I am looking at giant defy 4 s(46.5) and m(50) I am also looking at specialized allez frame size 52 and 54 What I am looking for is the effective seat tube measurement? So am looking for people that could help, if they have these size bikes above could they please measure from the centre of the top tube at the head tube to the seat tube keeping the tape measure vertical with the ground (i.e. horizontal imaginary top tube) then mark the seat post and measure up from the centre of the bottom bracket to this point to get another measurement and please state what this measurement is thanks very much.
