The seatpost needs to go past the point where the bottom of the top tube meets the seat tube.
Beyond this point butting kicks in (on butted tubes) and unless you have a plain gauge seat tube - pushing the seatpost any further in does not offer any more support.
The seatpost needs to go past the point where the bottom of the top tube meets the seat tube.
Beyond this point butting kicks in (on butted tubes) and unless you have a plain gauge seat tube - pushing the seatpost any further in does not offer any more support.