Lucas Bell 
Over the last couple of years, there has been a huge increase in popularity when it comes to classic 4×4 off-roaders. The market for these well styled and highly customizable SUVs has exploded, with early examples of models like the Ford Bronco or Toyota FJ Cruiser commanding hefty price tags regardless of condition. While these trucks are certainly some of the best looking to ever hit the dirt, they aren’t particularly good to drive. This is where Roadster Shop comes into play, and its new RS4 chassis that debuted at the 2019 SEMA Show.
Roadster Shop has been watching the growing aftermarket for these old school off-roaders, particularly when it comes to the Ford Bronco. As owners begin to modify these trucks, they quickly realize that the 50-year-old SUVs need quite a lot of help to meet modern performance standards. The Mundelein, Illinois-based shop recognized the need for an aftermarket chassis to help make these trucks as capable as they look, which culminated in the RS4 chassis, specifically for the 1966-77 Bronco.
While only the RS4 Bronco chassis was on display, Roadster Shop plans on offering similar setups for 1965-1971 Dodge pickup trucks, 1962-1991 Jeep Wagoneer, and 1947-1954 Chevrolet trucks.
The complete chassis begins with Roadster Shop’s beefy 5-inch x 2.5-inch .188 wall frame rails, which adds a significant amount of strength compared to the standard chassis, which can be critiqued as undersized. The design of the rails help Roadster Shop’s chassis to gain 3.5-inches of width in between the rails, allowing for simpler header installation and steering routing. While this packaging makes a Coyote engine swap ideal for the chassis, all of the most popular classic and modern engine and transmission combinations have standard mounting provisions available from Roadster Shop.
In fact, Roadster Shop has gone all in on maximizing the hardware mounting parts across the platform. All of the original body mounting locations have been engineered into the RS4 Bronco chassis, which allows for bolt on installation without the need to cut into the original body panels at all. The ride height has also been optimized to eliminate the need for a body lift.
The aftermarket chassis isn’t just made up of an improved frame, but also includes some of the best off-roading parts in the industry. For example, Currie Dana 44 front and Dana 60 rear differentials are tied into the chassis via a triangulated 4 link system that is optimized for anti-dive, anti-squat, and maximum suspension articulation. An Atlas 2-speed transfer case handles the 4×4 duty, while Fox Racing 2.5 Factory Race Series coilovers with RS4 specific valving provide the necessary off-road performance and on-road ride quality.
The base Roadster Shop RS4 Bronco chassis starts at $36,495 before options, while the more hardcore RS4R Bronco SUV chassis is currently listed for a base price of $64,995. The RS4R 12-inches of front travel and 13-inches rear travel, fully independent front suspension, and mounting kits specific to the Coyote and LS V8 crate engines.
Maybe Jay Leno would like one of these for his 2020 Mustang Shelby GT500-powered Ford Bronco.
