Adjusting 2015 Grand Prix Riser for Center

The Hoyt website has plenty of manuals.

If your string is not quite running down the center of your bow and limbs, the Grand Prix offers a single set of adjustment screws.

I decided to adjust the bow while it was strung. There is not much play in these screws. A few adjustments on both sides made my string seem closer to center.

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Adjusting to a Recurve Sight

The sight is a piece of equipment that is optional in recurve archery.  By observation, it looks far less optional in compound shooting since every compound bow I’ve seen has a sight on it.  The sight is a piece of equipment that is fixed to your bow.  If you have a metal riser, you probably have screw holes already drilled for the sight.  If you have a wood riser or a knock down bow, you may not have an option for a sight.  The sight consists of some mechanism for attachment (“mounting bracket”), a horizontal bar (“extension bar”), a vertical bar (“sight bar”), and a scope that travels up and down the vertical bar (“sight pin assembly”).

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Simple sight parts – photo courtesy of Australian Archery

The sight is an interesting combination of relative and fixed instrumentation.  You get the sight roughly in place and then make adjustments up and down the sight bar.  This part can be confusing.  I created this simple illustration to show how moving the sight pin assembly in the direction of the error corrects the position of the bow.  If you start and the arrows are shooting too low, you move the sight pin assembly down.

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Making adjustments to a sight in response to where the arrows go

The adjustment in my illustration are exaggerated, but are meant to show how the sight pin can be used to make an adjustment in the up and down direction of the riser and the bow.  Similarly, if your arrows are going to high, move the sight pin assembly up and that will cause you to tilt your bow down to keep the pin on the target.  There are all kinds of adjustments on a fully featured sight.

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Full featured sight – photo courtesy of Jordan Sequillion

It could take quite a while to get all of these knobs adjusted and dialed in.  It is recommended that you work with your sight a lot to learn how it’s adjustments work and to be ready to shoot at different distances.  Recording your position (horizontal and vertical) is important.  The scope can also be adjusted left to right with other knobs.

If you need to shoot longer distances, you may need to move the site pin assembly closer to you by adjusting the extension bar.

There are lots of adjustments and your sight may or may not have all the features.  More features means the sight is going to cost more.  Materials are either aluminum or carbon fiber.  Carbon fiber moves less, so it is ultimately a better sight, but it costs a lot more too. The sight is probably another example of buy nice or buy twice.

After these basics, find out more at Jordan Sequillion’s site.

About Brace Height

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.

brace-height--illustrated

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.

brace-height--plunger

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.

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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.

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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.

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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.

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Measured at bow grip

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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

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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.

Working On Release

Using Hudl, we were able to see her anchor wasn’t acting as much of an anchor in her shot sequence.  By drawing a straight line down on the video, her release hand was creeping forward.  We talked about it and watched it a couple of times on the iPad.  This is a fascinating age for sports feedback.  When we went out to shoot in the morning, she was able to make a small correction to her anchor by thinking of hooking her mouth.  It got better for her very quickly.

working-on-release

There is more work to do on her shot sequence especially around transfer, but little steps are good progress.

The younger one came with us too and wanted some video coaching.  I took some video, but mostly we’re working on confidence, posture, and safety right now.  She’s a yeoman in waiting.

yeoman-in-waiting

How To Calculate The AMO Length Of An ILF Bow

Modified from Sky Archery.

Olympic recurve bow strings are now using the AMO measuring system.  The length of the bow is determined by adding the distance between the riser bolts to the length of both limbs.  Most Olympic recurve risers are sold in 21″, 23″, 25″ or 27″ increments.  When you buy the riser, you’ll know the size, but in case you don’t you can probably go with 25″ which is the most popular size.  Of course, if you can’t get the riser length, getting the right string will be difficult.

  • Bolt Pattern is the length between Limb Bolts.
  • The Bolt Pattern is 5″ shorter than the Riser.
  • ILF Limb lengths are: Short 23″, Medium 24″, and Long 25″.

Example:

  • 25″ Riser = 20″ Bolt Pattern
  • Long Limbs = 2 x 25″ = 50″
  • 20″ + 50″ = 70″ Bow

So Many Details: Hook and Grip

After my instructor courses, I learned a lot of the details about shooting,  I suspect there is so much more to learn too.  Now, when we shoot at home or even at the range, we work on one thing during the session.  Her coaches told her as much in the first weeks of practice; but, it’s hard to do if you don’t know those details.  Today was the grip part of Hook and Grip.

  
Here’s what is should look like.

 
More on hook and grip 

Beginners Guide to Indoor Archery Arrows

I have finally documented an overview of selecting arrows for indoor target archery.  It is not meant to be super comprehensive, but orient the inexperienced archer or parent to the range of choices, rough pricing ranges, and some example models to look for.  Once you head down the path of picking out arrows, you’ll have way too many options to consider.

Getting Started with Indoor Target Arrows

Getting Started with Indoor Target Arrows

You can click here for a full sized picture: Getting Started with Indoor Target Arrows