If you want to make the most of your tailwind on long days in the saddle, these US Entrepreneurs may just have the thing for you... it's a sail that attaches to the rear of your bike controlled by two handlebar-mounted buttons, dubbed the CycleWing and now crowdfunding on Kickstarter to bring the working prototype into full production.

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Attaching to almost any bike like a rear rack, the sail and mast are covered and packed when not in use (above) and when you want to boot up the sail you simply turn it on via the buttons on the handlebar-mounted head unit. The screen displays the angle that the sail is set at, and you can adjust it according to conditions. It can give you a boost from a wide range of wind directions, with about 35° to 45° on either side unable to generate any power (bad luck if you're riding into a full-on headwind).

The engineers who developed it say the CycleWing was made for long distance touring along country roads, as using it in crowded cities would have fairly obvious shortfalls.

The CycleWing is currently a working prototype and fully made in the USA, and if/when it goes into production the finished product could weigh less than 7kg if made from light materials such as carbon. They say it's arguably the greenest form of powered cycling, and to bring it to life CycleWing are looking for almost £60,000 worth of crowdfunded investment. A $500 pledge will get you one at an earlybird discount of up to 40%, with various other items offered for lower amounts. Head over to the CycleWing Kickstarter page here for more info.