What Mark Cavendish and gear experts say about his chain coming off
Cavendish's chain has shot off his chainring following two sprints at this year's Tour. Why?
Sprinting great Mark Cavendish has won four stages of the 2021 Tour de France. Twice, his chain has come off right at the finish line as he abruptly stops sprinting to celebrate. What is going on?
We asked suppliers to the team, industry experts, and Cavendish himself about the phenomenon.
The basic situation is that when the spinning momentum of his cassette and rear wheel and the forward momentum of his chain are suddenly met with an abruptly stopped or briefly backpedaled chainring, the chain loses tension and comes off. The fact that he is usually in a big gear with his chain at an angle (53/11) may contribute. The fact that he sharply switches from a super-high cadence sprint to a brief backpedal sometimes may contribute. And a small bit of friction in the freehub that could prevent it from immediately stopping could contribute to the chain slack, too.

Whatever the cause or collection of causes, Cavendish isn’t worried.
“The chain thing has happened my whole career,” he said. “It’s more with how I ride the bike than the actual bike. I just stop pedaling very quickly when I cross the line. It’s just physics — the freewheel will keep turning.”
Indeed, Cavendish’s chain popped off earlier this year at the Tour of Turkey at the end of a sprint. In 2015, he lost his chain during a sprint, which caused consternation in the Quick-Step camp.
At Specialized Racing, which provides the bikes and the Roval wheels to the team, Scott Jackson didn’t have more to add. “Unfortunately I don’t have any explanations or inside line on this one… sorry!”

High-level representatives at other parts companies didn’t want to go on the record with speculation as to a cause.
In any event, Cavendish doesn’t appear to be worried, so long as he is crossing the line first.
“How I specialize in the past I’ve done a lot of testing on the bike and I ride very different than a lot of bike riders, and it causes some stuff that is a little abnormal,” he said. “It’s not something I worry about because it happens after the finish.”
I mentioned to one industry representative how I’ve seen this happen to others over the years, including a friend last weekend after a sprint. Their advice to my friend was this: “Have him clean his freehub and see if it improves.”
With the final stage into Paris, Mark Cavendish has a chance to set a new record for Tour de France stage wins. Let’s see what his chain does.
Andrew Hood contributed to this report.
