Bosch eBike ABS Braking | How it Works

One of the big new advancements in ebike technology of late is the introduction of ABS braking for electric bikes. Bosch have leveraged the technology from their Motorsport division and partnered with brake manufacturers such as Magura to develop Bosch EBike ABS Braking. Here is a brief explanation on how it works.

ABS stands for Anti-lock Braking System. It's a safety feature in vehicles designed to prevent wheels from locking up during braking, thereby maintaining tractive contact with the road surface. When you apply brakes suddenly or forcefully, especially in emergency situations, there's a risk that the wheels could lock up, leading to loss of steering control and increased stopping distance.

Here's how ABS works:

1. Wheel Speed Sensors: ABS-equipped vehicles have sensors on each wheel or sometimes on the differential that monitor the speed of rotation. If one wheel is significantly slower than the others, it suggests that it's about to lock up.

2. Control Module: The information from these sensors is sent to a central control module, which constantly monitors the wheel speeds.

3. Pulse Modulator: When the control module detects that a wheel is about to lock up, it sends a signal to a hydraulic modulator, which modulates the brake pressure to that wheel. This is typically done by rapidly releasing and reapplying the brake pressure, creating a pulsating effect.

4. Pulsating Brakes: As a result, the brakes pulsate rapidly, effectively preventing the wheel from locking up. This allows the driver to maintain steering control and reduce stopping distance, even under heavy braking.

5. Release and Reapply: The ABS system continuously adjusts the brake pressure to each wheel, releasing and reapplying as needed, until the vehicle comes to a stop or the driver releases the brake pedal.

By preventing wheel lock-up, ABS helps the driver maintain control over the vehicle during emergency braking situations, reducing the risk of skidding and loss of control. It's a significant safety feature that has become standard in most modern vehicles and is now available for certain ebikes. 

Here are some pics of the different ABS components on a Riese & Muller Load4 75 Rohloff cargo ebike (designed to carry three children).