Het Nieuwsblad (opens in new tab) reports that the UCI ratified a rule at the UCI Congress at the Fairmont Hotel in Monaco that prevents team cars from giving riders an aerodynamic advantage during time trials.

This rule was in response to the emerging trend of teams chasing individual riders with bikes on the roof racks of their team cars.

In Tirreno-Adriatico, Filippo Ganna was chased by the Ineos Grenadiers machine with eight bikes. Lemco Evenpoel's Quick Step Alfa Vinyl machine was similarly loaded with bikes. Ganna won the race by 11 seconds over Evenpoel, with overall winner Tadej Pogacar (UAE Team Emirates) in third place by 18 seconds.

The UCI did not limit the number of bikes a team car could carry. Rather, it raised the distance a team car must be behind a rider from 10 meters to 15 meters.

Richard Kelso, an adjunct associate professor at the University of Adelaide who specializes in fluid dynamics, aerodynamics, and sports engineering, told Cycling News earlier this year that the larger the area of a team car stacked with bikes, the more air is forced forward and the airflow velocity around the rider is reduced The result is less aerodynamic drag, which in turn reduces the speed of airflow around the rider. The result is less drag and better performance. It's a small thing," Kelson said, "but it's enough [to make a difference].

Belgian professor Bart Brocken studied the issue and showed that Ganna benefited by as much as 3.9 seconds in the 50 km and 1 second in the Tirreno-Adriatico.

A 15-meter gap between the rider and the team car would effectively eliminate the advantage. This was officially announced today and will begin on January 1, 2023.

Regulations regarding the fit of time trial bikes have also reportedly been adjusted, with the required distance from the tip of the saddle to the end of the bar extension, arm pad drop, and saddle setback.

The UCI also discussed plans for pinless bib numbers after riders requested in June that they stop using mesh number pockets and other pinless solutions on road stages. In the time trial, athletes were still allowed to use pinless bib numbers.

By 2024, the UCI aims to have an industry standard solution for pinless numbers.