NASCAR 101: Why Do the Next Gen Cup Car’s Brakes Explode?

Neha Dwivedi | 21/11/2024
Detailed view of a brake rotor for the car of NASCAR Cup Series driver William Byron during practice for the NASCAR Championship race at Phoenix Raceway.

NASCAR’s Next Gen car boasts the best safety features, ensuring driver protection. However, the new model has also introduced complexities that were less pronounced in its predecessors.

While parity in speed and equipment levels the playing field, allowing for fair competition, it has also limited the flexibility in the choice of rotors and calipers, which can significantly affect performance.

Brake rotors have become a notable topic of discussion. Last year at the Enjoy Illinois 300 at World Wide Technology Raceway, several drivers, including Carson Hocevar, Tyler Reddick, and Noah Gragson, encountered issues with their brake rotors.

The issue persisted into the 2023 season’s climax at Phoenix, where a brake rotor failure caused Christopher Bell, one of the final four contenders, to crash hard into the wall, abruptly ending his championship hopes.

This year again, at the Great American Getaway 400 at Pocono Raceway, one more driver, Todd Gilliland, experienced a brake rotor failure that sent him crashing into the wall. With numerous such failures occurring, it’s apparent that this issue is growing more troublesome.

What is the reason behind the failures?

While some racing series opt for carbon-fiber brake rotors for their performance, NASCAR continues to use cast iron for its durability and cost-effectiveness. Although cast iron is robust, it struggles with thermal shock.

The rapid expansion and contraction at race tracks cause the brake rotors to deform unevenly, with different sections of the material expanding or contracting at varied rates. The uneven thermal expansion puts the material under stress, leading to strain accumulation. Over time, this strain can cause the rotors to crack.

At short tracks, brake rotors consistently run hot, while at superspeedways, they are primarily used during pit stops. There have also been alarming incidents where the brake rotor shattered and ejected from the wheel.

Interestingly, road courses, even those with long straightaways leading into tight hairpin turns like COTA, have not experienced these issues. Similarly, Martinsville, a track infamous for its heavy brake use, has seen no such failures.

The frequent breakdowns of rotors supplied by AP Racing have sparked concern.

Although the occurrences of brake rotor failures have decreased this season compared to last, NASCAR still faces a pressing need to address the issue. Brake rotor failures pose a significant risk and can lead to some of the most perilous accidents in the sport.

Post Edited By: Srijan Mandal

About the author

Neha Dwivedi

Neha Dwivedi is an experienced NASCAR Journalist at The SportsRush, having penned over 5500 articles on the sport to date. She was a seasoned writer long before she got into the world of NASCAR. Although she loves to see Martin Truex Jr. and Kyle Busch win the races, she equally supports the emerging talents in the CARS Late Model and ARCA Menards Series.. For her work in NASCAR she has earned accolades from journalists like Susan Wade of The Athletic, as well as NASCAR drivers including Thad Moffit and Corey Lajoie. Her favorite moment from NASCAR was witnessing Kyle Busch and Martin Truex Jr. win the championship trophies. Outside the racetrack world, Neha immerses herself in the literary world, exploring both fiction and non-fiction.

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