U.S.E. Aluminium SX Suspension 30.0 Seat Post Black Medium - 120-174lbs. U.S.E. Aluminium SX Suspension 30.0 Seat Post Black Medium - 120-174lbs. USE created the world's first suspension seat post 20 years ago. 20 years' later USE continues to develop and produce the world's best suspension seat posts using the latest manufacturing techniques and engineering excellence. The SX seat post provides top-level competition suspension performance, it's similar in construction to the top of the range XCR suspension post and uses the same service kit but uses a different clamp and is produced at a more competitive price point. Note: This size -30.0 is achieved (we can fit any frame size) with a shim on a 27.2 post. All Shokposts are fully serviceable, adjustable for rider weight and give many years of loyal service with comfort, recovery and performance benefits. All posts have a 'Pre-Load Adjustment' screw at the bottom of the post. We can get to fit any frame with a shim !