Asus Oxiis clips a 500W friction-drive motor onto any conventional bike

Asus is stepping outside its PC-and-router comfort zone with the Oxiis E250G1, a friction-drive motor that converts an ordinary bicycle into an e-bike without swapping out gears or brakes. The unit presses against the tire to deliver power, rated at 250W continuous with 500W peaks, and pairs with a wireless cadence sensor, a brake-detecting taillight, and adaptive assist that ramps up on inclines. At 3.7 kg with a removable 158 Wh battery, it targets city, road, gravel, folding, and hardtail bikes running 16–29 inch (or 700C) wheels and tire widths up to 60 mm, with spacers to fit a range of seat posts.

The battery charges in about two hours over 100W USB-C Power Delivery and is pitched as carry-on-friendly for flights, subject to airline approval. Asus quotes a 50 km range in eco mode and a 32 km/h top speed, software-capped to 25 km/h in regions that require it. A companion app for Android and iOS switches between Eco, Normal, and Sport modes, and the whole assembly carries an IPX4 splash rating.

The more telling detail for a tech audience sits in the fine print. Asus explicitly forbids using unauthorized third-party software or hardware to raise the power output or lift the speed cap, warning that any such modification voids the warranty and may push the bike out of road-safety compliance. It also pushes regulatory responsibility—local traffic laws, speed limits, and right-of-way—entirely onto the rider, a familiar pattern as consumer e-mobility gear collides with a patchwork of regional rules.