Originally posted by fujimo:
for some obscure, and mystical reason, draw length is measured from the back of the bow, to the groove in the arrow nock :D
It's probably not as mystical as it seems. I suspect that what they did was just figure out how thick the handles of most bows got and just ran with that number. This was probably done so all the measures from a customers point of view match up. Mostly because a customer likely won't know as much about bows as a bowyer. This way a customer, knowing his draw length is, lets just say 26", can get a bow with X# @ 26" and 26" arrows and everything should work together fine most of the time.
If you're not going to sell your bow, measure it however you like. I'm using the AMO standard myself. How I do it: I have my tillering tree marked in 1" graduations from the belly side of the handle. Then, I figure out what I call an offset for this bow. Since I know how my handle is going to be carved before I tiller, I can know to subtract how deep the pivot point is from my current measure then add 1.75" and keep that number in mind when I'm working the bow.
So for example, suppose that I'm working on a bow that will have a simple rounded handle 1.25" in the middle the handle, in its uncarved state is 1.75". I know that my pivot point is going to be 0.5" higher on the tillering tree than where the bow actually sits. So from there, I subtract 0.5" from 1.75" to get 1.25" and while working on this bow, I know to add 1.25" to every draw. So if I want to pull the bow back to 26", I pull until it's 24.75" on the tillering tree, giving an AMO 26" pull.