Home mechanics and workshops replacing a worn 34.1 x 46.8 x 7 mm, 45/45 degree headset bearing.
When your steering feels notchy, gritty or clicks as you turn the bars, a worn headset bearing is usually the culprit. This is a sealed cartridge bearing with a 34.1 mm inner diameter, 46.8 mm outer diameter and 7 mm height, the common size for headsets built around a 1 1/4 inch steerer.
It has 45 degree chamfers on both the top and bottom, which is what lets it sit correctly in the frame's bearing seat and against the crown race or compression ring. A dust seal helps keep water and grit out.
Headset bearings are sized by these four numbers, so check them against your old bearing (they're usually printed on the side) before ordering. Get them right and it's a straight swap.
Sealed cartridge
Dust seal helps keep grit and water out.
45/45 degree chamfers
Matches common integrated and semi-integrated headset seats.
1 1/4 inch steerer size
34.1 mm bore suits 1 1/4 inch headset setups.
Easy match
Size is printed on most original bearings for a quick check.
Bearing
Great for
Maybe not for
Fits bearing seats that take a 34.1 x 46.8 x 7 mm, 45 x 45 degree cartridge. Compare all four measurements with your old bearing before buying, as nearly-matching sizes won't seat properly.
Check before you order
Pull the old bearing out and read the side: headset bearings are usually marked with their inner diameter, outer diameter, height and angles. If the markings are worn, measure with calipers.
Fitting tip
Clean the frame seat and crown race, add a light film of grease, and fit the bearing with the chamfers facing the right way. Preload the headset just enough to remove play without the steering feeling tight.
