Seatpost measurements

[Pimperial]

Can anybody tell me where the length of a seatpost is measured between? I need to find a long one as my legs are too long for my current frame/seatpost, but when I find a "320mm" one, I have no idea how that compares with my current one.

 

[spandex]

From where the rails of the seat clamp on to the post to the min insert line

 

[Pimperial]

That seemed the most sensible way. Thanks.

 

[02GF74]

From where the rails of the seat clamp on to the post to the min insert line

interesting - I thought it was fromthe centre of the rails to the end .... I have measured posts but now not sure if you are right or not.

 

[youngoldbloke]

I think it is generally the overall length - including the minimum insert.

 

[spandex]

We what is the point of including the inch or two under the min mark when you can not use it!

 

[youngoldbloke]

But you do use it - you could argue that that is the most important bit! By the way is there a standard 'minimum insertion'? (I came to my conclusion about it being the overall length after looking at various manufacturers websites, and it seemed that 65mm, or about 21/2" was a common figure given for min. insert.) Agree it is all very confusing.

 

[skwerl]

it's the total length, which is why you need to know the usable length as well, before you buy. Minimum insertion is going to depend on the material it's made from. You'd think the frame material would also influence this but I imagine the min insertion is just based on the most pessamistic scenario, so that all frame materials are covered.