Full Speed Ahead NO.55R/57-A Headset

A Zero Stack (ZS) design means the headset cups are pressed inside the head tube rather than sitting on the outside. This results in a cleaner, lower-profile look and helps keep your handlebar height lower, which is ideal if you are trying to dial in a more aggressive riding position.

This headset is designed for frames with a 56mm inner head tube diameter and a 1.5-inch tapered steerer tube. Before purchasing, verify your frame's specific headset standard, as 'ZS56' refers to the internal diameter of the head tube where the cups are pressed.

Angular contact bearings are specifically engineered to handle the combined radial and axial loads that occur when you steer and hit bumps. They provide a smoother, more consistent feel under pressure compared to standard cartridge bearings, which helps maintain precise steering control.

These are sealed bearings, meaning they are well-protected from dirt and moisture right out of the box. While they require significantly less maintenance than open-bearing systems, it is still good practice to inspect them for grit or play during your annual bike service.

This headset uses a 40mm crown race diameter, which is the standard size for a 1.5-inch tapered steerer tube. Ensure your fork's crown race seat matches this dimension for a proper fit.