Headset Scott sub 30

[find_bruce]

My commuter is a 2009 Scott sub 30 & is showing the usual sign of a worn headset, but I'm struggling to figure out what I can buy as a suitable replacement. Best description I have found is "Ritchey OE Logic Zero, semi integrated" I am assuming zero refers to zero stack

Internal diameter is easy - its a 1 1/8" straight steerer.

What else do I need to know to find a suitable headset.

[Duck!]

Semi-integrated means it has cups pressed into the frame, then the bearings fitted in the cups. A fully-integrated headset has the bearings directly fitted into head tube's machined cups.

[find_bruce]

Semi-integrated means it has cups pressed into the frame, then the bearings fitted in the cups. A fully-integrated headset has the bearings directly fitted into head tube's machined cups.

Thanks Duck - can I replace the bearings or do I need a new headset? Either way, how do I figure out what size?

[Duck!]

The bearings may be available separately; they're often - but not always - the same as those in an integrated set. If they're not horribly corroded the size and angles may be legible around the outer shell.

[find_bruce]

Well I feel like a bit of a goose (nothing new there) - took the bearings out to see any markings & discovered that they are not sealed bearings at all & that therefore I should have been greasing them - it seems I did well to get 9 years with zero maintenance.

Despite my neglect, they don't seem horribly corroded - are the size & angles likely to be on the outside of the cups if I knock them out ?

[Duck!]

Sounds like it's not only semi-integrated, but also a semi-cartridge type assembly. There won't be any markings on the cups if you knock them out; you'd only find the numbers I referred to earlier on the bearings themselves if they were separate from the cups.
it is almost certain that the head tube bore for the cups is 44mm. Therfore any ZS44 semi-integrated headset can be fitted.

[find_bruce]

it is almost certain that the head tube bore for the cups is 44mm. Therfore any ZS44 semi-integrated headset can be fitted.

You're a champion thanks Duck - cartridge headset purchased last night, fitted this morning & all is good again