Throttle - Rider Control
The throttle is the only drivetrain component you physically interact with. It is your direct control over how much power the motor should deliver, from standstill to full acceleration.
What does the throttle do?
The throttle is the component that converts rider input into an electrical signal the motor controller can interpret. When you twist or press the throttle, the voltage changes and is sent to the controller, which then adjusts motor power.
The throttle gives you direct control over vehicle acceleration and speed. Unlike PAS (Pedal Assist System), which requires pedaling, a throttle can deliver motor power without pedaling at all, just like a throttle grip on a moped or motorcycle.
Hall sensors and signal voltage
Most modern throttles use a Hall sensor to measure throttle position. A Hall sensor is a contactless magnetic sensor that detects magnetic field strength. When you twist or press the throttle, a magnet moves relative to the sensor, changing the field and therefore the measured voltage.
Typically, the throttle works in a voltage range of about 1-4 V:
- Idle (no throttle): The sensor outputs about 1 V (sometimes 0.8-1.2 V depending on model).
- Full throttle: The sensor outputs about 4 V (sometimes 3.8-4.2 V).
- Partial throttle: Voltage varies linearly between these values. 50% throttle ≈ 2.5 V, 75% throttle ≈ 3.25 V, etc.
The motor controller reads this analog voltage signal continuously (many times per second) and translates it into the desired motor power or torque, depending on whether the controller uses torque-based or speed-based control.
Advantages of Hall sensors
- Contactless: No mechanical wear, long service life.
- Reliable: Works in all weather and tolerates dirt and moisture.
- Linear signal: Smooth and predictable response across the full throttle range.
- Fast: No noticeable delay between rider input and signal output.
Types of throttles
There are two main throttle types for e-bikes and two-wheeled EVs: twist throttle and thumb throttle. Both usually use Hall sensors, but differ in how the rider interacts with them.
Twist throttle
Twist throttle is the most common throttle style on motorcycles, mopeds, and electric mopeds. It consists of a grip that rotates around the handlebar, like on a motorcycle. Twist forward (or backward, depending on setup) to accelerate and release to decelerate.
Thumb throttle
Thumb throttle is a small lever you press with your thumb to accelerate. It is mounted on the handlebar, usually on the right side, and activated by pressing the lever forward or down. This is more common on e-bikes intended primarily for assisted pedaling, but also on ATVs and some electric mopeds.
PAS – Pedal Assist System
PAS (Pedal Assist System) is another type of control that is common on traditional e-bikes, especially in Europe. Instead of controlling motor power directly with a throttle, the system detects when you pedal and provides automatic assistance. The harder you pedal, the more help you get from the motor.
PAS systems usually use a cadence sensor (counts pedal revolutions) or a torque sensor (measures how hard you pedal) mounted at the bottom bracket. When the system detects pedaling, the motor activates automatically according to preset assistance levels (e.g. Eco, Normal, Sport).
PAS vs throttle - key differences
Throttle
- Direct control of motor output
- No pedaling required
- Predictable and responsive
- Common on electric mopeds and performance e-bikes
PAS (Pedal Assist)
- Automatic assist while pedaling
- Pedaling required for motor support
- Feel of "amplified" cycling
- Common on traditional e-bikes
Some e-bikes combine both PAS and throttle, so you can choose between pedaling with assist or riding without pedaling. This gives maximum flexibility and lets you pedal for exercise or use throttle control when you want to rest and ride more like a moped.
Legal aspects
In many countries, including Sweden, vehicles with a throttle that can provide power without pedaling are classified as class II mopeds if they exceed certain limits (250 W, 25 km/h). That typically requires registration, insurance, and a helmet. Vehicles with PAS only, limited to 25 km/h and 250 W, are typically classified as e-bikes and usually do not require registration. Always verify local regulations.
GBIKE 1: Twist or thumb throttle - your choice
The GBIKE 1 kit gives you a choice between twist throttle and thumb throttle, both using Hall sensors for reliable linear control. This lets you pick the throttle style that best matches your riding style and preferences.
Hall sensor with linear signal
Regardless of type, the throttle uses a Hall sensor that provides a smooth linear voltage signal from about 1 V (idle) to 4 V (full throttle). This signal is sent to the motor controller, which interprets the signal and applies torque-based control, meaning throttle position directly controls how much torque the motor delivers. This gives predictable, responsive riding without lag or odd cruise-control-like behavior.
Twist or thumb throttle?
Twist throttle is the default choice for many riders because of its larger control range and motorcycle feel, but thumb throttle can be preferable if handlebar space is limited, if you want to combine throttle and braking more easily, or if you simply prefer thumb-actuated control. Both options work equally well technically, so the choice comes down to personal preference and ergonomics.
No PAS - deliberate choice for GBIKE 1
GBIKE 1 does not include a PAS system. This is a deliberate choice for several reasons. First, GBIKE 1 is a high-performance kit (over 250 W) and is not designed for legal road use as a standard e-bike. PAS is mainly valuable for e-bikes intended for traffic rules where pedaling is required for assist (under 250 W and 25 km/h).
By skipping PAS, we keep complexity and cost lower while giving the rider maximum direct control through the throttle. If you want exercise, you can still pedal like on a normal bike, but motor output is controlled entirely by throttle, similar to a motorcycle or moped.
For future kits designed for legal road use (250 W, 25 km/h), we plan to offer PAS as an option so those kits can be used as legal pedal-assist e-bikes.