[b.mcnice]

Sweet spot

I have a 26” draw and I’m on the fence about going with a 23” or 25” oly riser. Of course, I need as much speed as possible to reach 90m. This got me thinking about other sports and the idea that there exists a sweet spot in archery bow lengths relative to draw length. In other sports such as golf there is a sweet spot on the face of the club and length of the club to hit the ball (alike baseball and tennis), springboard diving has a sweet spot where to jump on the board, bowlers have a sweet spot to strike the pins based on many variables, etc. I was wondering if archery has an optimal draw length relative to riser size and limb length? If so, can someone help me out? Sorry if I got any of the analogies messed up for those who play the above mentioned sports.

Riser Limb BowLength Optimal-draw-length?
23” Short 64”
23” Med 66”
23” Long 68”
25” Short 66”
25” Med 68”
25” Long 70”

If there does exist a sweet spot relative to draw length, then what if any difference exist between overlapping bow lengths such as 23” riser, med limbs and 25” riser, short limbs (or 23” riser, long limbs and 25” riser, med limbs)?

Truth be told, I really like this one riser at my local archery shop but it only comes in 25”. It's likely the 23” risers will fit me better (because it doesn't weigh as much and I'm weak), but I will only go with the 23” riser if performance greatly suffers (missing the draw sweet spot on the limbs/bow).

 

[Brandeis_Archer]

I'd say our (most important) sweet spot has to do with the arrow spine, obviously. Other sweet spots may deal with stabilizer setup, tiller, brace height, etc.

However, (bow efficiency aside) I dunno if there would be a catch-all between riser+limb combo and draw length. There are guidelines, sure, but between different limb and riser geometries, there may be several setups that will work for you.
For example, with my 31" draw, guidelines say I should be using a 25" riser and long limbs. However, my Fiberbow has an extra half inch-ish of deflex (comes from the riser itself, and I've also modified the grip a touch). Even with that (so consider my draw length 30.5") I should probably be using long limbs, but since I haven't felt any stacking, medium Innos work just fine for me. If I went to different limbs (or wanted to crank them in a few turns, putting more pre-stress on them), I might have to use longs.

I would view the sweet spot as utilizing fully the equipment without overstressing it. In other words, if you draw much further, the system starts to stack. It would not make sense for a person with a 24" draw to use a 70" bow, because without a doubt, the best working range for that system is going to several inches longer. A shorter bow (66 or 64") would likely serve the archer more efficiently. Whether it would shoot any more accurately, that's a question I'll leave to the reader. :tongue:

In your case (wanting to use the 25"), guidelines would probably suggest a 25" riser with short limbs, but I know people using medium limbs at that draw length with no trouble. You may also want to take into account resale value of what you plan on purchasing; I'd think that short limbs and 23" risers might be harder to sell.

-James
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