Asus has detailed the Oxiis E250G1, a friction-drive electric assistance kit designed to convert a range of conventional bicycles without modifying their gears or brakes. The system presses a powered drive wheel against the bicycle tire and uses adaptive boost technology to detect inclines and supply assistance.
The motor is rated at 250 watts with a stated peak of 500 watts. Asus lists a maximum speed of 32 km/h, limited to 25 km/h in some regions, and an estimated range from about 10 km in Sport mode to 50 km in Eco mode. Actual distance varies with rider effort, terrain and the selected assistance setting.
A 158.4 Wh, 36 V removable battery supports 100W USB-C Power Delivery charging. Asus says a full charge takes approximately two hours with the required charger. The full booster, including battery, weighs 3.7 kg and measures 400 by 84 by 128 mm. Its enclosure carries an IPX4 water-resistance rating, suitable for splashes and light rain but not heavy rain or immersion.
Riders can choose Eco, Normal and Sport modes through a button on the unit or an Android and iOS application. Eco is intended for efficient support on flatter ground, Normal balances assistance for routine riding, and Sport provides stronger boost for climbing. A wireless cadence sensor avoids a wired connection, while a brake-detecting taillight is intended to improve visibility.
The mounting design fits tire widths up to 60 mm, wheels from 16 to 29 inches plus 700C, and seat posts from 25.4 to 34.9 mm with included spacers. Asus lists city, road, gravel, folding, hybrid and hardtail mountain bicycles as compatible categories. Full-suspension frames, carbon-fiber seat posts and knobby tires are excluded or discouraged.
An anti-slip mechanism adjusts pressure on the tire, and the aluminum structure is designed to shed heat. Asus says installation requires no complex tools, but it instructs buyers to check tire, wheel and seat-post dimensions and ensure the frame and braking system are in safe condition.
Availability and specifications may differ by market. Riders are also responsible for local traffic rules, power restrictions and speed limits. The Oxiis therefore offers a removable route to electric assistance, but compatibility and legality depend on the particular bicycle and region rather than the product's broad universal-design claim alone.
The battery is described as flight-safe for carry-on luggage only with airline approval, another reason to verify rules before travel. Users should not alter power or speed limits with unauthorized software or hardware, which Asus says would void the warranty and could make the converted bicycle non-compliant.
