Headset FSA NO.55R/558 1.5 ACR Retrofit w/TH-874-1 B1

Headset FSA NO.55R/558 1.5 ACR Retrofit

The FSA NO.55R/558 1.5 ACR Retrofit headset is designed for frames with a 55.8 mm outer diameter head tube. Featuring FSA’s ACR (Advanced Cable Routing) system, it provides a clean and integrated cockpit solution for road, MTB, gravel and cyclocross bikes.

This headset uses angular contact bearings with black seals for smooth steering performance and long-term durability. It includes a durable alloy top cover and is compatible with 1-1/8" to 1.5" tapered forks.

FSA ACR technology allows streamlined cable management while retaining a standard stem, making it an ideal upgrade for ACR-ready frames.

• Type: ACR retrofit headset
• Head tube: 1.5", 55.8 mm OD
• Fork compatibility: 1-1/8" to 1.5" tapered
• Bearings: angular contact ACB
• Bearing angles: 36° / 45°
• Top cover: alloy
• Cable routing: external
• Stack height: 6.5 + 0.5 = 7 mm
• Weight: 101.4 g