I need to find a replacement headset for an integrated system "IS". I can get the required dimensions by removing the fork and taking headtube and steerer tube measurements by using a digital caliper. I then compare what I get to possible values listed in this Cane Creek diagram from their excellent Everything you need to know about Headsets:
I figured out that I need a replacement for a IS42/28.6 | IS52/40 but what about the bearings angle? Is there many possibilities for a given SHIS? If the angle is written on the old bearing that is fine, but what if it is not? And what if you do not have access to the old bearings?