Through an accelerated testing process dubbed the “ICON1K” R&D program, ICON has spent over a year pushing the Tundra to off-road extremes to identify limiting factors in OE components and further extrapolate performance out of this vehicle. In a push to provide unparalleled ride quality and vehicle dynamics for everything from high-speed desert running to off the grid expedition, the RXT Rear Suspension System was born. The RXT Rear Suspension System is a combination of an all-new ICON multi-rate leaf spring, a hydraulic rear bump stop kit, and three RXT-specific 2.5 Aluminum Series rear shock options. Installation of this system replaces the aforementioned “limiting factors” and completely redefines the potential of the 2007-2021 Toyota Tundra with a 20% increase in wheel travel and the ability to adjust the leaf spring rate to compensate for varying vehicle setups.