Head tube size

[TheBALDpuma]

Hi all,

I am selling my Stanton Slackline on eBay, and have just been asked what the head tube size is... specifically that it is not 1.1/8th only. I bought the bike second hand and have no idea. Any ideas on how I can check this?

Also, is there a way of finding out what year the frame was built?

[Kermit power]

A bit of googling suggests that the Slackline 631 has a 44mm headtube (so can take tapered steerers, which I guess is what your questioner wants to know), but the 853 is 1 1/8".