FSA No.55R Headset - ACR | 2.5mm | tapered | 1.5"

Internal cable routing has never been easier!

Innovative, fully integrated aluminum headset for tapered steerer from 1 1/8 inch to 1.5 inch with upper cap and high-quality aluminum crown race. Upper bearing 1.5 inch - 45°/45° for high stability and durability. Bottom bearing 1.5 inches - 36°/45°. The No. 55R has the following bearing installation dimensions - 55.8 mm.

Details of the FSA No. 55R Low Stack Headset

• ACR top cap 2.5 mm
• Angular contact ball bearing
• Upper bearing - TH MR261A | 1.5" | ID42 45x45 SCB
• Lower bearing - TH MR127 | 1.5" | ID40 36x45 G5

Aero Cable Routing System

The ACR system is a fully integrated and therefore aerodynamic cable routing solution that routes all cables and wires internally through the handlebars, stem, and headset.
This innovative, patent-pending system is unique. It combines experience in the development and manufacture of headsets and cockpits with the aerodynamic optimization of bicycle parts.
The core of the ACR system is the headset and stem, which offers frame manufacturers a simple "plug-in" solution for clean and easy cable routing. By using standard headset dimensions, the system does not alter the stability of the frame, and routing the cables through the headset preserves the round cross-section of the steering column.

Ahead headset designs:

Ahead headsets are divided into the "classic" version, the so-called semi-integrated "Press Fit" and the fully integrated "Drop In" headsets. In the "classic" version, the bearings are located outside the steerer. In "press fit" and "drop-in" headsets, the bearings are located inside the steerer, which results in a lower overall height. Unlike "press fit" headsets, "drop-in" headsets no longer need to be pressed in as usual. The bearing surfaces are already incorporated into the steerer at 36° or 45°. The most common "drop In" types are "Drop In Campa" for Campagnolo hidden sets and "Cane Creek. " For more specific questions about your bike, please contact our service team.