The IBO speed rating for a bow is reached by shooting a 350 grain arrow at 70lbs of draw weight and 30 inches of draw length. This is important to remember because unless you are shooting the same specs used to attain IBO speed ratings, your bow of choice will not shoot as quickly as you might think..
This is the length of your bow as measured from the axle of the top idler wheel to the axle of the lower cam. When it comes to applying these dimensions to target shooting or hunting it is important to consider how and where the bow will be used..
The term “brace height” refers to the distance between the throat of the bow grip and the string. Brace height is important for many reasons. First, the shorter the brace-height, the faster the IBO speed rating will be. This is simply due to an increase in the bows power-stroke. In other words, the arrow remains on the string for a longer period of time because the string must travel a longer distance..
This is simply the minimum and maximum amount of weight required to bring the bow to full draw. Typically, this weight range is 10 pounds. For instance, a bow with a 60 pound peak draw weight will have a minimum of 50 pounds. Likewise, a 70 pound draw will carry a minimum draw-weight of 60 lbs. Overall draw weight can be increased or reduced (within this 10 pound range) by simply tightening or loosening the limb-bolts on each limb..
This is the actual weight of the bow. Bowhunters who typically hunt in demanding terrain will often favor a lightweight setup such as the all the new Mathews Heliu-m- weighing in at a remarkable 3.5 lbs. or the Mathews Jewel, DXT or Z7 Xtreme. Such bows make long hikes over tough terrain much easier as the hunter experiences less fatigue. This can be a real asset over the course of a long backcountry hunt..
The term “let-off” basically refers to the percentage of weight that is subtracted from the bows advertised draw weight. In other words, a bow set at 70lbs, with 80% let-off, will only require that the shooter hold back 14lbs of weight when the bow is at full draw..
In order to reach your full potential as a shooter and a bowhunter it is important to be relaxed and comfortable when executing the shot. To achieve this situation, the bow must fit you properly; i.e. the draw length must be correct..
The bowstring has two purposes. First, it is used to transfer energy from the shooters arms and back muscles directly to the limbs of the bow. This allows the bow to be “drawn” and thus store energy. Second, it is used as a catalyst to transfer that energy from the limbs to the arrow..
* All specifications are approximate.
** Without accessories.