E-bikes are everywhere these days and are introducing new terminology to the traditional bicycle vernacular that we’re used to. I’ve created this useful glossary of the most important e-bike terms so readers can better understand e-bikes and see past colorful market jargon during their search for some shiny, new wheels.
Whether you’re looking for a refresher or are new to the whole e-bike thing, read through this crash course on all things e-bikes. Welcome class, to E-bikes 101!
Basic E-Bike Terminology
E-Bike Classes
E-bikes are categorized into three classes based on the type of motor assistance and top speed. This is an easy way to know about a bike’s maximum capabilities, acting as a clue to the e-bike’s legality on certain trails or paths.
Class 1: These bikes only have pedal assist. The top speed is 20 mph.
Class 2: Pedal-assist provides a boost up to 20 mph and there is also a throttle mode.
Class 3: Pedal-assist only— the motor has a top speed of 28 mph.
Note: Many high-powered, entry-level e-bikes on the market combine Class 2 and Class 3 capabilities. This means the throttle mode assists up to 20 mph while the pedal-assist levels max out at 28 mph.
Pedal-Assist (PAS)
Pedal-assist means that the motor provides a boost as long as the rider is pedaling. Pedaling faster or harder will increase the level of assistance from the motor— riders can also toggle between the available pedal-assist modes. Compared to using a throttle, pedal-assisted riding offers a more natural-feeling boost of speed that scales with the rider’s own pedaling power. Many European brands and some manufacturers refer to pedal-assist bikes as “pedelecs”.
Drive Modes
Most e-bikes have a small control pad or button near the handlebars that allows riders to change between different levels of pedal assistance. These PAS levels may simply be numbered or have names such as Eco, Sport, or Turbo. Higher-powered modes use more energy from the battery, leading to faster speeds but less range. Some models also come with a Push-assist or Walk mode to facilitate transportation while off of the bike.
E-Bike Motors Explained
Mid-Drive Motor
Named for their central placement between the pedals, mid-drive motors are built into the bottom bracket area of an e-bike. Mid-drive motors’ balanced weight distribution achieves a more natural-feeling boost and extra stability from a lower center of gravity. These motors are typically more efficient and of higher quality than hub motors, including better acceleration and torque.
Hub Motor
Hub motors are integrated into a bike wheel, typically the rear wheel but front hub motors also exist. These simpler motors are popular on entry-level or mid-tier electric bikes as well as conversion kits for traditional bicycles. They are normally less powerful and performance-oriented than mid-drive units.
Torque (Nm)
A rotational force measured in Newton meters (Nm), referring to the peak force the motor can provide. Big torque ratings are most relevant for climbing hills or pulling heavy weight on an e-bike. Lightweight e-bikes have around 35 Nm of torque while higher-powered models can have more than 85 Nm of torque.
Power Rating (watts)
A motor’s power is always listed in watts (W). This nominal rating is the amount of work a motor can provide continuously without overheating. Most e-bikes have a power rating of around 250W but some reach 750W or 1000W. European regulations restrict e-bikes to 250W.
Cadence vs. Torque Sensors
Both types of sensors identify when a rider is pedaling to determine the desired level of assistance. Cadence sensors sense when a rider starts pedaling, acting more like an ON/OFF switch to send a signal to the motor to engage. Torque sensors identify how hard a rider is actually pushing on the pedals, leading to a scaled output of power from the motor for a more natural-feeling boost. Cadence sensors are cheaper than torque sensors.
E-Bike Displays
E-bike displays come in all shapes, sizes, and designs but are typically located near the center of the handlebars to provide easy viewing of metrics like speed, battery life, and PAS level. Some displays are black-and-white while others are full-color. Other e-bikes have no display or offer a compatible mobile application to access settings.
E-Bike Batteries Explained
External vs. Internal Batteries
Batteries on e-bikes are either located inside the downtube or attached to the outside of the frame. Externally mounted batteries are easier to remove for off-bike charging or swapping for a fresh one. Internal batteries, on the other hand, help achieve a sleeker, more streamlined look.
Battery Capacity
A battery’s capacity refers to the total amount of energy stored in the battery. The most comprehensive metric is watt-hours (Wh), or the energy required to power one watt for one hour. Watt-hours are calculated by multiplying voltage (V) by amp-hours (Ah). E-bike batteries range from around 300Wh to 900Wh depending on the range needed and power of the motor. Given the same motor, a higher watt-hours rating means a longer range.
Range
Range describes the distance that the e-bike battery will last on a single charge. The most accurate clue to an e-bike’s range is the battery’s watt-hours, but range is influenced by factors such as pedal assist level, rider weight, and terrain. Due to such variance, many e-bike brands don’t provide a specific range. Watch out for other manufacturers who inflate their e-bike’s range for marketing purposes, too.
E-Bike Parts & Components
Frame Shapes
Many e-bikes are available in two different frame versions: step-thru and high-step. Step-thru (or step-through) has a lower top tube that makes it easier to hop on and off the bike, ideal for smaller riders, recreational users, or cyclists with lower mobility who have a harder time swinging their leg over the frame. High-step or standard frames have typical geometry with a higher top tube. Some bikes are designated as foldable, meaning they have folding hinges in the middle of the frame and handlebars for easier storage or transport.
Suspension
Bike suspension systems absorb shocks and impacts for a smoother, more comfortable ride. Some e-bikes have a front suspension fork and full-suspension models add a rear suspension shock. Almost any type of e-bike can have suspension, but it will add to the overall cost and bike weight.
Disc Brakes
Disc brakes are the standard for e-bikes because of the added power and weight of electric bikes. Compared to rim brakes, disc brakes offer stronger, more reliable stopping performance, especially in wet conditions. Higher-end electric bikes opt for hydraulic brakes over mechanical disc brakes.
Fat Tires
Fat tires are oversized tires that have a width of 4” or more. The huge air volume means they can be run at lower pressures, providing additional traction and shock absorption. Many all-terrain budget e-bikes come with fat tires.
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