e.thirteen's technical director Dave Weagle developed the suspension kinematics for the now legendary World Cup and World Championship winning 2003 Iron Horse SGS. Our 2003 Iron Horse SGS rear suspension upgrade makes huge improvements in rear suspension strength and stiffness over the 2003 factory linkage. The improvements were so well received, that Iron Horse decided to ship this linkage and chainstay system with all 2004 SGS frames as stock equipment! The SGS linkage kit includes a new 3-piece top link set, new super-strong chainstay assembly, and new MAX type long life bearings. It should be used with stock hardware. Raced to podium finishes in 2003 by Sam Hill, Nathan Rennie, Bryn Atkinson, Jared Graves, Eric Porter, Kyle Ebbet, and Heikki Hall in 2003.