E-Bike Glossary - 71 things you need to know about E-bikes

Just when you thought you knew everything there was to know about bikes, along came the e-bike revolution. They are perfect for commuters, leisure riders and businesses wanting to take advantage of the benefits of a micromobility fleet (yes, that’s one of the terms we’ll be defining). But it’s essential that you know what you need to best suit your needs.

Join us on an A to W journey (we couldn’t think of anything for X, Y, or Z) of e-bike terms that cover everything from the different types of e-bikes available to their motors and power

Adapted cycles - Bikes that have been specifically designed to meet the mobility needs of the rider (e.g., tricycles, hand bikes, recumbents, one-handed braking, and adjusted saddles).

After market kit - Components that are used to convert a manual bicycle to an electric bike.

Amp-hours (Ah) - This is related to battery capacity: the more amp-hours, the longer your charge will last (most e-bike batteries offer between 11-14 Ah).

Assist levels - Every e-bike has pre-set assist levels to allow you to choose how much motor assistance you need. Some models offer further personalisation through apps or the onboard screen.

Battery range - This is the number of miles you can expect from a single battery charge on your e-bike. It will vary depending on your bike, battery, and the type of riding you’re doing. But you can normally expect between 20 and 75 miles.

BMS - This stands for Battery Maintenance System, which is an electronic circuit found on advanced batteries. It prevents damage to the battery and prevents safety problems relating to battery overheating and it monitors the charging process.

Bottom bracket - This is the hollow cylindrical tube that connects both pedal cranks, allowing the rider to pedal (see diagram below).

Brake kill switch - A device that turns off the motor when the rider applies the brakes.

Brake sensor - This senses when the rider pulls the brakes, turning off the motor. It also stops the power to the throttle and pedal-assist so you can brake safely.

Brush-type DC motor - This motor uses brushes to create a wear point. Less expensive in terms of control electronics and manufacture.

Brushless DC motor - Longer lasting and more straightforward than a brush-type motor because there are no wear points other than the bearings. More costly in terms of control electronics. Also called a BLDC Motor.

C-rate - This is a unit of measurement that describes how fast a battery can supply current. So, a 1c rate means that the battery can be completely discharged in one hour. Trying to go faster than that will simply not work or might damage the battery. A 2c rate battery can be discharged in 30 minutes, or twice as fast as a 1c rate battery.

 Why is this important? Well, if your e-bike has a 500-watt motor with a 10  Ah battery, and you’re pedalling up a hill that demands 30 amps of energy, it must supply that energy at a 3c rate to allow the motor to do its job. If your battery is only capable of 1c, you’re more than likely going to walking up the hill.

Cable connector - The site where your electric cable pins come together. This needs to be checked regularly to prevent performance issues on the road.

Cadence senor - Located in bottom bracket (see diagram below), this sensor has a series of magnets that engage by the rotation of the cranks and pedals. They communicate with the controller and motor to give you a boost of power.

Cam lock - This clamp keeps your quick release components in one place. Those on the front axle help you remove the front wheel easily for travel or storage.

Cassette - This is the staked selection of gears attached to your rear wheel (see diagram below).

Centre drive - A centre-drive bike mounts the motor in the centre of the bike’s frame. The most modern version supply power to the bicycle chain, so the motor gains the advantage of any available gear options from the rear cassette and derailleur.

Ceramic magnets - These are used in electric motors and are lower in performance and cost than Neodymium magnets.

Class - E-bikes come in three classes:

• Class1 – pedal-assist only. The motor gives assistance up to 20mph
• Class 2 – pedal-assist mode up to 20mph and a throttle-powered mode
• Class 3 – pedal-assist only. The motor assist up to 28mph

Connectors - The fittings that allow the electrical components and wiring to be connected. Often easily unplugged or released.

Controller - The “brain” of an e-bike. It typically acts as a smart connection between the other components on the bike: motor, battery, throttle, and the pedal assist.

Crank arm - This is attached the pedal to the bottom bracket (see diagram below).

Cycle charges - As you'd expect this refers to the battery life - as in how long it lasts before it needs replacing. Most modern lithium-ion e-bike batteries last for between 800-1000 charge cycles (about 3-5 years of consistent use for most cyclists).

Derailleur - This attaches the cassette which moves the bike chain from gear to gear (see diagram below).

Diamond frame - The diamond frame has the front and rear triangles arranged in the shape of a diamond. The top tube often runs almost horizontally, resulting in a high standover.

Direct-drive hub motor - These are the simplest type of hub motor. The magnets are fixed on the inside surface of the hub, and the windings are permanently attached to the axle. When power is applied, the hub rotates around the axle.

Pros: quiet (often silent) operation, few moving parts, and the ability to regenerate power into the battery (because the magnets are always moving over the coils).

Cons: because the motor is always mechanically engaged, there is “cogging,” a drag that can be felt while coasting. They are also larger and heavier than comparable geared hub motors to achieve the same performance.

Disc brakes - These has a metal rotor in the centre of each wheel and are attached to brake pads that allow the e-bike to stop.

Display - The display is attached to the handlebars of the bike and shows you useful information about your electric bike while it is being used. In most cases, this is also where you control the power assistance when riding.

Downtube - The part of the bike frame that faces the underside of the bike and is necessary for supporting the structure of the frame (see diagram below).

EPAC - Acronym for Electrically Assisted Pedal Cycle.

E-bike - The generic term for an electrically powered bicycle.

E-cargo bike - E-cargo bikes (or electric cargo bikes) are designed to carry a load, such as children or bulkier items and are a greener alternative to the car.

Designs designs to accommodate front or back load options. Accessories and attachments are also available to tailor your bike to your individual needs.

Electronic shifting - The gears are controlled electronically with a wired or wireless signal sent to the derailleur. Small batteries provide the necessary power.

Folding bikes - A compact option for those with limited storage space. They’re also great for combining cycle and public transport journeys.

Fork - Part of the bike frame connected to the bike’s head tube and connected to each side of the wheel hub that holds the front wheel on to the bike (see diagram below).

Front drive - A front-drive bike has the hub motor in the front wheel. Not often seen on production e-bikes but is quite common for conversion kits.

Gear ratio - The ratio of the chainring to the rear sprocket. To be able to maintain a steady cadence at different speeds, the gear ratio is adjusted by shifting gears.

Gear-type motor - A hub motor that uses a gear reduction inside the hub shell. Normally a less expensive option that gives good performance but are noisy and have more wear points.

Geared hub motor - These are hub motors built with internal planetary reduction gearing.

Smaller than direct-drive motors, they are more efficient and produce more torque. Plus, they are mechanically disengaged from the bicycle wheel when not powered, so they avoid the coasting drag experienced with direct-drive motors.

Mind you, they tend to be more expensive, noisy, and have moving parts that can wear out.

Head tube - The tube at the front of the bike frame that holds the fork in place and allows the stem and handlebars to be mounted (see diagram below).

Hub motor - Located at the rear hub, they tend to be lighter and more discrete (but usually give out less power) than larger mid-drive motors.

Human electric hybrid - These are e-bikes that allow both human and electric power.

Integrated battery - The battery used to power the electric bike is fully hidden (integrated) within the frame.

Lead acid batteries - Old school batteries used in most light electric vehicles. Although heavy, they are reliable, have excellent discharge and charge capabilities, and are nearly 100% recyclable (also called SVRLA and Pb A or Pb batteries).

Lightweight e-bikes - E-bikes designed for those who might struggle to lift or manage the extra weight.

Lithium-ion - The most used e-bike battery - high-energy density, low self-discharge.

Mechanical shifting - The gear cables connect the shifter and derailleurs to control the gears.

Micromobility - This refers to a range of small, lightweight vehicles operating at speeds typically below 25km/h (15mph), such as e-bikes, electric scooters, electric skateboards, shared bicycle fleets, and electric pedal assisted bicycles.

Mid-drive motor - The motor is integrated into the bottom bracket along with the bike's crank arms. It is the most common set-up as it keeps the weight of the motor low, lowering the bike's centre of gravity to help stability and handling.

Modes/drive modes - These provide different levels of pedal assistance. They are selected using a handlebar-mounted switch. Common modes are Eco (reduced the level of power assist, increasing battery life), Standard/Trail, and Boost/Turbo (increases level of assistance, improving acceleration but reduces battery life).

Newton metre (Nm) - The measure of the power of your e-bike motor (see ‘Torque’).

PAS - Pedal Assist System - the general term that refers to devices that power the motor automatically when you pedal without the need to press a throttle on the handlebars.

Pedal assist - When you pedal, the electric motor engages to assist you with a boost of power. The more you pedal the more the motor helps you.

Pedelec - This is the term used when an electric bike requires the rider to pedal before the motor will run. This term is a shortened combination of the words "Pedal Electric".

POD - Power on Demand - the speed of the motor is controlled only by a throttle. You can still pedal but it's not required to activate the motor.

Power (watts) - Pedal-assist bikes are limited to a power output of 250w by law because it means they can still be classed as bicycles instead of motor vehicles that need licensing and registration.

Push-assist - E-bikes are heavier than standard bikes, so if you need to push it your bike can offer a low-power push-assist mode to make pushing it easier.

Range - This is the distance or time the battery will last on a single charge. However, this will be affected by the weight of the bike, the rider, the terrain (i.e., hilly, or flat), and the drive mode.

Rear drive - A rear-drive bike has the hub motor in the rear wheel and accounts for most production e-bikes.

Regenerative braking - Direct-drive hub motors can recover a small amount of energy back into the battery while the bike is coasting (aka “regen”).

S-Pedelec - The S-Pedelec is a more powerful e-bike that provides support up to 45 km/h and a continuous motor output of up to 500 W. Unlike a Pedelec, they require a licence plate, insurance and driving licence.

Semi-integrated battery - The e-bike battery is partly hidden (integrated) within the frame.

Standover height - The vertical distance from the middle of the top tube to the ground. The larger it is, the more comfortable it is to get on and off the bike.

Step-through frame - The open frame of a step through cycle can help those with limited flexibility to lift their legs over and mount the cycle.

Throttle - A handlebar control system like those on motorcycles or scooters. Normally usually twist-grip, thumb-lever or push-button.

Torque (Nm) - Torque is the turning force that causes the rotation of the rear wheel and is measured in Newton metres (Nm). Most mid-drive motors (class 1 & 3) are rated at 75-90Nm. Smaller mid-drives and hub-mounted motors in lightweight bikes are usually rated at 35-40Nm.

Torque sensor - This is a device that detects and measures the energy applied by pedalling. This is required for PAS systems (see above) and is preferred for Pedelecs of all sorts.

Trapeze frame - In contrast to the diamond frames (see above), the trapeze frame uses a low-slung top tube for easier mounting and dismounting.

Voltage (V) - This is the power flow from the battery to the motor and is usually measured in watt-hours as explained below.

Walk assist - Some e-bikes have a feature called 'walk assist' to help you manoeuvre the bike while you walk. It's particularly useful on steep hills or if you don't have the strength to move the bike as they can be heavy.

Watt-hours (Wh) - This is the measure of overall battery capacity (v x Ah) and describes how big a battery is and how long it will last on one charge. Higher Wh batteries are larger and heavier but last longer. Most class 1 & 3 e-bikes have batteries in the 300-900Wh range. Lightweight e-bikes tend to offer 300-350Wh, while cargo e-bikes are around 630-900Wh.

Added bonus – the anatomy of an e-bike

In the glossary, we threw various terms at you related to the different frame parts of an e-bike. To help you visualise these, below is a diagram that shows you where they all are.

You're now an e-bike expert

If you’re looking for a bit of added help with investing in an e-bike fleet for your business, it’s essential that you understand the basic terms associated with the world of e-bikes.

Armed with your new-found knowledge, you can shop for your e-bike like a pro.