Electric bicycles are increasingly popular in Europe, but their rise has brought safety concerns, particularly when users modify batteries, motors, controllers, or install aftermarket conversion kits. These modifications often allow bikes to travel at speeds far exceeding legal limits, posing risks to riders and others.

In the United Kingdom, legal electric bicycles fall under the Electrically Assisted Pedal Cycle (EAPC) category. These bikes must feature pedals, a motor with a continuous power output of no more than 250 W, and an electric assist system that cuts off when the bike reaches 25 km/h. Individuals aged 14 and over can operate an EAPC without requiring a driving license, vehicle registration, road tax, or insurance. If an electric bike's motor allows it to exceed 25 km/h, has a continuous power output above 250 W, or if the bike lacks pedals, it ceases to be classified as an EAPC. Instead, it is reclassified as a moped or motorcycle, requiring compliance with corresponding regulations for registration, road tax, insurance, a driving license, and helmet use.

Consequently, some individuals attempt to "tune" their e-bikes by bypassing speed restrictions, boosting power output, or altering controllers. These modifications enable the bikes to travel faster than 25 km/h while retaining the appearance of a standard electric bicycle. Users often modify motors, controllers, batteries, or remove speed restrictions via software, all without significantly altering the bike's external appearance.

British police inspect an electric bicycle on specialized equipment. *Telegraph*

To combat modified e-bikes, police in several European countries, including the United Kingdom and the Netherlands, have deployed "rolling road" devices. These mobile test benches feature rollers positioned beneath the wheels. Once a bike is mounted, its wheels spin, allowing the system to measure speed and motor power output, thereby determining if the vehicle surpasses legal specifications.

Authorities currently employ speed test benches from Dynostar and Wenger. Bikes are secured on the bench, and officers pedal to determine the speed at which electric assistance ceases. If the motor continues to assist beyond the legal limit, the vehicle is classified as an illegally modified electric bike. This method allows police to assess operational performance directly, bypassing the need to dismantle vehicles to identify replaced components. Each test takes approximately one minute, with riders typically processed within 15 minutes, enabling police to efficiently inspect numerous vehicles.

Dutch police utilize a mobile test bench to detect modified electric bikes. *AT5*

Once an e-bike is identified as illegally modified and fails to meet motor vehicle requirements, police can confiscate it. In Birmingham, United Kingdom, unlawfully upgraded electric bicycles are seized and subsequently destroyed. During an operation in April, 13 bikes were confiscated in a single day, including one modified to reach nearly 80 km/h. During an inspection in London in July, some e-bikes were found capable of speeds exceeding 27 mph, or 43 km/h. Riders also face penalties for offenses such as operating without a driving license or insurance, as their vehicle is then classified as a motor vehicle.

Hai Dang