Original Thorn Audax - what seatpost size?

[zerogravitas]

Hi all, wondered if anyone can help me with this - I just bought a Mk1 Thorn Audax frame and fork (with the Reynolds variety pack tubeset 753/708/653/531!) ..sadly without seatpost.

I have a 26.6 post which fits but seems slightly looser than I would like and I'm wondering if anyone out there has one they could measure for me or knows the spec?

All the best!
Gabe

[Mr-mac]

27.2

[zerogravitas]

It seems my frame probably had an undersized post fitted in the past with the collar overtightened to try and secure it. The collar lug 'ears' had been bent in quite a way and didn't look quite right which was why I asked the question.

Having gently pried them open now it does indeed fit a 27.2. 

Turns out mine is actually 27mm. I suspect there may be a couple of variations out there.