Post size for 531 butted main frame

[Ed no-more-lemons]

Lazy I know but need to order one and not use existing spares (all slightly too narrow differently)
Looking for calipers and website, recall 27 or 28mm.

Any suggestions welcome

 

[fossyant]

27.2 usually but it can vary

 

[biggs682]

27.2 usually but it can vary

+ 1 re above , three 531 framed bikes in garage and all different sizes so be careful

 

[Fab Foodie]

+ 1 re above , three 531 framed bikes in garage and all different sizes so be careful

This.
I have at least 2 x 531 frames with different sized seat tubes.

 

[fossyant]

Newer tubesets are 27.2 (from early 90's). I've had a Raleigh 531c, Graham Weigh 653 and a Ribble 653 all with 27.2. Same goes with my Columbus SLX

 

[Ed no-more-lemons]

Got a Lovely new Oxford alloy post, although almost as long as the 25" downtube, It may get shortened.
However tis a very tight fit and was thinking of taking some wet and dry paper to it, before smothering it in Vaseline.
Happy days, if I had any wet and dry left, might just have to settle with removing the muck of ages from within the downtube.

 

[alecstilleyedye]

Newer tubesets are 27.2 (from early 90's). I've had a Raleigh 531c, Graham Weigh 653 and a Ribble 653 all with 27.2. Same goes with my Columbus SLX

my claud butler from '51 (remember that?) is also 27.2, the same as my alu frame from 2004…

my deceased 531 frame was different, as again is the '58 carlton…