Took my Lyriks outta my Dialled Alpine this morning to give them a quick overhaul. The headset is in a terrible state, and the forks have been in for probably about 6 months now with just a lowers clean and oil change once in that time so I have only noticed the headset woes now.

Checked the lower Cup and it has a matching set of score marks on it. Why would this have happened? Its an FSA Orbit XL II which is the only headset i have been using for well, ever. I think this one was recycled over from the bike the alpine replaced but it was definitely not in bad condition.

Has it been put in at a slight angle?
Is the headtube not 100% straight possibly?
am I worrying about nothing? The marks are very very light in all honesty.

Stick a new headset in and maybe give the steerer a quick rub with very fine sand paper?

I'd say the bearings in the headset have (partially?) siezed and the steerer has been turning in the cage rather than the cage turnign with the steerer.

if it were me I'd change the headset (and crown race) keep it well greased and and not worry too much about sanding down or out – you'll just be takign more metal off for no real benefit.

If you sand it down lightly then you will remove any score marks that could produce stress risers.

I reckon your hedset wasnt in straight and its been rubbing on the cup

Has it been put in at a slight angle?
Is the headtube not 100% straight possibly?

I'd say the bearings in the headset have (partially?) siezed

You'd have felt any of these while riding.

Dunno re cause, may be worth inspecting the cup insert and filing it smooth.

The forks are now undoubtedly knackered. Fear not however as I am prepared to take them off you for a small fee to cover disposal….

thats not ****, just slightly scuffed. i'd be happy riding that.