In the past, when rim brakes were the norm and gravel bikes hadn't yet emerged, the width of rims was hardly a consideration. However, in today's cycling landscape, it has become a crucial specification worth noting whether you're in the market for a new bike, wheels, or a set of tires.

Traditionally, the belief among most road cyclists was that narrow tires equated to faster speeds, resulting in rims rarely needing to accommodate tires wider than 28mm. Furthermore, the width of rims was constrained by the space available between rim brake pads. This status quo continued until a series of innovations reshaped the scene.

Firstly, the advent of disc brakes liberated rim design from the necessity of providing a braking surface, allowing for greater freedom in rim width. Secondly, advancements in physics and aerodynamics revealed that wider rims paired with road bike tires often offer improved aerodynamics and enhanced rolling efficiency.