The new GRX wheel supports gravel rides that are faster, further, and more fun. Wider tires need wider rims to maintain lateral tire stability at low air pressures. Shimano studied the complicated relationship between tire size, rim width, air pressure, and tire lateral rigidity to optimize the GRX rim width for 32-50c tires. In addition, we pursued the best balance of rim weight, strength, and profile in order to deliver an exceptional gravel wheel.