Shimano does not publicly share sales numbers, but road product manager Dave Lawrence says disc brakes are certainly overtaking rim brakes this year.“It is across the board, not just high- or low-end bikes or groups,” Lawrence says. “It really ramped up in the second half of 2017, both OE [meaning original equipment sold to bike brands] and aftermarket. We have not been able to meet demand for Dura-Ace and Ultegra hydraulics. There is a good chance we will see disc eclipse rim brake in total sales in 2018.”