You are reading a single comment by @gbj_tester and its replies.
Click here to read the full conversation.
-
Is there a "standard"
There are two main standards, 41.0mm OD with 36° internal chamfer, and 41.8mm OD with 45° internal chamfer, sometimes called Campagnolo or Italian pattern. Both have 45° external chamfer. Bearing thickness ranges from 6.5mm to 8.5mm, a correct match being more important for the lower bearing. There are other patterns, but they are rare and considered obsolete.
gbj_tester
Nef
Is there a "standard" 1 1/8 internal headset bearing size?