The device uses a friction drive system, in which a compact motor unit presses against the rear tire to spin it faster when you need extra power. An anti slip mechanism keeps that roller gripping the tire consistently, even on bumpy terrain, so power transfer stays smooth instead of slipping out under load. Asus calls this its Adaptive Boost Technology, which senses inclines and automatically adds power on hills or against headwinds without you having to switch modes manually. Riders can still...
