No not a comment on obesity in archery but a quick look at how weight in many different forms can effect archery, whether we are talking about the draw weight of your bow or the weight of the arrows used.
So when can too light be a bad thing, and again I’m not talking about the archers weight here or anorexic, but in fact arrow weights.
Before I launch into this article though I’d like to thank my guest co-author another Rob, Rob Cook.
As many of you know I’m a big traditional archer shooting wooden bows and wooden arrows, so when it came to checking my facts with carbon arrows and so on, so I enlisted Robs help. Rob was also one of the originators of the new Traditional Bow hunter class in the NFAS and has extensive knowledge on the bare bow scene.
Bow International ran an article a few issues back on the effect of arrows weights on arrow flight and I know other sites including The Push have talked about the importance of matching your arrows to the bow.
Too light an arrow and archers can encounter several issues. Light arrows can fly faster and some say further, but they can be affected by wind to a greater degree. also there may not be the mass weight to absorb the energy from the bow limbs on release as effectively. in essence its like a mini dry fire.
Most bow manufacturers will specify an optimum mass weight for your arrow and if you look on just about ever carbon arrow in production will give you an arrow weight in grains per inch
To give you an example of what I mean, a bow maker might say the arrow should be 9 grains per pound of draw weight, so for my draw weight of 45lbs that would be 405 grain arrow weight. Through a lot of trial and error I have found an arrow round 450 to 460 works best from the bow, anything below 420 and the bow becomes noisy and the arrows don’t perform as well.
Rob has created this table of data on different arrow specs and weights for some of the more common arrows on the market. We’ve used a 100 grain pile in all the arrows below calculations and show two lengths 28 inches and 30 inches, so we can give a total weight. To keep it simple Rob has used a 45lb bow weight for spine as I used that weight in the above calculation. It should all make sense but if you have any questions let us know.
|Manufacturer||Shaft Type||spine @28||Arrow Weight||gpp||spine @ 30||Arrow Weight||gpp|
|Carbon Express||Predator II||2040||354||7.9||2040||370||8.2|
|Easton||5MM Axis Traditional||600||357||7.9||600||373||8.3|
|Easton||ST Axis N-Fused Camo/Axis Trad||600||360||8.0||600||376||8.4|
So why is this so important and why am I bringing it up here on this blog?
The NFAS has seen a new bow style recently, that of Traditional Bow Hunter. This style allows archers to shoot carbon or aluminium arrows off the bow shelf (no arrow rests). It is seeing a number of traditional archers that shoot flatbow or hunting tackle which uses wooden arrows giving it a go. They are buying carbon arrows of the right spine but I wonder if they are considering the effect of shooting lighter arrows on their bows? I was discussing this with a couple of people including Rob, so we thought we would put this together.
It is worth remembering that a lot of traditional wooden bows have not been constructed to take ultra-light carbon arrows often used in target archery or are sold as cheap alternatives to wooden or aluminium arrrows. Please don’t get me wrong some bows have been constructed to take such arrows but not all.
N.B. Adding a heavier pile to the arrow will increase the overall weight but it will also change the dynamic spine of the arrow, making it more flexible or weaker.
So what can you do?
- Check the weight of your wooden arrows and carbons so you know the difference.
- Check what your limb / bow manufactures recommended weights are. Most if not all will have this information on their websites or would be happy to share it with you. After all they don’t want to see you trash your bow as it reflects badly on them.
- Going for slightly longer arrows as this will increase the mass weight too, this is why we have included two sizes in the above table.
I hope this has proved interesting and helpful. I would like to say thank you to Rob for all his help and number crunching with this. He produced a load of data on different arrows in a long excel document, as well as speaking to several bow manufactures to check minimal weights.
Thanks for reading.