Battery Terminology (what does it all mean?)
Most e-bike battery manufacturers utilise lithium ion technology as this battery system can store a lot of energy, can recharge quickly and doesn't weigh too much. The measurement used to determine the size of an e-bike battery is wattage (abbreviation Wh).
Wattage is the measurement of the amount of electrical power expressed by a battery. In simple terms for e-bike batteries - the higher the wattage the longer the battery will supply power to the motor - thus meaning you can cycle for longer on your e-bike.
We will go into details about the individual manufacturers batteries in the next blog, but to give you an idea - brands such as Shimano and Bosch are producing batteries that range from 300 - 625w. The trade off with battery sizes being that having a bigger battery increases the weight as well as the price!
Please note that a battery with a bigger wattage (Wh) DOES NOT make the power output of the motor higher. These are two separate systems and measurements.
Motor Terminology (even more of 'what does it mean?')
E-bike motors have a little more going on than the batteries so there are a few different measurements to look out for when choosing the correct motor for you.
Our old friend mr Wh returns - only this time he represents something slightly different. If an e-bike comes with a 250wh motor then that means that the maximum power output of the motor is 250wh. Nearly all e-bike motors are regulated to a max of 250wh output power as many countries have made laws to ensure this is the limit. 250wh is a fair bit of power but to put it into perspective -many riders can produce 400-500wh from their own legs! This gives you a good idea of the level of assistance an e-bike motor will give you.
A force that causes something to rotate. (=turn in a circle).
A little more simple to explain than wattage within e-bike terminology. Torque is simply the amount of force that is being applied by the motor to turn the cranks. The higher the torque - the higher the force being applied to the turning of the cranks.
There are a few things to take note of when looking at torque figures from motors. You are likely to see higher torque figures on motors that have been designed specifically for mountain biking and lower Torque Nm on motors designed for hybrid / touring / city bikes. You see lower torque figures on these types of bikes because generally hybrid / touring / city riding is less demanding and involves lesser gradients than your average mountain bike trail.
If you're considering buying an e-bike then you have to seriously think about what type of cycling you will be doing because it will help you to choose a bike with the correct motor for your needs.
An often less talked about feature, but in our eyes an important one is the Q-Factor of an e-bike motor. Simply put, the q-factor is the measurement between the left and right hand pedal cranks. Many earlier e-bikes had really wide q-factors to accommodate the size of the motor (180mm+). This resulted in a wide cycling stance which felt unnatural and alien compared to a standard bike. The modern motors have managed to reduce the q-factor quite considerably resulting in e-bikes that feel much more like standard bikes. Anything between 168-179mm is inline with modern motors q-factors.
Thanks for reading!
We hope you enjoyed the second instalment of our e-bike blog. If you have any questions or suggestions then please get in touch.