Home Vision World Multimedia On board with EF: #2 - Metron 55 SL Disc 15 May 2021 On board with EF: #2 - Metron 55 SL Disc Thanks to its lightness and aero attitude (55mm depth rim), Metron 55 SL Disc has been protagonist on the Ronde van Vlaanderen and Paris-Roubaix cobblestones, as well as the flat and mixed stages of Tour de France!