eBike Specs Explained
Power
Battery Watt-hours
Watt-hours are used to measure the batteries capacity and life.
Volts measure the energy power
Amps measure the energy volume
Volts * Amps = Watt-hours
Anything over 1000Wh is a big battery
Bigger batteries give you more range
But add weight and are the biggest cost of an eBike.
Volts
Volts are used in both battery specs and motor specs
The battery and motor are usually the same voltage
A 48V system is the most common
36V systems are used to save weight and cost, but give up some performance
52V and higher are to gain more power and speed.
Controller Amps
More amps for more power, but less range
Less than 20Amps are typical
High performance eBikes are 30+ Amps
Motor Watts
An eBike motor is measure in watts.
750W is typical because of the eBike class specifications
Peak watts are important to understand.
It gives you a burst of power but is not sustainable.
The controller amps has a lot of influence over the power of the motor.
Just because a motor is 500W does not mean it is a low performing eBike.
It's how the battery, motor, controller, gears, wheels and weight are engineered to work together that gives you good performance.
Motor Torque
Measured in Nm
More torque is good for hill climbing.
Anything above 80Nm is a good torque measurement.
Electric mountain bikes have lower wattage mid-drive motors at 350W but more torque at 125Nm because of the gears.
But they are more expensive
An typical fat tire eBike will have a 750W motor with 80Nm of torque.
Motor Type
Geared Hub-Drive
Most common with lower cost and less maintenance.
Today, almost always integrated in the rear wheel
Direct Drive Hub
Similar to a geared hub-drive
But with higher speeds
Lower acceleration
And a little more weight.
Mid-Drive
High performance with less power required, but more expensive.
Mid-drives have the advantage of using the bikes gears with the motor.
Performance
The two most common questions is how fast and how far with the eBike go?
Speed - How fast will an eBike go?
Speed is controlled by the class the eBike is in, which can be adjusted with the controller.
Class 1 & 2 is limited to 20mph
Class 3 is limited to 28mph
Most controllers can be unlocked, which means it'll go as fast as it can.
More watts, volts or amps will make the eBike go faster.
Assuming a 65lb eBike with a 175lb rider in unlocked mode:
- A 48V battery, 500W motor and 15 amp controller will probably do 20-25mph
- A 48V battery, 750W motor and 20 amp controller will probably do 30mph
- A 52V battery, 1800W peak motor with a 30amp controller may reach 40mph
Range - How far will an eBike go?
Range is controlled by the battery, the bikes weight and terrain.
Generally, the bigger the battery the further you can go.
That's why dual batteries are becoming more popular.
Dual batteries are more expensive and heavier, but it kills range anxiety.
Assistance
Electric bikes have two forms of assistance, pedal and throttle assistance.
Pedal assist
Pedal assist is when the motor assists you in pedaling the bike, making it easier to pedal.
Pedal assist usually has 5 levels, each stops assisting at specific speeds.
Level 1 assists a little bit and stops assisting at the lowest speed
Level 5 is all out assist for maximum speed.
Cadence vs Torque Sensor
This sensor tells the eBikes computer how much or how hard you are pedaling.
The computer responds with the appropriate assistance.
Cadence sensors came out first and simply measures how fast you're pedaling.
Torque sensors are newer and are generally considered the better sensor.
The difference is torque sensors measures your effort as well as how fast you're pedaling.
The result is a smoother pedaling assistance feel.
Throttle assist
Throttle assist does not require any pedaling, just push or twist the throttle and you go.
When I say I'm a throttle first rider, that means I'd rather push the throttle instead of pedaling.
Hill Climbing and Acceleration
Like speed, acceleration and hill climbing is influenced by many factors.
The torque of the motor and the gearing have the biggest influence.
A mid-drive has the advantage of using the eBike gears so they don't need as much power to be good at hill climbing or accelerating.
eBikes with rear hub-drives almost always require more power to meet hill climbing and acceleration needs.
Hub-drive eBikes end up weighing more because of the bigger motors and batteries.
Even with the bigger components, hub-drive eBikes are significantly less expensive than mid-drive eBikes.
You can get a decent hub-drive eBike for under $2,000
Mid-drive eBikes start just over $3,000 and go up from there, with a few exceptions.
Comfort Level
Comfort is not really an eBike spec, but it is certainly a factor when considering an eBike.
Front, rear and seat post suspension, fat tires and riding position all contribute to comfort.
Dimensions and Capacity
Weight
Weight influences how a bike feels.
You want a bike that's easy to ride, feels nimble.
The lighter the better.
A light eBike is under 50lbs
Over 80lbs is getting pretty heavy.
Big fat tires and battery size contribute the most to weight.
Seat Height
Above 32" seat height starts to eliminate short riders
It's easier for tall riders to be on a short eBike than a short rider on a tall eBike
Folded dimensions
Folding eBikes are very convenient for people that want to bring eBikes with them.
eBikes for motorhomes are very popular.
The best folding eBikes can fit into a storage container for easier transportation.
Capacity rider & cargo
The best cargo eBikes can carry up to 450lbs counting both the rider and cargo
That's good for multiple passengers or a good grocery run.
Components
Frame
eBikes come in both a step-over or step-thru frame.
The step-thru frame was always considered a girls bike.
Well... not really anymore.
A lot of model come in both step-thru or step-over, it's a common option.
BMX or Moped styles could be considered another type of frame.
They are step-over frames but lower to the ground, more nimble and fun.
My favorite style has a longer bench seat that's great for tall riders or multiple passengers.
Suspension
Suspension on eBikes is all about comfort.
Dual suspension is found on higher end bikes.
A seat post suspension is another option that no many people think about.
Tires
Tires are measured both in height and width.
Fat tires have become more popular lately, which are 3.5" or wider
Another recent trend is 20" tall tires, which lowers the eBike and changes they way it looks.
Gears
Most eBikes only have gears in the rear wheel
7-speeds are the most common
Hub-drive motors do not use the gears, only the rider when pedaling
Mid-drive motors use the gears along with the rider when pedaling
Brakes
Brakes are an important safety item
Hydraulic brakes are considered better than mechanical brakes
The bigger the rotors the more stopping power
Tektro is a widely used brand for brakes
Front and Rear Racks
Not all eBikes come with racks included.
Most front racks are an accessory
The best rear racks are welded as part of the frame for strength
Pay attention to how much weight the rack can carry
Display
Many many different brands
Two things to look for here
How accurate is the display
How bright is the display, especially in the sunlight.
Styles
Categorizing eBikes helps when shopping for an eBike
Most brands offer models in multiple categories
A few only focus on one style of eBike
Moped / BMX
Nimble, strong and fun
Cargo
Built for cargo and/or multiple passengers
City / Cruiser
Enjoy the ride
Commuter
Used to commute
Fat Tire
More of an all around adventure type of eBike
Folding
Take it with you