I know that generally it’s said that more seatpost extension is more comfortable because it’s an unsupported beam.
But how much is too much? I suppose it’s a somewhat complex equation of seatpost diameter and rider weight though…
Mainly for me I’m not sure how long I want my seat tube to be on my first frame. All I know is that for my saddle height of 710mm and 27.2mm seatpost, a 58cm seat tube is horrible and harsh and 55cm feels alright. 51cm with a 25.4 seatpost I think felt lovely but that was a while ago and 48cm and a 30mm seatpost didn’t feel as flexy as I thought it would.
I was thinking something like 50-51cm would probably be right for my first (road) frame, but I really like the look of the sketch with a low slowing top tube resulting from a 48cm seat tube. Should I just go for it? 48cm?