Fancy working up a sweat to charge your phone with green energy?
Wheelswing, a contactless dynamo from South Korean company With Us could be just the thing. Retailing for $135 (£105, AU$180) for the version with a built-in 1,000mAh battery, the dynamo sits near the bicycle rim, but not touching it, and generates a current when you pedal at 10 kph (6 mph) or more.
The dynamo spins due to the electromagnetic current generated when your wheel is turning, via eddy current from the wheel rims. That's apparently enough to charge your phone, as the dynamo generates around 500 to 700mAh per hour, according to With Us President Hur Younghui, who was at his company's booth at Computex's startup area, Innovex.
If you're worried about adding too much weight to your bike, the Wheelswing is just 320g, which feels light enough to not affect your ride too much.
The Wheelswing is only available in South Korea for now, but it could be available worldwide soon. While it's not the first, it's likely one of the first few to be able to charge your mobile phone on the go.
Be sure to check out the rest of CNET's Computex 2017 coverage here.