Seat post woes

[finch]

Bike in question is a Pinarello Galileo C. Mid 2000s - it had one of those carbon wrapped seatposts (31.6) which ended up seized. On removal the carbon sleeve split leaving a slightly narrower alloy post behind

Now the owner wants to put a new black alloy post in it so ordered one and asked me to fit it . The post will NOT go in the frame - it fits fine in other 31.6 frames

I’m absolutely stumped as to what’s going on - I don’t have callipers to measure but they “look” the same end to end but the new one won’t play ball

[Cudzoziemiec]

Could a bit of the carbon wrap from the seized post be still stuck inside the seat tube?

[finch]

I had considered that but I can’t see anything. Didn’t pimpyrello used to use 31.0 ? Which may explain why a 31.6 was stuck and the spreading of the top might explain why a new hope 34.9 clamp won’t fit

[finch]

Hmm , interwebs say some “were” 31.0 - where the bloody hell do you get a cheap post that diameter - maybe the best thing would just be to shim it and stick a 27.2 in it

[mzjo]

Hmm , interwebs say some “were” 31.0 - where the bloody hell do you get a cheap post that diameter - maybe the best thing would just be to shim it and stick a 27.2 in it

Hollandbikeshop on the continent have an enormous range of seatpost sizes (at an enormous range of prices). I think that SJS used to be pretty good on that sort of thing but it hadn't occupied my thoughts before they were barred to me by Brexit. There must surely be others stocking this sort of thing in UK.
https://hollandbikeshop.com/fr-fr/selles-et-tiges-de-selle/tiges-de-selles/toutes-les-tiges-de-selle/?page=1
I selected 30.0mm but I don't think it has come out that way in the link.

[finch]

Thanks for that - I’m thinking at 31.0 then a 30.4 or 30.8 shouldn’t be too much of a bugger to clamp well

[mzjo]

I have just looked again at my link, their sizes stockés go from 30.9 straight to 31.2. 31.0 may be a phantom size or just unobtainium.

[finch]

Yeah it’s definitely a weird size , just ordered an el cheapo 30.8 and I’ll clamp it hard with some grease and it should at least not get stuck again

[Lightning Phil]

Here you go, 31.0mm and £14.99

https://www.sjscycles.co.uk/seat-posts/250-humpert-patent-seat-post-black-350-mm/

[finch]

If the latest attempt doesn’t work then I’ll grab one of those Phil - thanks