True high performance front suspension is finally available for the 2008 and later Harley-Davidson Fat Bob models (FXDF). Progressive Suspension has gone back to the drawing board and created a state of the art Fork Cartridge Kit "designed to outperform everything on the market." Progressive Suspension's new asymmetrical design places a preload adjuster over a progressive rate spring in one leg and an aluminum bodied, sealed cartridge damper on the other. The result is superior damping and ride control combined with tunable preload and a new benchmark for high performance suspension on the Dyna platform. This kit can be installed in either configuration, Standard or 1-inch low. The suspension is available for 2008-2015 Dyna applications.