There are a lot of terms when talking about recurve bows. Brace height, draw weight, riser height, tiller, ILF arm size, and more. You can find out more about them in this excellent guide from the documents section of this site.
What is Brace Height?
Since the name is “brace height”, you can bet it will include measurement. Knowing what to measure is important. Brace height is the measurement from the string to the deepest part of the bow grip.
It should also be noted that the deepest part of the grip is about the same as the pre-drilled plunger holes of the bow. These holes are generally right above the pivot point of the bow.
In theory, you can measure to either point. It’s a little hard to measure against the bow grip because of its rounded and slippery surfaces. Check your own bow to know if these are equivalent measurements.
Why Does Brace Height Matter?
There are two elements of shooting affected by brace height. The first is arrow speed. A shorter brace height will generally translate to a faster arrow. The shorter height will mean the arrow is pushed by the string for a longer period of time generating faster speeds. The second element brace height affects is forgiveness. Forgiveness is a nice word describing the Archer’s Paradox (find out more from a previous article on this site). The longer the string is in contact with the arrow, the longer the distortions from the physics of the shot are in play. An archer minimizes the physics of archery with better form. For the same reason a shorter brace height generates more speed, it also increases the duration of the time the arrow is interacting with the bow. The longer brace height will mean less time that the bow is interacting with the arrow.
What Is My Brace Height?
Your bow manufacturer will list the brace height range for the riser and the limb combination. Each will be different, but it will be a range. You can choose the brace height depending on your goals listed above. If you can’t find your particular bow, you could follow the general guidelines below.
From Lancaster Archery
Another method to determine the appropriate brace height is to measure the length of the bow and divide by 8.
How do I Adjust My Brace Height?
You’ve bought the correct size string (or can find out more in the article on AMO sizing from this site). How can I change or adjust the brace height? The answer is pretty simple, you twist or untwist the string. As you can see in the photo below, the string fibers are twisting. The twisted string will be a smaller string. A smaller string will mean a taller brace height. An untwisted string will be a longer string. A longer string will be a shorter brace height.
It’s a pretty good trick if you can twist both sides of the string at the same time. You can work on just one side to make it easier.
What Equipment Do I Need?
You can do this with a regular ruler, or you can buy what is known as a bow square. The bow square will help with brace height and nocking points. The bow square will also clip to the string at a perpendicular angle giving your a more consistent measurement.
Measured at bow grip
Measured at plunger hole
You can get a bow square at most archery shops. Here’s a common one from Easton available at Lancaster Archery
Because you are reassembling your recurve bow on most shoots, you’ll want to check brace height nearly every time. Your bow string will unravel and it will change slightly. Keeping a bow square in your gear bag is a good idea.