Why do cyclists shave their legs?

Here are some of the purported reasons:

It looks sexy and lets you show off your diamond-cut calves.

It makes postride massage easier and less painful.

It makes cleaning and treating wounds easier and speeds up healing.

It's a tradition and part of the sport, so you just do it.

It makes you faster because it's more aerodynamic than hairy legs.

Depending on who you talk to — whether it's a massage therapist, a doctor, or your partner — there is an argument to justify each of those reasons.

But perhaps the most compelling reason is that shaved legs are faster, at least according to the folks at Specialized, the major California-based manufacturer of performance bicycles, which has a state-of-the-art wind tunnel.

Recently, they set out to determine whether shaved legs were in fact faster than hairy legs.

They tested a number of riders "across the entire spectrum of Chewbacca scale," eventually choosing one cyclist, Keith, who had level-6 hairiness — "fairly dense follicles."

They tested him with hair, and then they tested him without hair, 10 separate times.

The results? They were "shocked" at how big a performance difference they found.

Over 40 kilometers, or about 25 miles, Keith saved 82 seconds — nearly a minute and a half.

Although they found that Keith was on the high end of performance savings, even a rider on the low end could save 50 seconds. That's huge.

On average, that's about 70 seconds saved just by shaving your legs. After hundreds of hours of testing in the wind tunnel, Specialized said this was the most surprising revelation it's ever had.

In a bike race or triathlon, where races are won and lost by seconds, and sometimes hundredths of a second, that is an enormous difference.

The closest Tour de France in history was won — after three weeks of racing — by just 8 seconds by American Greg LeMond in 1989.

So, hair slows you down. "Smoother is faster," as Specialized says.

Is that why cyclists shave their legs? For many, especially amateur riders, it's probably a combination of all the reasons above. But for the pros you can be sure it's about saving time and going fast.

Will Keith keep shaving his legs? "Depends on what the girlfriend thinks," he said.

Watch the full video from Specialized below: