The rim dimensions have not changed (30mm depth, 17mm wide) as they offer an exceptional balance between stability and aerodynamic prowess. The noticeable change visually and when riding is that the rim is made from high-end Fulcrum Twill carbon fibre. This construction dramatically increases the wheels overall stiffness and durability and to add to the this, is also features Fulcrum AC3 braking track technology for superb braking performance. Performance Increase The Racing Zero Carbon is suited to any race event. Perfectly at home on tough climbs, high-speed descents, Gran Fondo events and endurance challenges. These wheels will boost your road riding experience and increase your performance from the first pedal stroke ... More info