Just checked and my seatpost at full height is 9cm above the minimum insert. Should I go for a shorter seatpost for my new bike? (Thomson 410mm vs 367mm) or play it safe with a longer one??

Just as long as the min. insert is in the frame and, preferably, the seatpost extends below the toptube/seattube junction you're all set.

Remember longer posts can be cut, but shorter ones can't be lengthened.

Get a shorter post if you have suspension/interrupted seattube issues or if you feel you need to save a few grams…

a: (weight weenie) yes
b: (normal person) no

simon
thats what I thought 🙂

Might depend on how far down the inside of the seat tube gris the post, some new Fisher frames have very short inserts so even with lots of post "in" the frame they still can crack!

SSP