THE SOFA BIKE IS IDEAL FOR THOSE WHO ARE PRONE TO RIDE IN THAT POSITION

The Count de Sivrac was an ingenious fellow. In 1791 he invented perhaps one of the first functioning bicycles, a crude, pedal-less monstrosity on which he would tool around the palace by pushing his feet against the ground. Since his contraption had no steering mechanism or brakes, he almost surely invented the bicycle crash as well.

Bicycle science has progressed slowly since 1791. Foot pedals, pneumatic tires, hand brakes and derailleur gears are all significant advances, but very few people successfully tampered with the count's basic concept—that is, until Craig Mitchell, a 27-year-old metallurgical engineer from Fairfax, Calif. came along.

Mitchell recently unveiled something called the sofa cycle, a radical alternative to conventional bike design. The idea is to have a rider lie back in something resembling a stationary hammock, with his head against a foam-rubber support and his feet thrust forward to the pedals. It's roughly the position one assumes when propped up in bed watching Upstairs, Downstairs. Mitchell reasons that the supine position is more comfortable than the standard straddle, and by drastically cutting down wind resistance it theoretically increases speed. Moreover, using the seat as a brace, a rider can exert two or three times the normal pushing power.

Mitchell is not the first to tinker with the idea of a recumbent rider. The forerunner of the sofa cycle probably appeared in France about 1933. Since then, other inventors have lain down on the job—one even had the rider lying on his stomach in a breaststroke position. But because of the jumbo size needed to accommodate a reclining body, those bikes invariably handled like Mack trucks and cornered like a Winnebago in a gale. So Mitchell came up with a model that had an adjustable telescopic frame. However, he made the mistake of lending it to a friend. "The first time he tried to ride it he fell off and broke his wrist," Mitchell says. "In terms of product liability, it was not what I wanted."

After three years and five different designs, Mitchell thinks he has solved the size problem. The current sofa cycle has a conventional 40-inch wheel base and is 6' from stem to stern. While not as svelte as a racer, it still weighs a manageable 30 pounds. The master stroke was to attach the crank arms to an adjustable metal shaft which sits above the front wheel and extends about a foot beyond it. This adds length to the cycle without lengthening the wheel base and gives the sofa cycle an uncanny resemblance to a mechanical praying mantis.

Riding a sofa cycle is not simple. For one thing, there is the matter of getting on the bike. Sitting down is no problem, nor is leaning back to the headrest, or grabbing the handlebars, which extend just over one's midriff like the controls on a glider. Even picking up one foot, pushing it forward and locking it into the pedal strap is simple. It's the other foot that causes all the fuss. Your mind tells you to put it on the other pedal and start pumping like mad. Forward motion will overcome inertia every time. But your foot has other ideas. It likes terra firma. It's looking out for your well-being and thus gives rise to an impasse. There is only one way out—a friend. Get some big brawny chap to grab hold of the bike while the other foot timidly agrees to climb aboard.

While your friend runs alongside (still holding on to the bike), you get to practice balance. It feels strange. Your friend is beginning to get red in the face. "Pedal," he yells. "Don't let go." you scream. It's too late. There you are, alone, wobbling down the road with all the grace of a drunk on stilts. Your head is bouncing like a volleyball. From sheer instinct, or panic, you begin to pedal and, by gosh, the thing straightens itself out. Pretty soon you're able to balance. The legs and arms, so essential on conventional bikes, are secondary on the sofa cycle. Balance comes from the hips and back and the subtle shifting of one's weight in the hammock. It takes up to a full day, at least, for the average rider to learn this.

Next comes steering. Like a motorcycle, the sofa cycle is designed to be steered more by leaning than by turning the handlebars. A rider who is used to holding on tightly will soon find himself capsized in someone's tulip garden. Usually, two fingers on the handlebars are sufficient. That goes double for turning. The rider who swings wildly into a turn will shortly be eating concrete.

But the rider who grasps the special sofa-cycle technique is in for a treat. The bike is so aerodynamically clean that it makes a conventional model feel like a tub. Equipped with 15 speeds (the greater leverage, which comes from the braced back, allows for a higher gear ratio), the sofa cycle positively zooms downhill and on the flat. (Mitchell claims he has reached a top speed of 65 mph.) And because of its low center of gravity, the sofa cycle corners like a Ferrari.

Custom-made, the bike costs a hefty $1,000, although the price could drop to around $300 if Mitchell can get it mass-produced. But, like the Count de Sivrac before him, Mitchell is doubtless ahead of his time. While he looks for a manufacturer, he has temporarily closed up shop and taken a job at an electronics firm. "I got tired of being broke," he says.