Headset bearings don't announce themselves when they're working properly—you just steer and the bike responds. When they start to go, though, you feel it immediately: indexing as you turn, notchy resistance through the crown, or play that shows up when you grab the front brake and rock the bike forward. The Ritchey Comp Upper Bearing is a direct replacement for the top position in IS-42/28.6 headsets, sized for the integrated headtube standard that's become common across road, gravel, and cross frames using a 1-1/8" steerer.

The IS-42 designation refers to the 42mm bore diameter of the headtube's integrated bearing seat, while 28.6 matches the standard 1-1/8" steerer diameter. This combination appears in countless frames from various manufacturers, making the bearing a widely applicable replacement part. Ritchey uses a steel cartridge bearing assembly with a 45-degree contact angle, which distributes steering loads across the bearing races more effectively than shallower angles while maintaining smooth rotation under normal riding conditions.

Replacement makes sense when you notice the symptoms—contaminated or dry bearings create friction you can feel through the bar, and worn races develop play that affects handling precision. Since headset bearings sit exposed to road spray, sweat dripping down the steerer, and whatever weather you ride through, they experience contamination that chassis bearings never see. Having the correct replacement on hand means you can swap the bearing during a standard service rather than riding compromised steering until you source the part.... Read More