Zazzle Shop

Screen printing

Thursday, September 23, 2010

Designers Create a "More Efficient" Chainless Bike

by Stephen Messenger, Porto Alegre, Brazil
stringbike photo  
Photo via StringBike

The Bike, Unchained

A group of designers in Hungary have done away with what has long been a staple of bicycle design, those oily old chains, with their creation, the StringBike. Instead of being propelled forward the traditional way, this novel new bike utilizes a clever symmetrical rope and pulley system that may make cycling safer, smoother, and more efficient -- and it just may be the way everyone pedals around in the future.

stringbike photo

While the StringBike's system of strings is a bit more complicated than the chain and gears you're used to, the way it operates is actually surprisingly simple.

PhysOrg explains how it works:

The rotation of the pedals forces arms at each side to swing forward and backward on its shaft. When moving forward, the arm pulls the driving wire that is wound around a drum on the rear wheel, forcing the wheel to rotate. The arms at each side alternate so that when one is moving forward the other is moving backward.

The new system has 19 "gear" positions and the transmission ratio can be changed at any time by turning a shifting knob on the right handle grip. This moves the pulley shafts up and down along a traction path on an eccentric disc, which has 19 notches to adjust the height of the pulleys and distance between the center of rotation and the shaft. The gears can be changed even if the bicycle is stationary, but gear change speed increases with the speed of the bicycle.

Here's a video to give you a better idea.

Doing away with those clunky old chains in exchange for the StringBike's polyethylene rope comes with plenty of advantages for the cycling enthusiast. Because the drive system is symmetrical, utilizing both legs separately, the StringBike is said to be more efficient and easier to handle on winding streets.

And there are several other advantages of the string system that bike commuters, in particularly, are sure to appreciate. The unique design allows for quick removal of the rear tire to make the bike easier to store or carry around. Also, the strings are dry -- meaning no more arriving to work with oil-stained pant legs.

Only time will tell if this wildly innovative new string-based system can catch on in the world of bicycle design, but still one thing is for certain -- imagination, and perhaps bikes too, are best left unchained.


lj September 29, 2010 at 8:28 PM  

The Original Stringbike: