All The Benefits Of The Original Thudbuster Design In A Smaller Package. The Thudbuster St Uses A Shorter Parallel-Linkage Mechanism To Yield The Ideal Suspension Post For Riders Looking To ‘Take The Edge Off’ Bumps With Less Loss Of Weight Penalty. (Eg. Xc & Amp; Road Riders).Shorter Linkage Design Provides 1.3″Of Active Friction-Free Travelthe Single Elastomer Can Be Changedto Fit Your Size And Riding Style454-474G