2 + 2 = 10?
Lance Armstrong is the current king of the Tour de France.
Like most Tour riders, he's mounted on a carbon-fiber bike. Unlike the
rest, his is a stock bike.
Courtesy Trek.
By wrapping fibers every-which-way, bike designers can make incredibly strong lugs that feel almost weightless.
If
the idea of spending a few thousand bucks on a bicycle does not make you
cringe, you've probably already considered a carbon-fiber bike. Light, fast,
stylish and titanically expensive, carbon fiber is the material of choice
for speedsters like Lance Armstrong, who has ridden a carbon-fiber
bike to victory in three consecutive Tours de France.
You could credit Armstrong's winning ways to an astonishing cardiovascular system, a major capacity for punishment, and superior bikes made by Trek Bicycle Corporation.
Carbon
fiber is so strong that some frames weigh less than three pounds, important
when you consider that bike racers, like aviators, worship at the idol
of light weight. Lugging extra kilos up a hill can spell the difference
between winning and losing.
To get an idea of how carbon-fiber composite products are designed and produced, The Why Files decided to trek over to Trek's plant in Waterloo, Wis., which also makes bikes from steel, titanium and aluminum.
Bike frames are little more than tubes connected to lugs. Trek buys carbon-fiber tubes and makes its lugs. Like most Trek employees, we didn't get to watch the lug-making. We assume their secret recipe incorporates design (orienting the layers of fiber inside the lug to take projected strains) and process (using enough heat and pressure to bond the polymer and eliminate voids).
The lugs and tubes are then joined with glue and the frame is aligned and assembled in a jig. After curing, the frame is polished and painted. Then, in another factory, the components are assembled.
Composite poses particular challenges to bike makers. While metal frames can be aligned after assembly, carbon frames are stiff. And as we've mentioned, drilling causes weakness, so components are glued, not screwed, into place.
Torture chamber
To make sure its bikes will perform, Trek systematically abuses frames in a little shop of horrors at the plant. The goal is to exert more force on the frame than a normal rider would normally do -- and then repeat the process, say, 100,000 times.
Cusack says torture testing detects when a frame is underbuilt, or, almost as critical, overbuilt. By destroying bikes of other manufacturers, Trek can keep its quality competitive. Testing also helps defend against liability lawsuits based on poor quality.
Even your ancient Schwinn could ride across the new "all-composite, no-steel" bridges. Ditto for your truck.
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