Definitely do not measure it to the string on a conventional single cam bow. It will give you a false reading and hours of worthless tinkering...if there is such a thing...
OK, now you guys are going to drive me insane. I checked the tiller on my Liberty going to the bowstring, and its dead on when both limbs are locked down. However, when i run string from the e clips on the left side of the limbs, my top limb is 1/2" longer. Is this normal? Is it right when they are the same going to the bowstring, or did I tune my bow completely wrong? thanks.