Originally Posted by
ejewels
Agreed, I was asking more about where one should measure that angle to... (the top tube or horizon/floor).
One does not simply "measure" the "angle" ..... said Boromir. And he died, pierced by many arrows.
Seriously ... get on the bike. get comfortable. if you cannot get comfortable, move the movable bits.
Rules of thumb are fine ... if you are a thumb.
General ideas are great, generally. Only you know what works for you.
I would tell you my "Perfect Bike Fit Secrets™" but everyone here would disagree ... with me and with each other.
The last time I heard that "45 degrees" line was in a spin class ... where nothing but aero matters.
I tend to set up my bikes so I am comfortable after as long a ride as I can ride comfortably ... and then start removing spacers 5 mm at a time. At some point my girth or my age will force me to stop ... and then, over time, likely reverse that scenario.
That is the "system" which makes sense to me.