Asus has unveiled the Oxiis E250G1, a retrofit electric-assist kit that can be mounted on an existing bicycle to add electric assistance. The approach adds a motor and battery without replacing the bicycle with an e-bike.

On Aug. 17, online media outlet Gigazine reported that the Oxiis E250G1 is a product that combines a motor and removable battery into a single unit and mounts to a bicycle seatpost. It works by using a motor roller that directly contacts the tire to assist rotation.

A key feature is that it does not require major changes to an existing bicycle’s drivetrain or brakes. Asus explained it is designed to be installed without replacing gears or brakes. It also provides a wireless cadence sensor, removing the need to route a separate sensor cable along the frame.

The motor is rated at 250W with a maximum of 500W. It also includes Adaptive Boost Technology, which automatically adjusts assistance strength depending on the gradient. Riding modes are Eco, Normal and Sport, and can be changed via buttons on the unit or the Asus Oxiis app for Android and iOS.

Battery capacity is 158.4Wh. Asus said the kit can travel about 50 km in Eco mode and about 10 km in Sport mode. The battery is removable and can be charged in about 2 hours using a 100W USB Type-C PD charger. Another feature is the use of USB-C charging for the electric-assist device.

The product weighs 3.7 kg including the battery. It supports 16-inch to 29-inch wheels, the 700C standard, and tires up to 60 mm wide. It supports seatpost diameters of 25.4 mm to 34.9 mm, allowing use on city bikes, road bikes and folding bicycles.

It cannot be installed on full-suspension bicycles or carbon seatposts. Tires with large tread blocks are also not recommended. The rear includes a smart taillight that detects braking.

Top speed is listed at 32 km/h, and is limited to 25 km/h in some regions. As regulations on electric-assist bicycles differ by country, users should check local laws on actual usability. Asus also advises checking local traffic laws and speed limits where it is used.

The Oxiis E250G1 targets consumers who want to use an existing bicycle instead of buying a complete e-bike. Accessibility is higher because it adds only electric assistance without changing the bicycle, but ease of installation, riding stability and compliance with local regulations are expected to be key variables in the market.