I spend a lot of time on the road for work and spend my countless hours solving world problems and creating new ones.
I know there is a benefit of longer draw. So does anyone actually know what it relates to?
What would happen if a person dropped draw weight and increased length?
Rule of thumb,3 pounds for every inch of added draw. If your bow is 45# @ 28", it would be 48#@29", 51#@30". Now not all bows are the same,it could be 2 pounds or it could be 4 pounds. But you get the idea. Now a longer draw usually means you are makeing the limb work more, in some cases meaning better performance.
It is a factor of string time....that is why 47@28 bests 47@27. If by reducing draw weight you could increase your own draw length you might 'get something for nothing' but you would have to adjust to the form changes too.
I have a short (26") draw to the corner of my mouth. I've tried a lighter bow and drawing back to my jaw just under my ear. This increases my draw length by about an inch and a half, but increases the draw weight by about 4-5 pounds. The bummer is that I'm increasing draw weight and its a bitch to get my accuracy back with that style. I use the term "accuracy" loosely.pup
It's about transfer of energy & power stroke - stored energy is some formula of weight x distance (been a long time since calc). But assuming a 7 inch brace to make it easy - at 27 inches, you have a 20 inch power stroke, and at 28, you have a 21 inch power stroke. If both weights are the same at 'full draw' it takes less energy to reach 47lbs in 20 inches than it does 47lbs in 21 inches - so the stored potential energy is less with the shorter draw.
while it is very possible that 43 @ 28 will equal 47 @ 27, it really does not matter. With every bow or grip design a person will have their own ideal draw length. With straight gripped bows I draw 26&1/4", no matter if is a 90 pound or a 30 pound bow. If I take a target bow, put my weight on the back foot, anchor under my jaw,keep the arm body head and neck straight, I will draw around 28"; but if the deer is not acting like a dead target, it is pretty much safe from me hitting it before it runs away. Always shoot with you most accurate draw length and let the pounds be what ever you are comfortable with using at that draw length.
I would say 5% more/less drawweight for very inch you draw more/less then the drawlenght/pondage for which the bow is specified.
Drawlenght will affect the dynamic spine of your arrow.
Every bow has a drawlenght at which it performances optimal, like a sweet spot.
That's all there is to it!
Bjorn and txnrog thats what I was thinking...
If a person can, for the same effort pull a lighter weight farther, and increase bow efficiency, it seems like a good trade. "Something for nothing" like Bjorn stated. Of course there would be a new anchor point requiring slight retraining, but also some of the increase in draw length would stem from slight alterations in joint angles that are needed when pulling a bow closer to your perceived limit.
Like I said, I completely understand that matters about as much as a sack of old socks to most. I dropped down weight about 10 pounds and gained an inch of draw length doing so. I draw a good 27 inches now and was wondering what would happen if I dropped 5 more to around 42 pounds and gained another inch.
I'm an exercise physiologist and currently in nursing school. So I'm looking at this mainly from the physiological efficiencies gained. I won't bore yah with that though.
This is hugely relevant especially as we get older........what is the point in shooting a 70# bow if your shoulder is collapsed, elbow way too bent, and your head is tilted way forward to compensate for the heavy load?
Been there! :bigsmyl: :banghead:
night owl - it really isn't 'something for nothing' as you still have to impart more energy into the system at the greater length to get more energy out of it- it's just that most people will percieve it as easier since the peak weight is lower.
So how much faster would a bow that is 50#@31" be than one that is 50#@28"?
Looper, with the three extra inches of drawlength, it would be substantial, probably around 15 to 20 ft/sec. I've heard, but can't verify, that one inch of drawlength is equal to 5 pounds of draw weight.
How fast your bow is, is also determined by the weight you shoot and the string you use.
My bow delivers only 38# at my drawlength, but puts a 190+ fps on the chrony. I shoot 9.4 gpp and use a ultra skinny (6 strands) string with padded loops.
That is one big reason why the so called Asian bows seem more efficient at lower poundages with the traditional thumb draw at 30+". I think I read some study that an inch of draw lenghth adds as much as 10# of kinetic energy.