An FSA headset bearing: 52mm outside, 40mm inside and 7mm wide, with a 45/45° contact angle for a 1.5in steerer.

Highlights

• Outside diameter: 52mm
• Inside diameter: 40mm
• Width: 7mm
• Contact angle: 45/45°
• Steerer size: 1.5in
• FSA code: MR170

Details

Headset bearings wear with rain, road grime and pressure washing, and a rough or notchy bearing makes steering feel vague. Replacing the bearing with the same size and contact angle restores smooth, play-free steering.

Angular contact bearings are directional, so fit each one with the angled face matching the cup or crown race, and grease the seats lightly before fitting. Replacing both bearings together keeps the steering even.

Fit and compatibility

It suits headsets that use a 52 x 40 x 7mm, 45/45° bearing. Match the outside diameter, inside diameter, width and both contact angles to your old bearing; the numbers are usually printed on the bearing's seal.

Fitting

A headset needs clean, correctly sized cups and the right preload once the stem is fitted. Our workshop can press it in and set it up for you.

If you're not sure it's the right part for your bike, send us the details and we'll check before you order.