LOUISVILLE, KY. While air disc brakes are practically standard on commercial trucks in Europe, they remain a premium option here in North America. According to Kishor Pendse, president of Bendix Spicer Foundation Brake LLC, this is not likely to change anytime soon.
“It’s going to be a long-term effort for trucking to switch to air disc brakes in North America--up to a 15-year transition period,” Pendse said at the Mid-America Trucking Show. “Regulations governing the stopping distance requirements for commercial trucks won’t by themselves drive that transition; economic and safety factors will drive that shift.”
As head of a joint venture formed between Bendix and Dana Corp.’s Spicer division last year, Pendse said that for the most part the cost of air disc brakes vs traditional drum brakes puts them on the premium rather than standard side of the specs ledger. He points out, however, that the price differential is application-sensitive.
“Air disc brakes are very application sensitive,” Pendse explained. “A fleet operating in mountainous regions, for example, is going to find air disc brakes a much more valuable selection because they don’t suffer from ‘brake fade’ the way drum brakes do after repeated use.”
Pendse noted that drum brake technology is improving to the point where drum brakes could comply with the new stopping distance requirements being considered by NHTSA without major changes to the design.
“One of the solutions is increasing the drum size from 15 to 16.5 inches to handle higher torque output on the steer axle,” he said. “We already offer that as an option. But that adds cost to the drum brake system and may require axles to be larger. It does not change how drum brakes behave, meaning their stopping power is reduced as they get hotter.”
That’s going to be one of the many factors outside of regulatory initiatives that could pull fleets to air disc brakes over the next decade, Pendse noted.
“The main issues are going to be economic, brake performance, safety and driver preference,” he said. “These are more intangible than a strict price comparison between the two. There’s going to be a balance between drum and air disc brake use going forward, which is why we will continue to invest in our drum brake products for the future.”
