Every road-legal e-bike in the EU has a 250 W motor. So why do two 250 W bikes climb so differently? Because power is only half the story — where the motor delivers it is the other half.
How a hub motor works
A hub motor is built into the wheel, usually the rear one. It drives the wheel directly.
The consequence: its torque at the wheel is fixed. Your gears change how your legs are geared to the wheel, but they do nothing for the motor. The motor is always in the same "gear" — direct drive.
What that means in practice: strong and smooth on flat ground, quiet, mechanically simple, and cheaper. Then you hit a steep hill, drop into your lowest gear, and discover the motor has not dropped with you. It bogs down, heats up and slows.
How a mid-drive works
A mid-drive sits at the cranks and drives the chainring — the same place your legs put their power in. Its torque therefore passes through the entire drivetrain.
The consequence: your gears multiply the motor's torque exactly as they multiply yours. Drop into a low gear on a climb and the motor becomes dramatically more effective, just as you do.
The L20 3.0 Pro uses a 100 Nm mid-drive; the N1 Pro an 80 Nm Ananda unit; the LE20 cargo bike a 100 Nm mid-drive, which is the only sensible choice for a bike rated to carry 200 kg.
The other differences
Weight distribution
A mid-drive puts its mass low and central, near the bottom bracket. The bike feels balanced and handles more like an ordinary bicycle. A rear hub motor puts several kilos at the back wheel, which makes the tail feel heavy — noticeable when lifting the bike onto a rack.
Drivetrain wear
This is the honest downside of mid-drives. Motor torque plus rider torque both pass through one chain and cassette, so chains stretch faster and cassettes wear sooner. Budget for more frequent chain replacement. A hub motor bypasses the drivetrain entirely, so your chain only sees your own legs.
Repair
Fixing a puncture on a rear hub motor wheel means dealing with motor cables. It is not difficult but it is fiddlier than a normal wheel. Mid-drive bikes have completely ordinary wheels.
Cost
Mid-drives cost more. In our range the step from a hub-motor L20 3.0 Boost to the mid-drive L20 3.0 Pro is about €300 — and that also buys a bigger battery and GPS tracking.
So which should you buy?
Choose a hub motor if: your area is flat or gently rolling, you mostly ride solo without heavy luggage, you want the lowest price for a given battery size, or you want the simplest possible mechanicals.
Choose a mid-drive if: you ride sustained climbs, you carry cargo or passengers, you are a heavier rider, or you want the bike to feel balanced and behave like a bicycle.
The rule of thumb: if your route has a hill you currently dread, buy the mid-drive. If it does not, put the money into battery capacity or better brakes instead.
What about the "boost" button?
Several ENGWE hub-motor bikes have a boost function that releases extra torque on demand — 55 Nm on the EP-2 Boost, 75 Nm on the EP-2 3.0 Boost, 90 Nm on the Engine Pro 3.0 Boost.
This genuinely helps pulling away from a standstill and on short, sharp ramps. It does not change the fundamental limitation: the torque still arrives at the wheel in a fixed ratio. On a long climb, a mid-drive still wins.
And to answer the question people always ask: boost does not make the bike illegal. EN 15194 limits continuous rated power and assisted speed, not torque. Assistance still cuts out at 25 km/h.
Torque sensors are a separate thing
Worth separating, because the two get conflated. Motor position determines how power is delivered to the road. The sensor determines how the bike decides how much to give you.
A cadence sensor detects pedal rotation and applies a fixed amount of help — it feels like a shove. A torque sensor measures how hard you are pushing and scales assistance to match — it feels like your own legs got stronger. You can have either sensor with either motor type, and for everyday riding the sensor arguably affects the experience more.