Boring out a pushbike saddle tube.

[Welderpaul]

When that frame was built, USE seatposts were 22mm. You used [no pun] a shim to fit your frame. There were plenty of people fitting them to frames with the first intersection lower than 3" from the top of the seat tube. Because the seat pist didnt have ant support lower down it would break or bend the seat tube above that first weldment. It may have been a retro fit.

You live and learn

 

[bigegg]

When that frame was built, USE seatposts were 22mm. You used [no pun] a shim to fit your frame. There were plenty of people fitting them to frames with the first intersection lower than 3" from the top of the seat tube. Because the seat pist didnt have ant support lower down it would break or bend the seat tube above that first weldment. It may have been a retro fit.

Definitely 27.2mm according to multiple online sources.
Gary Fisher have never used 22mm (or equivalent) sized seat post that i can find reference to.

I've ordered a 27.2mm one, any way