Riders at the Tour de France Femmes can expect more detailed clothing checks before stage 4’s time trial after reports that riders may be using additional padding in their bras to gain an aero advantage after the UCI issued a special warning about items “which could modify riders’ morphology”.

Wielerflits published a story on Sunday about this potential issue, noting that riders have sometimes appeared to have a larger chest size during time trials compared to road races, and reporting that several WorldTour teams have voiced their concerns over riders’ artificially changing their breast size using padding during races.

An increased volume in the chest area can have significant aerodynamic gains, as it redirects the airflow around the body, for both men and women.

Chest fairings, which are essentially items put down the front of the jersey to change the shape of the chest, have been found to be effective in saving watts and therefore time, particularly in aero positions for cyclists and triathletes, and have been banned by several governing bodies, including in cycling.

Lidl-Trek’s head of technical and innovation told The Athleticthat his team have tested different kinds of bras and found some more padded bras to have benefits, but did say that it’s not something the team have actually used in racing.

Under articles 1.3.032 and 1.3.033 of the UCI rules, riders may not use any objects to artificially change their morphology, and any kind of fairings or textured fabrics are banned.

At the 2025 World Championships in Rwanda, riders from Belgium had their radio pockets on their chest rather than their back, with no penalties, and riders have sometimes ridden with bottles down the front of their jersey, though the UCI has tried to police that.

For male riders, the policing of chest fairing use is relatively easy, but it becomes complicated for women, who all have different sized breasts and use all different kinds of sports bras during races.

Some riders have opted to race without a sports bra – that often minimises and compresses the breasts – for aero gains, but Wielerflits reports that some riders are doing the opposite, using padding in their bras to increase their breast size or alter their chest shape in a way that is difficult to police or detect.

However, since Wielerflits’ story caused a stir in the paddock, the UCI jury did something unusual on Monday evening and added an extra warning to the Tour de France Femmes communiqué ahead of the stage 4 time trial.

“Riders must be to the final checks before the race (bikes and outfit) no later than 10 minutes before their respective start time,” the communique reads, which is normal, but then it goes on to say: “Particular attention will be paid to compliance with article 1.3.032 of the UCI regulations, including nonessential elements and clothing or other items/accessories worn by a rider (including but not limited to helmets, glasses, shoes or in-race communication devices) which could modify riders’ morphology.”

It’s not often a warning like this is specifically given before a time trial.

The question, though, is how will these checks take place without being invasive? According to Wielerflits, some teams have suggested that riders could be checked in a private tent by a female jury member to ensure there is no padding or extra material in their sports bra or clothing, but even this likely feels invasive to some.

What’s more, the rule is a likely grey area, with no defined amount of padding or support a bra may or may not have, with different women having different needs and preferences.

However, with the UCI sharing the special warning on Monday, it suggests that they will be attempting to carry out extra checks on Tuesday.

Support our unrivalled coverage of the Tour de France Femmes and women’s cycling by subscribing to Cyclingnews. In return, you get unlimited access to high-quality journalism, with breaking news, race analysis, and expert insight from inside the women’s peloton. Plus, the Cyclingnews app lets you follow the action wherever you go! Join today.

Riders at the Tour de France Femmes can expect more detailed clothing checks before stage 4’s time trial after reports that riders may be using additional padding in their bras to gain an aero advantage after the UCI issued a special warning about items “which could modify riders’ morphology”.

Wielerflits published a story on Sunday about this potential issue, noting that riders have sometimes appeared to have a larger chest size during time trials compared to road races, and reporting that several WorldTour teams have voiced their concerns over riders’ artificially changing their breast size using padding during races.

An increased volume in the chest area can have significant aerodynamic gains, as it redirects the airflow around the body, for both men and women.

Chest fairings, which are essentially items put down the front of the jersey to change the shape of the chest, have been found to be effective in saving watts and therefore time, particularly in aero positions for cyclists and triathletes, and have been banned by several governing bodies, including in cycling.

Lidl-Trek’s head of technical and innovation told The Athleticthat his team have tested different kinds of bras and found some more padded bras to have benefits, but did say that it’s not something the team have actually used in racing.

Under articles 1.3.032 and 1.3.033 of the UCI rules, riders may not use any objects to artificially change their morphology, and any kind of fairings or textured fabrics are banned.

At the 2025 World Championships in Rwanda, riders from Belgium had their radio pockets on their chest rather than their back, with no penalties, and riders have sometimes ridden with bottles down the front of their jersey, though the UCI has tried to police that.

For male riders, the policing of chest fairing use is relatively easy, but it becomes complicated for women, who all have different sized breasts and use all different kinds of sports bras during races.

Some riders have opted to race without a sports bra – that often minimises and compresses the breasts – for aero gains, but Wielerflits reports that some riders are doing the opposite, using padding in their bras to increase their breast size or alter their chest shape in a way that is difficult to police or detect.

However, since Wielerflits’ story caused a stir in the paddock, the UCI jury did something unusual on Monday evening and added an extra warning to the Tour de France Femmes communiqué ahead of the stage 4 time trial.

“Riders must be to the final checks before the race (bikes and outfit) no later than 10 minutes before their respective start time,” the communique reads, which is normal, but then it goes on to say: “Particular attention will be paid to compliance with article 1.3.032 of the UCI regulations, including nonessential elements and clothing or other items/accessories worn by a rider (including but not limited to helmets, glasses, shoes or in-race communication devices) which could modify riders’ morphology.”

It’s not often a warning like this is specifically given before a time trial.

The question, though, is how will these checks take place without being invasive? According to Wielerflits, some teams have suggested that riders could be checked in a private tent by a female jury member to ensure there is no padding or extra material in their sports bra or clothing, but even this likely feels invasive to some.

What’s more, the rule is a likely grey area, with no defined amount of padding or support a bra may or may not have, with different women having different needs and preferences.

However, with the UCI sharing the special warning on Monday, it suggests that they will be attempting to carry out extra checks on Tuesday.

Support our unrivalled coverage of the Tour de France Femmes and women’s cycling by subscribing to Cyclingnews. In return, you get unlimited access to high-quality journalism, with breaking news, race analysis, and expert insight from inside the women’s peloton. Plus, the Cyclingnews app lets you follow the action wherever you go! Join today.