Controversial IndyCar CEO Randy Bernard resigned Sunday, though whether he was forced out of the job is unclear, racing officials said. Indianapolis Motor Speedway CEO Jeff Belskus will lead the open-wheel racing association for the time being, as a permanent replacement is sought, The Indianapolis Star reported. Bernard was popular among IndyCar fans. He was known to offer his personal email freely and interact with fans, hearing feedback and engaging in discussions about the direction of the sport. In the paddock, however, Bernard wasn\'t as well-liked. Changes to the cars\' designs were unpopular with team owners who said the changes were too expensive. Drivers were put on edge when Bernard sought a different tire supplier than Firestone, a staple sponsor of the sport with a widely respected safety record, The Star said. \"The last three years have produced some exciting, and some difficult, times,\" Bernard said in a release put out by IMS. \"But we have created a foundation for IndyCar that positions it to grow over the next several years.\"