What are your thoughts on the ideal string angle for a flat bow? IOW, somewhere between braced and no drawn at all and 90 deg what would be the most efficient angle? OR, maybe there is no such thing?
Well the ideal would be to have the bow limbs stop right at 90 at the end of the archer's draw, maybe 85 to be safe.
Ah, I think I misunderstood the question. You're asking what brace height is best? Don't think there's a perfect angle, depends on the draw length of the archer and the length of the bow...and the profile of the limbs. Lower brace heights or lower angles give the arrow more energy, but may be louder and more shocky. Higher brace is more dead in the hand and quieter, but less energy is transferred to the arrow.
Anything less than 90deg. Different styles of bows have different string angle at full draw and it all depends on the design of the bow. I don't think the string angle matters as long as it s less than 90deg.
Actually was thinking more along the lines of your first comment as well as patb's. I was thinking somewhere between 70 & 80. Was under the impression that much lower than that could result in a loss of efficiency.
That all depends on the design. If the bow is designed with it's max efficiency set with 40deg string angle at full draw(say 28")then it's max efficiency is obtained at full draw. Some of the Asiatic horn bow have very low string angle because the siyahs tips are way forward of the handle.