The Truth About IBO Speed
Compound bows are becoming more and more powerful and bow manufacturers make a point of including the speed of all of the new release bows as part of the vital technical specifications. While the speed that is quoted is accurate, it is not a speed that you will be able to achieve once you have your bow set up. This is something that everyone should be aware of as well as the reason why the speed quoted should just be an indicative figure.
Quite frankly, no one really needs a bow that can shoot arrows at over 350 fps. Game is still going to be shot just as dead with a compound bow firing arrows at 280 fps, but the inclination of the hunter is to buy the bow that is the most powerful and can generate the greatest speeds. It’s part of human nature.
The speed quoted for each compound bow that is released is quoted as the IBO standard rating and the IBO stands for International Bowhunting Organization. By using this single standard the industry is able to provide a fair comparison method that results in all bows being measured under the same conditions.
To arrive at an accurate IBO rating the bow is tested under a set criteria: the bow must be set to exactly 70# Peak Draw Weight, 30” Draw Length and the test arrow must weight 350 grains.
While the basic set up is identical for all bow manufacturers it is obviously going to be in their interests to get the absolute highest possible rating out of their bow so there are going to be a few differences to the way the test bow is set up compared to yours. The test bow is going to have absolutely nothing added to it, no peep sight, arrow rest, silencer or nocking point. The arrow used is more than likely going to be a bare shaft. And the bow will be set to the lowest let-off setting possible. In all likelihood the bow will also be drawn back as far as it possibly can, even beyond the back wall to squeeze out every last possible bit of speed out of the bow.
The point is the advertised IBO Speed is a figure that is almost impossible to achieve when you have the bow in your hands. For starters, the bow is going to be loaded with a bunch of features designed to improve your accuracy, reduce noise and make it feel smoother. All of these factors are going to place small impediments on the bow string that is going to slow it just a fraction.
What you should expect with your fully loaded bow is the capability of shooting speeds anywhere up to 50 fps less than the speed that the bow was advertised with. This shouldn’t actually be something to be overly concerned about and unless you put a few arrows through a chronograph of your own, you are unlikely to know or care about exactly how fast your bow shoots. A modern compound bow shooting around the 300 fps mark is still shooting incredibly fast and will provide you with all of the power you need.