Replacing seat post on Dahon Speed Pro TT

[markk]

I've got a new carbon fibre seat post, to replace the one on my Dahon Speed Pro TT. That way, I can fit a more comfortable saddle with conventional clamp. The new seat post is 33.9mm, but looks a fraction bigger than the original, also meant to be 33.9mm, and won't fit. Is removing the seat post shim an option, or will that mean the seat post will slip?

 

[Cycleops]

Maybe the original isn’t 33.9mm. Check with a micrometer.

 

[raleighnut]

Normally a shim is used to enable a smaller seat post to fit.

 

[markk]

Thanks for the replies and suggestions. Both old and new seatposts are labelled as 33.9mm. That said, the original appears in reality to be slightly smaller, so requires the shim. I'm wondering if removing the shim will work with the new seat post.

 

[Anaesthetic]

I've got a new carbon fibre seat post, to replace the one on my Dahon Speed Pro TT. That way, I can fit a more comfortable saddle with conventional clamp. The new seat post is 33.9mm, but looks a fraction bigger than the original, also meant to be 33.9mm, and won't fit. Is removing the seat post shim an option, or will that mean the seat post will slip?

I have a Dahon Pro 20 and have found that replacement seat posts don`t always fit the seat tube when using the original seat shim. Either you have to use coarse grade emery paper to rub down the original shim to make it fit with the new seatpost (don`t rub down the new seatpost!), or you have to find pliable aluminium sheet in a thickness that allows you to make a new shim to fit between your new seatpost and the seat tube in the frame.
Personally, I have rubbed down my original seat shim and it worked perfectly.........it took a little time, but it worked well.

 

[markk]

Belated thanks for the advice and suggestions. It turned out I'd been sold a seat post that wasn't the advertised size: 34.67mm instead of 33.9mm, whereas the original was 33.78mm. A new one arrived today from a different supplier and fits perfectly.