In the local cyclocross circles, it's known simply as "the flying machine".
It's actually a Cheltenham-Pedersen, ca. 1980.
It's one manufacturer's re-pop version of an 1890's Dursley-Pedersen, touted at the time as the lightest bicycle in the world.
Ridable examples from the turn of the century came in under 20 pounds. Mine weighs about 29 lbs in CX trim, give or take a pound for the XC and RR setups.
BTW, I broke the frame in my first outing at the Napa course (ably repaired by Hugh Enox) but it has held together for another twelve years of racing.
The bike features a sprung hammock saddle, a form of suspension.