If you want to own "the world's lightest folding bike" right now, you're likely to end up choosing between the Allen Sports Ultra X (8.5 kg/18.75 lb) or the Bike Friday Pocket Rocket Super Pro (7.5 kg/16.5 lb, depending on how it's set up). If a new Kickstarter campaign is successful, however, that will soon change. The carbon fiber Hummingbird is claimed to weigh just 6.5 kg (14 lb).

Designed and built in the UK, the Hummingbird will be available in both singlespeed and 5-speed models. Both of those will in turn be available with either 16-inch or 20-inch wheels. The latter version won't be quite as light as the former, tipping the scales at an estimated 7 kg (15 lb).

The Hummingbird folds up within seconds, utilizing a mechanism in which the aluminum alloy rear swingarm pivots down to sit beneath the top tube. Because the Litepro crank stays in one place throughout the process, the chain doesn't loose tension and therefore doesn't fall off – something which can happen with some other folding designs.

Other components include a carbon fiber main frame, fork and handlebars, along with Litepro wheels and Schwalbe Kojak tires. The 5-speed will utilize a Sturmey-Archer or SRAM internal hub and grip shifter

If you're liking the sounds of the Hummingbird, a pledge of £1,100 (about US$1,674) will currently get you a singlespeed, with £1,250 ($1,902) required for the 5-speed – assuming all goes according to plans. Their estimated retail prices are £1,750 and £1,890 ($2,663 and $2,876), respectively.

By contrast, the 20-speed Allen Sports Ultra X will set you back $4,999. And should you really want what is absolutely the lightest folding bike in the world, well, that would probably be the 5.4-kg (12-lb) A-Bike. The only thing about it is … well, just take a look at it.

The Hummingbird can be seen in use, in the video below.

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