The unique system was developed and patented by ACROS [ EP1879788 ]. Three lifters create zhe distance to get the headset adjusted through a setscrew - which makes the star nut needless. Thanks to its ingenious effectiveness this system is perfectly suited for carbon fiber steerers and reduces the weight of the total system. THE CLAMP option pack is compatible to our AH-06 and Ai-22 and enables the use of THE CLAMP system also for ahead and semi-integrated bike models. The AH-11 is additionally equiped with a fastener which keeps the previously adjusted bearing preload even without the mounted stem. It is therefor perfectly suited for travelling or frequent transportation in the car. THE CLAMP was used by professional bikers on the famous track Paris-Roubaix and was intensely approved and always attracts attention.