The 2026 Formula 1 regulations have once again given teams freedom to design their own wheel rims, and engineers have immediately turned that opportunity into another performance tool. Hollow spokes and specially shaped thermal pockets are being used to influence how heat moves between the brakes, rims and tyres, helping teams control both tyre temperatures and stabilised operating pressures. What makes the concept particularly interesting is that the same technology can serve very different purposes depending on the car and circuit.
Years ago, when the FIA presented the first draft of the 2026 regulations, teams feared the rules would be excessively restrictive. They therefore pushed for revisions that would provide engineers with greater design freedom, changes that were eventually approved at the end of 2024. Aerodynamically, that additional freedom has already allowed teams to explore significantly different concepts, but the wheel rims have also emerged as an important and less visible development battleground.
Why F1 wheel rims have become a development area again in 2026
Compared with the previous technical cycle, teams now enjoy considerably greater design freedom around the wheel rims. They have once again become a useful engineering tool for managing tyre temperatures and pressures, something that has already created a new tyre-cooling development battle between F1 teams.
The situation is similar to the regulatory era before Formula 1 returned to ground-effect cars. During the subsequent technical cycle, the FIA imposed a standardised solution, limiting the potential performance gains teams could extract from rim design.
Towards the end of the 13-inch wheel era, before the switch to 18-inch rims in 2022, Pirelli had even identified from team data that certain cars were able to run with lower stabilised minimum tyre pressures than the values prescribed at the beginning of a run. The way those teams managed heat through their wheel rims played an important role in making that possible.
The move to 18-inch Pirelli tyres created more physical space between the brake assembly and the wheel rim. Under the 2026 rules, however, this area has once again become fertile ground for development, with teams working alongside external suppliers including BBS, Fondmetal, OZ Racing and Enkei.
As Pirelli had anticipated before the beginning of the season, the opening races demonstrated how teams can achieve lower stabilised operating pressures by exploiting specially designed pockets within the rims. It is an apparently small detail, but one capable of influencing an extremely important part of tyre behaviour.
How brake cooling affects the wheel rims and tyres
For several years, the regulations have required all air used to cool the brakes to remain contained and exit through a clearly defined area, preventing teams from exploiting that airflow for secondary purposes. That does not, however, stop engineers from influencing the way heat is transferred between components. Some transfer is unavoidable given the extremely high temperatures generated by the Formula 1 braking system.
Brake drums have consequently incorporated increasingly sophisticated internal ducting designed to improve cooling. These layouts have become even more complex in recent seasons, with engineers using CFD to study how fresh air enters the assembly and lowers component temperatures while maximising cooling efficiency.
The importance extends beyond the brakes themselves. Heat generated in this area can transfer into the rim and, from there, into the tyre. That is why brake cooling and thermal management have become valuable performance tools, even when many of the most important solutions are largely hidden from television cameras.
Ferrari has also paid close attention to this interaction on the SF-26. Earlier in the season, the Maranello team introduced revised brake cooling solutions on its 2026 car, underlining how closely brake temperatures and tyre management are connected in modern Formula 1.
Hollow spokes and thermal pockets work like heat exchangers
“Freedom with the wheel rims is an opportunity for the teams. It may not be very visible on television to the general public, but it is significant,” explained Dario Marrafuschi, Pirelli’s Head of Motorsport, in an exclusive interview with Motorsport.com. “The wheel rim design has changed a lot compared with last year. We have seen rims with hollow spokes, which some teams call pockets, and this is precisely to promote heat exchange with the cooling of the brake drum.”
Fresh air circulating around the outer section of the brake drum, together with external airflow reaching the outside of the wheel covers, can be guided towards the areas containing these pockets. The objective is to help cool the rim itself, which is directly connected to the tyre.
Rather than simply reducing the temperature of the rim surface, the broader objective is to control the temperature at the core of the tyre. The rim therefore becomes another element within the overall thermal-management system rather than simply a structural component connecting the tyre to the car.
The size of these thermal pockets can also change according to requirements, with differences between the front and rear wheels depending on what each team needs from its car. In practice, the pockets behave like small heat exchangers.
Crucially, however, wheel-rim development is not aimed at achieving one universal objective. At particularly hot circuits or tracks featuring heavy braking demands, teams may want to keep tyre pressures and temperatures as low as possible. A larger contact patch also helps distribute heat across a broader area rather than allowing it to become concentrated.
Why teams want to keep tyre temperatures and pressures under control
As tyre temperature rises, internal pressure also tends to increase. That reduces the size of the tyre’s contact patch with the asphalt. When both temperature and pressure become too high, there is an increased risk of moving the tyre outside its optimum operating window.
Once overheating begins, grip falls and thermal degradation increases. At races where this becomes a major concern, the priority is therefore to keep the tyre as cool as possible. Spain provided one example of how significant this challenge can become when high temperatures place sustained thermal stress on the tyres. Ferrari also gained additional Pirelli testing mileage around the Barcelona event, where tyre management was an especially important factor.
Cadillac offers another useful example. The team is among those that suffer more heavily from overheating-related degradation, partly because it has struggled to keep brake temperatures under control. Alongside work on the fresh-air ducting, Cadillac introduced a new wheel-rim specification at Spa specifically designed to improve heat management and reduce degradation.
“Among the various teams, we can see who is able — I wouldn’t say to manage it better, but to manage it differently — because one team might have the objective of heating the tyre while another wants to cool it, depending on the balance of the car,” Dario Marrafuschi explained. “So we see differences, and it is a significant performance lever.”
F1 wheel rims can also improve tyre warm-up
The most intriguing aspect of the technology is that cooling the tyre is only half of the equation. Wheel rims can also be configured to help generate tyre temperature when warm-up is difficult.
“It is effectively possible to control the increase in pressure, from the starting pressure through to the stabilised pressure, and sometimes when we see a certain consistency in lap times over a long run from a performance perspective, that is also determined by how well the team manages the pressures, keeping them within the optimum window throughout the long run with the help of these devices,” Dario Marrafuschi explained.
This is where the different philosophies become particularly interesting. Not every team is pursuing the same objective, and priorities can change from one circuit to another.
At tracks with high thermal stress, the focus might be on cooling the rear tyres to limit overheating. At low-energy circuits, however, where bringing the tyres up to temperature is more difficult, engineers may instead want to radiate additional heat towards the tyres. The objective in that situation is to reach the optimum operating window more quickly, increasing grip while reducing the risk of graining.
This balance has already emerged as an important theme during the 2026 season. Differences in how individual cars generate and retain tyre temperature can dramatically alter performance depending on conditions, as illustrated by the contrasting tyre warm-up behaviour seen between Ferrari and Mercedes.
It also explains why simply designing the most aggressive cooling solution does not guarantee an advantage at every Grand Prix. A concept that is highly effective during a hot race could become a disadvantage in colder conditions if the car then struggles to generate sufficient tyre temperature.
Teams can develop different wheel rims during the F1 season
Teams are permitted to change wheel-rim specifications during the season and introduce further developments. Pirelli mounts each tyre using a unique code that is checked by the FIA on a race-by-race basis, meaning the rims themselves remain an area in which constructors can continue investing.
The fact that teams are committing resources to this development demonstrates that they believe there is a genuine performance return. Like other technical developments, however, spending on new rim specifications falls under Formula 1’s budget cap, so teams need to plan carefully how often they introduce new solutions and whether the potential gain justifies the cost.
“In general, running at lower pressures is an advantage for grip, but depending on race pace and the performance of the car, some teams have the problem of keeping pressures down because when they are going very quickly they generate a lot of tyre temperature, while other teams might have the opposite problem,” Dario Marrafuschi explained.
“Not everyone is doing the same thing. But they are an engineering tool for getting the car to make the tyres operate in their optimum condition.”
That final point captures why something as apparently simple as a wheel rim has become such a valuable development area under the 2026 regulations. Hollow spokes and thermal pockets can help control the evolution of pressure during a stint, limit overheating and thermal degradation, or work in the opposite direction by transferring additional heat towards a tyre that is struggling to reach its ideal window.
The gains may be largely invisible from the outside, but they can influence consistency across an entire race stint. As teams continue refining their understanding of the new generation of cars and tyres, wheel-rim design has become another example of how Formula 1 engineers can turn an apparently minor component into a meaningful performance tool.
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