Every heavy truck and trailer uses drum brakes.
If drum brakes were that terrible, I doubt that the heaviest vehicles on the road would use them.
What you need to know about air disc brakes as they increase in popularity
Over the past few years, the take rate of air disc brakes (ADBs) has been steadily growing. This growth has only accelerated recently, thanks in part to the fact that many truck OEMs have made air disc brakes standard equipment. International, Kenworth and Peterbilt are among the manufacturers who now offer ADBs as standard on their Class 8 models, and Freightliner Trucks
recently announced that they will offer ADBs as standard on the new Cascadia beginning this spring.
From an equipment spec’ing perspective, the difference between disc brakes and drum brakes is simple: Drum brakes cost less up front, but disc brakes provide better performance, including improved stopping distance, and a decreased need for maintenance. It seems that an increasing number of fleets are calculating that the trade-off is worth it, and OEMs are starting to do the same.
ADB take rates are lower for trailers than for tractors, which has been true from the beginning. The brake manufacturers estimated that the number of trailers spec’d with ADBs is currently in the 12 to 15% range. However, the increased number of disc brakes on tractors is spurring more growth in the trailer market as well, especially from fleets spec’ing new trucks with ADBs as standard.
“Disc brake penetration was higher on tractors even before some of these OEMs made disc brakes the standard offering,” says Jeff Wittlinger, business unit director of wheel-end and braking systems for Hendrickson. “As a result [of OEMs making ADBs standard], we are seeing more fleets experiment with disc on trailers.”
“We are seeing more orders for disc brake trailers from fleets looking for a common platform across their fleet,” agrees Greg Cooper, product manager for disc brake systems with Stemco. “In fact, we expect about half of the trailer market to convert over the next 10 years.”
Frankiewicz says that in Haldex’s view, the trailer segment will shift priorities to ADB very quickly, hitting 50% market share sometime around 2022-2023.
International Trucks is one of the OEMs offering air disc brakes as standard—in this case on the Class 8 LT Series.
Jim Nachtman, International’s heavy-duty product marketing director, says that the OEM “recognizes the clear advantages of ADB,” calling out the shorter stopping distance, reduced CSA violations and longer life of the brake pads as reasons International put ADBs in the standard position on the LT Series.
Nachtman says that the reaction from fleets to having ADBs as standard equipment has been positive.
“With safety and cost of ownership of paramount importance, fleets are recognizing the benefits of air disc brakes,” he says. “We are seeing air disc brakes rapidly growing in popularity in the regional haul RH Series as well. Overall, we anticipate that the popularity of air disc brakes will continue to increase.”