Vogtland lowering spring kit 951600 fits BMW 1Er, F20 / F21. VOGTLAND sport springs, manufactured in Germany, provide multifaceted improvements for your vehicles suspension. The comprehensive design generates a better overall appearance while making a significant improvement in performance. The compound spring rate allows for comfortable ride quality under normal driving conditions while providing maximum performance when being pushed to the limit. Drop front: 35mm Drop rear: 35mm Front axle load: Rear axle load: Vogtland product code: 951600 HSN TSN: 0005/BMG, 0005/BLQ, 0005/BIG, 0005/BLF, 0005/BKX, 0005/BGK, 0005/BGL, 0005/BLG, 0005/BLN, 0005/BGM, 0005/BGN, 0005/BLH, 0005/BGP, 0005/BLI, 0005/BGO, 0005/BLJ, 0005/BLK, 0005/BGQ, 0005/BLM, 0005/BIH, 0005/BIF, 0005/BLO, 0005/BLP, 0005/BIE 1 – The measure of the lowering will be reduced by the measure of the original sport suspension. 21 – All wheel/tire combinations are allowed which are released by the wheel type testing institution. The conditions in the wheel approval have to be kept, except when original suspension is required. 1er, F20 / F21. BMW 1 F20 / F21, Typ 1K2, 1K4. VOGTLAND compound Spring Rate As the distance of spring travel reduces, the performance demands of a spring drastically increase. Derived from racing, the VOGTLAND compound spring consists of two different spring rates. The initial rate provides the proper preload necessary for proper suspension function during all road conditions, and the final rate is designed to provide the appropriate vehicle balance for neutral steering characteristics. Each spring is calibrated for every specific car model, and provides a balance between performance and comfort.