenerative breaking may be great for Formula One cars but it isn’t actually that useful for bicycles unless you are somewhere with a whole of heap of hills. The amount of energy you could perhaps recover, taking into account the energy lost through air resistance and other such effects, is pretty small for an average journey. And although that might increase your range slightly, you’re probably better investing the money in bigger and better batteries.
Essentially, at Panda Bikes we sell only zero-drag geared motors as we believe that your bike should still be usable when the battery is low and that regenerate braking isn’t actually as useful as it might first appear.