Actually, one of the biggest complaints with Cannondale's forks is their limited travel. This is because it's a single device mounted as part of the headset. So, in order for Cannondale to keep up with the move towards longer suspension travel, the took a dual crown fork (which allows for more travel) and realized they could get the weight close to a single crown fork by cutting the dual crown in half.

This was attempted in BMX a bunch of years ago, but w/o suspension and the technology wasn't available to make them work. The design isn't really a "fork" it's actually a "STRUT", you know like what a lot of aircraft use for their landing gear. Cannondale figured if this design was good enough for landing gear and all the imposed loads and stress in that application, they could sure as heck make bike suspension work.

They did!

I like the Lefty and NEVER had a problem with mine. Looked cool and different too.

The only problem was buying replacement parts. It's obviously all proprietary.

L8R