measuring geo w/ horizontal dropouts

[lanton]

Is there a standard way of taking geometry measurements on a frame with horizontal dropouts? I'd like to make a list of accurate and easily comparable measurements off my bike and I'm not sure how measurements relating to the changeable position of the rear wheel axle are normally made. Is chainstay length the distance from the center of the bb to the center of the axle?

[zap]

Yes, ctr-ctr. Take the measurment with the rear wheel in the favored position.

[lanton]

But is there a "standard" position or way of making this measurement, like with the axle as close as possible to the middle of the dropout and then measuring a straight line perpendicular to the axis of the bb and axle?
I want to get standard measurements from a bike I have access to and can measure myself in order to compare to the measurements of other bikes with or without horizontal dropouts that either don't exist yet or I don't have access to.
(It seems like changing the position of the axle from the rear and highest point of the dropout to the front and lowest position would also change slightly the bb drop measurement and maybe very very slightly, the trail measurement.)