On the Arantix Mountain Bike from newbie Delta 7 Sports, the typical solid-cylinder tubing has been replaced by an airy, see-through lattice woven from a carbon-fiber composite and bundled in Kevlar string. The resulting gossamer web may look delicate, but pound for pound this quirky construction—called IsoTruss—is stronger than steel, aluminum, and titanium. It’s even stronger than solid carbon composites, the current front-runners among ultralight bike frames.
Like other carbon-fiber frames, this one is baked: Long, thin strands of carbon atoms, organized in a hexagonal pattern and coated with epoxy resin, are put in an oven at 255 degrees Fahrenheit for four hours of curing. Unlike other carbon-fiber frames, though, the Arantix could withstand a direct shrapnel hit. The lattice structure isolates damage to a single element instead of shattering under pressure, Delta 7 says.
Despite all its empty spaces, the handmade Arantix frame costs a hefty $6,995 (a full bike is $11,995). At 2.75 pounds, it falls just short of a featherweight record among mountain bikes, but the IsoTruss easily supports the 200-pound-plus Clydesdale racers that its competitors shun. Our advice? Skip the frame: It would be cheaper (and healthier) to go on a diet.