Tensegrity is a word coined by Buckminster Fuller to describe structures where strength and integrity are achieved by balancing members under compression, with other that are in tension. In creating a bike frame where most of the members are under tension, Romanian designer Ionut Predescu's Wire Bike replaces most of the tubing with high strength carbon fiber and Kevlar cables, saving lots of weight in the process.

I used to build racing bikes, and while I don't doubt the Wire Bike's basic strength, I wonder whether it will have sufficient lateral strength to avoid flexing when a rider really stands on the pedals.

Yanko Design, via Treehugger.com