If my seat tube angle is 76.5 degrees and the nose of my seat is 2.5 cm behind the BB am I forward or back of 76.5? Is there a way to calculate this based on these measurements? I hope this isn’t a dumb question and if you need any other info, let me know. Thanks for the help.
There’s a mathematical formula posted in another thread (by Art Franke, I believe), or if you dread real math like me you can swag it by using the chart in this article:
In order to calculate the seat tube angle you need to know the saddle height measured from the middle of the BB and the middle of the top of your saddle. Send that along and we will help solve the mystery.
AJFRANKE, Thanks for the help, I hope I have the measurments you need. Everything is in inches converted to cm’s (1" => 2.56 cm’s). Any questions or if you need more info, let me know.
Nose of saddle behind bb => .1875" (3/16) = 4.8 mm
Middle of saddle behind bb => 5.3125 (5 5/16) = 13.6 cm
Middle of saddle to bb (height) => 30.875 (30 7/8) = 79.04 cm