Bike Like an Egyptian

Tiny pyramids make for the toughest mountain-bike frame yet

If a simple polygon can hold up a pharaoh's tomb for 4,500 years, it should survive some off-road riding. That's the thinking behind the 2.75-pound Arantix mountain-bike frame from Delta 7 Sports. It's 10 times as strong as a steel frame of the same weight would be--enough to survive the company's informal "run- over" test with a Ford F350 pickup.

The Arantix draws its exceptional strength-to-weight ratio from rods composed of several hundred layers of carbon fiber, wrapped tightly with Kevlar cord and woven to form a long series of little pyramids. The rods intersect to create hundreds of stress-bearing joints that add strength and isolate damage, so a crack in one part of the frame won't spread to another and wreck your ride.

Because each frame requires up to 300 hours of hand-weaving, Delta 7 will make only 200 this year, selling for $7,000 each starting in the spring. Spread over a few millennia, that's a bargain.