November 23, 2009
The Dutchess, from magnificently-named designer Wytze van Mansum, is the best concept bike we have seen in a long time. It is both practical, innovative and, even better, exists in the real world as a proper working machine.
Designed for Cannondale, the Dutchess is a woman’s bike based on the heavy old Dutch bikes popular in Europe (hence the punnish, creatively misspelled name). At fist glance you actually see nothing more than a streamlined, duck-egg blue version of the these omafiets (granny-bikes). But take another glance at the hubs, bottom-bracket, handlebars and even the rear fender and it starts to reveal itself as a rather futuristic machine.
First, the frame itself. The whole bike weighs in at just 14 Kg (31 pounds) and is based around the swooping bar that runs from the handlebar all the way to the back. On top of that is the tubular fender, which is structural and can support up to 50 Kg, or 110 pounds. Inside these hollow tubes are contained the brake lines (they are hydraulic) and cabling for the lights (they’re built-in and powered by the hubs).
Speaking of the hubs, these are innovative in themselves. The rims are laced to a generic hub into which can be slotted various cassettes. This means that both front and back wheels are identical, only the rear has the drive system and brake, and the front a generator and a brake. This would make repairs easier as you don’t have to rebuild the whole wheel just to change hubs. Wytze is realistic, though. Speaking to the excellent Bicycle Design blog, he says that “This is dreaming: [the hub] is a better standard then the current solution, but it will never happen.”
Another thing that may never happen is the crank, which as you can see does not use a chain. The actual drive train has not been revealed by Wytze, although it may have something in common with another design he came up with for a folding bike, which uses a cord and a cone-shaped freewheel to transfer power. In the accompanying video (below) it seems to work fine, and Wytze told Bicycle Design that the efficiency is a resectable 96%, compared to a chain’s 98%.
Up at the front, those handlebars can be left where they are or, with the flick of a locking lever, swept forwards or backwards for a more sporty or more comfortable position. A side-effect is that if the bars are pushed right back, the ends touch. As they can be locked in place, this forms a low-security lock that could be looped around a post.
When the handlebars are locked like this, the brakes are also secured (pressure is kept on the hydraulic fluid) for added security.
There is more. The gap between the rear fender and what would be the chain-stay on any other bike is covered with a skirt (or overcoat) guard, and everything is designed to be maintenance-free: the original sketches even put airless tires on there for puncture-free riding. The rear fender has a pull-out extension for really rainy days and the design (but not the prototype, which took five months to build) has a front basket and a kick-stand.
This is a very nice update to the Dutch bike. Even without all the smart extra features the weight advantage alone is worth it (and means you can carry it upstairs to your apartment to sleep). For more, check out the interview with Wytze over at Bicycle Design, and view some more (hot) product shots at his Flickr page.
Source & video
