Proven aerodynamics and an extremely lightweight are combined in the new f4r making it the best choice for an all round wheel set ffwd darc darc stands for double arc which is the profile of the rim it compresses air on the rim to create a faster airflow which reduces the drag behind the wheel improved ffwd hub set ffwd wheels is constantly looking for improvements to offer better quality by searching for or developing the best possible parts ffwd wheels cooperated with dt swiss to