Carlton seat post diameter

[Dickladd]

Hi, would anyone know what diameter seat post a 1977 Carlton Circuit should have? I'm building up a bare frame that came without one and measuring the seat tube is proving...inconclusive. Not sure if the tube is distorted but if I'm going to get physical with it, I'd like to be sure I'm making the correct post fit.
Measures 24.6 to 25.48 depending on where I measure!

 

[Spokesmann]

These should normally be around the 1" mark and take a fairly common seat post size as the tubing is only carbon steel like Truwel. Have you checked the inside diameter of the seat tube? I use a bit of light grease on mine when easing in a seat post.

 

[Dickladd]

Thanks for that. It's the inside of the seat tube I'm measuring but it measures differently depending where you take the reading. I'll get hold of a 25mm/1" post and some grease. It's photos of one of your bikes that inspired me