How is that technically even possible? Why can a motor suddenly become more powerful even though nothing mechanical has been changed? And what are the consequences of more torque for the chain, sprocket, and the entire drivetrain?
Why an OTA update is even possible for e-bikes
Modern e-bike drives are no longer purely mechanical systems. They consist of:
The actual character of the motor is now largely defined by software. The hardware often has power reserves that the manufacturer deliberately releases conservatively.
An OTA update works similarly to smartphones or electric cars:
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The new firmware is downloaded via the app
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The smartphone connects to the bike via Bluetooth
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The motor control receives new parameters
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Torque, assistance, or riding modes are adjusted
The physical motor remains identical – only the control strategy of the electronics is changed.
Why manufacturers often artificially limit motors
An e-bike motor is not always operated at its absolute physical limit. There are several reasons for this:
1. Durability
Higher load means:
Manufacturers deliberately incorporate safety reserves.
2. Noise development
A more aggressively tuned motor can:
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become louder
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vibrate more
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feel rougher
Many systems are therefore throttled for the sake of comfort and smooth running.
3. Battery protection
More torque usually means:
4. Model policy
Software enables manufacturers to offer different performance levels on the same hardware basis.
A motor may technically be capable of 120 Nm, but is delivered with only 85 or 100 Nm, depending on the model.
How an e-bike motor is dimensioned
An electric motor simplified consists of:
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Rotor
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Stator
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Windings
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Magnets
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Power electronics
Crucial for torque are, among other things:
Basically: M = F x r
Torque thus arises from force and lever arm.
In an e-bike motor, the force is generated electromagnetically. More current flow usually means more torque - but only up to certain limits.
The physical limits of an e-bike motor
Even if software can change a lot: physics remains non-negotiable.
Heat development
The biggest limiting factor is usually temperature.
More power generates more waste heat:
P_loss = I^2 x R
This means:
Therefore, modern motors have temperature sensors and protection algorithms.
Material stress
More torque means higher forces on:
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Gears
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Bearings
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Axles
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Freewheels
Particularly compact mid-drive motors already operate with enormous loads in a small space.
Battery limitations
The battery also sets limits:
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maximum current output
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cell chemistry
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internal resistance
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temperature
A motor can only draw as much power as the battery and electronics can deliver.
Why 120 Nm is impressive
For comparison:
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classic trekking e-bikes: 50–75 Nm
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powerful EMTB systems: 85–95 Nm
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120 Nm is already in the range of small motorcycles
The enormous torque is particularly evident:
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on steep climbs
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at low cadence
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when accelerating
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with heavy luggage
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in technical terrain
Cargo bikes and e-MTBs in particular benefit significantly from this.
The downside: More wear and tear
More torque almost always means more stress on the drivetrain.
The chain suffers first
The bicycle chain is one of the most heavily stressed components.
High motor power leads to:
Especially with incorrect shifting under load, the stress increases massively.
Sprockets and cassettes wear out faster
Sprockets are also subjected to greater stress:
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higher surface pressure
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faster tooth wear
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material fatigue
Particularly small sprockets suffer under high torques.
Gears and rear derailleur
More motor power can also be problematic for:
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shift ramps
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derailleur springs
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freewheels
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hub gears
This is why modern systems often integrate so-called "Shift Detection" functions. The motor briefly reduces power when shifting.
Why software is becoming more important than pure hardware today
The trend is clear: The future of modern e-bikes is increasingly software-defined.
Via firmware, it is now possible to change:
The actual "riding experience" is increasingly created by algorithms.
Does more torque automatically mean better riding?
Not necessarily. Extremely high torques can also have disadvantages:
For many riders, harmonious power delivery and fine modulation are more important than maximum Newton meters.
Conclusion: The OTA update shows how digital modern e-bikes have become
The fact that an e-bike system can be configured to 120 Nm via an app impressively demonstrates how heavily software-controlled modern e-bikes have become.
The hardware often possesses considerable power reserves that are only unlocked by firmware. But more torque is never free:
The actual challenge is therefore not just to provide as much power as possible - but to make it permanently controllable, efficient, and reliably usable.
This is precisely where the quality of an e-bike is no longer determined by the motor alone, but increasingly by the software behind it.
