August 24, 2021
The dog days of summer are in full swing, and you’re kicked back in the recliner, toying with the idea of buying a new compound bow. You’ve thumbed through a few magazines and read plenty of ink on the websites of your favorite bow builders. You took things a step further and watched some marketing videos and commercials, but you still have questions. Compound bows have a vocabulary all their own, and if you don’t savvy the lingo, making an informed buying decision won’t be easy.
Don’t panic. We’ve put together a quick lesson in compound bow terminology for you!
Commonly misunderstood, axle-to-axle length is not the length from the top of the top cam to the bottom of the bottom cam. This measurement is the bow’s overall length.
Axle-to-axle length is the distance from the axle pin that holds the bottom cam in place to the axle pin that holds the top cam in place. Axle-to-axle length can only be measured accurately when the bow is at its max poundage. Typically, a shorter axle-to-axle bow is easier to navigate in tight places like a tree stand or ground blind.
Limb Stops & Cable Stops
Both are located on the cams, and both do the same thing: stop cam rotation at a pre-set full-draw measurement and create a backwall. The significant difference is limb stops contact the bow’s inner limbs, providing a hard-as-a-rock feel at full draw; and cable stops contact the bow’s cable, which creates a flexible backwall feel.
With limb stops, you can pull as hard into the bow as you like, but you are pulling into something that can’t move. With cable stops, when you pull into the cable, it will move slightly. Some compound cable stops/cable combos move more than others, and this movement is called the bow’s valley. Many thumb and back-tension release shooters prefer cable stops, as they allow the shooter to feel pressure applied to the cable.
Understanding brace height is super easy. Brace height is measured from the string in a straight line to the grip’s deepest part or throat. Traditionally, bows with more extended brace heights tend to be a bit more forgiving. This is because the arrow departs the string sooner, giving the shooter less time to add an element of human error to the shot. More extended brace heights tend to produce a smooth draw, while shorter brace heights tend to make the draw cycle a bit more rigid.
Whitetail hunters should consider a bow with a longer brace height. Why? Likely, you won’t be shooting much past 40 yards. You want forgiveness and a smooth draw, especially when weather conditions are frigid. I consider anything over 6 1/2 inches to be a longer brace height bow, and any measurement below that to be a shorter brace height bow.
Some states have laws that ban hunting with too high of a letoff rating. Letoff is the point during the draw cycle when the bow’s draw weight is significantly reduced. For instance, if you have a bow set at 70 pounds of draw weight, that doesn’t mean you’ll be holding 70 pounds of weight at full draw. Instead, at a certain point during the draw cycle — usually about halfway through — letoff kicks in. You’re pulling the total draw weight while drawing the bow, and as peak weight builds, the bow smoothly transitions to letoff.
The standard letoff rating is 80 percent. So, if your bow is set at 70 pounds of draw weight, holding weight at full draw will be around 14 pounds. An 80-percent letoff is also legal in most states. Many bow manufacturers create bows with adjustable letoff ratings. Letoff ratings can include 75, 80, 85 and 90 percent. Remember to read state game laws before choosing your go-to letoff.
More letoff means less holding weight, but it doesn’t always mean better accuracy. A letoff rating of 75 percent is typically the choice of serious target archers.
Cams are the most complicated part of any compound bow. Most cams have modules that allow for changes in draw length without a bow press. However, some cams come with a module set at a specific draw length, and should you need to change that length, you will need a new module. Pay attention to this when you’re doing your research. A bow’s specific cam system will also allow for letoff change if the cam was designed to allow for different letoff settings.
Cam design also varies by bow. There are cams built for speed and cams built for comfort, and even some that allow you to select between speed and comfort. Whitetail hunters should always go with comfort over speed. You will often need to draw at odd angles, hold for long periods and press your bow into action when Mother Nature is at her worst.
There are also bows with single and double cam systems. Solo cam bows are easy to spot. There will be a single sizeable cam on the bow’s bottom and a simple wheel on the top. Dual cam bows have identical cams on the top and bottom that must be in perfect time for the bow to perform at its best. These cams mirror each other in shape and size.
When it comes to the cam design best for you, I recommend visiting your local pro shop and doing some testing.
Peak Draw Weight
Understanding peak draw weight is essential. Peak draw weight is the bow’s maximum felt draw weight when the limb bolts press the limb pockets flush to the riser. Most flagship bows are adjustable down in weight 10 pounds from the peak. This is accomplished by placing the correct Allen wrench in the limb bolts and turning those bolts counterclockwise. Always remember what you do to the top bolt you must replicate on the bottom bolt.
For instance, if a bow has a peak draw weight of 70 pounds, it’s likely it’s adjustable down to 60 pounds of draw weight. Other bows have a much more comprehensive draw weight range, and manufacturers will note this in the bow’s owner’s manual. Never start backing out a bow’s draw weight until you read the owner’s manual.
A great way to find which draw weight is right for you is to dress in your coldest weather whitetail gear, hold the bow straight out in front of you and draw the string straight back. If this process feels difficult, or if you have to tilt the riser up or down to get the bow to full draw, you need to go down in weight.
This is the total weight of the naked bow. By naked, I mean with no accessory items attached. If the manufacturer lists the bow’s weight at 4.3 pounds, that is its naked weight. When you start adding a sight, rest, stabilizer and quiver, the overall weight is increased.
Is there other bow lingo you need to know? Yes. You should always be reading and learning, but the above will help you get into a whitetail bow that feels like it was made just for you.