how do you measure a seat post ???

[jig-sore]

i want to ditch the suspension seat-post on my hybrid, but due to it being a small frame i need to get the right size replacement or i wont get enough height on the saddle.

i know is 27.2mm diameter but how do you measure the height/length ??

most sizes quote about 200-300mm long but is this from the seat rails to the limit mark or is it done some other way ???

 

[wheres_my_beard]

from the seat rails to the limit mark

That would make sense; so you buy a post knowing what it's useable length is.

I'd suggest getting one that is longer than you think you need to be on the safe side.

 

[e-rider]

different manufacturuers use different reference points so there is no simple answer to your question

I would second the advice about going longer than you need - as the extra length will add very little extra weight and the different length posts usually all cost the same anyway.

The only point to note about buying a long post and using it in a small frame is that if you need to insert a lot of it into the frame the seat tube bottle bosses might prevent it from going down far enough. Alloy posts are easy to cut down if need be.