PONT ST. ESPRIT, France — While few people question mandatory helmets in professional cycling and sunglasses are unlikely to disappear any time soon, the combination has an unfortunate side effect. From a distance, most of the riders at the Tour de France have become as indistinguishable as the storm troopers commanded by Darth Vader.

“It’s not easy to identify riders now that they’re all wearing helmets,” said Sean Yates, a British cyclist who rode for the long-defunct American Motorola team and who is now a team director with Tinkoff. “On the bike, they all look pretty much the same. So maybe that takes a little bit of the romanticism out of the cycling, but that’s how it is.”

Like many professional sports, cycling is an occupation best avoided by people whose preferred form of self-expression is fashion. To begin with, cycling’s rule book imposes a number of limits. Jerseys, for example, cannot be sleeveless, to at least give riders’ skin at the shoulder a fighting chance during crashes.

Image Alex Howes is not a fan of the green and red argyle socks, but they offer aerodynamic benefits. Credit... Christophe Ena/Associated Press

In the past, the rules went even further. Shorts had to be black, socks could be only white. But without helmets and, for the most part, glasses, riders were easily distinguished because the public could see their faces.