Basic Bow Tuning

by Cujo Cooley
BowCountry.com Staff Writer

Here I will attempt to share some of my knowledge with fellow archers in hopes of helping shoot better scores, bag more trophies, fill the stew pot, and help your bow shoot the best it possibly can.

This time out, we'll start with basic bow setup and tuning. Many of you will no doubt be past this level, but for the beginning shooter, or the seasoned veteran wishing to learn to do some of their own work, I think it best to start at the beginning. It is important to bear in mind that these tuning points are the beginning of a tuning process that can go as far as need be. This article illustrates the sound fundamentals of basic bow tuning. While many others and I use more advanced tools and techniques for more advanced level tuning and shooting, it should not be construed, in any way, that these methods are either ineffective or unsound.

Tools for Tuning

First, a few simple tools are necessary for accurate tuning. A bow square, a set of nock pliers, a center shot tool, and a pack of allen wrenches are the minimum tools required. If you are interested in more advanced tuning, a quality double pull bow press is a must. These items should be available at any quality Pro Shop, or via mail order from a reputable source. I would also suggest a bow vise and notebook if you intend to do any amount of work that requires more than just the occasional quick fix. The bow vise will hold the bow for you as you wile away the hours tinkering, and the notebook, (if you write down every thing you do), will help you get back to where you started should the tinkering not give you the expected results.

One-Cam versus Two-Cam

For many of us, the one-cam bow has become the bow of choice in today's world. Simplicity of tuning, ease of shooting, and impressive speeds have all combined to make the tried and true, trusty two-cam bow seemingly drop from existence. However, for all its hype, the one-cam bow does have a few tricks up its sleeve that most archers are not aware of. Cam timing, nock setting, brace height, and axle to axle length all play a major role in how any bow shoots. I'll not get into the nightmare of which is better, but suffice it to say that in today's high tech bow marketplace, either is a fine choice. Personal preference will ultimately decide which is better for you. Two-cammers generally are faster, all other things being equal. Some would also argue the accuracy superiority of a two-cam versus a one-cam. Suffice it to say, that any of the top line bows available today, with either cam design, is capable of out shooting any of us.

One-cam bows need to have a steeper valley to get the speed associated with a two-cam, and as a result, the one-cam draw cycle can be a bit tougher feeling than a two-cam. While speed is not everything, comfort is, and there is a difference in how the two designs feel during the draw and during the shot.

Now, on to the tuning...

Assuming a passing grade on a qualified safety check, which would include, among other things, string and cable condition, cam condition, limbs, riser, axles, etc. After the successful determination that the bow is indeed in a shootable condition as well as an accurate draw length and proper poundage are set, the next logical thing to do is look at the total bow and arrow package. Having already looked at the bow, the next step is the arrows.

Does Your Arrow Match Your Bow?

It is imperative that your bow and arrow combination match. As a pro shop owner, I have seen countless new customers walk into my shop and tell me that not only can they not hit the same spot, but they can't hit the same county with two arrows at 20 yards. Many times, I can fix the whole thing by just getting the right arrow for the application. Pay attention to the arrow charts! That is what they are printed for. Cam style, arrow length, poundage, and point weight all play vital roles in how an arrow will fly from your bow. All the top arrow manufacturers provide arrow charts with detailed directions on how to read the chart and select the correct arrow for your setup. A competent archery shop should always double check your setup to determine the correct shaft selection.

Get the Timing Right

We'll take a look at cam timing in this step. Most everyone is familiar with two-cam bow timing and it can be summed up very simply. Both cams should roll over onto the stops at the same time. By adjusting the length of the cables you can do a number of things in the fine tuning and magic department, but what we are concerned about for now, is making sure that the cams are at least hitting the same. There are many ways to check cam timing, but the easiest by far is to have an assistant stand beside you as you draw the bow to see if the cams roll over at the same time. If they are not in synch, you will need a bow press to relax the bow. You will then need to remove the power cable from the cam and either twist or untwist it to adjust the rate at which the cam rolls over. Adjust cam timing if need be, but take note; a little twist goes a long way. An adjustment of as few as 5-10 twists can affect things such as draw length, draw weight, nock adjustment, let-off, etc., etc. Be sure that you don't make huge changes that will effect shooting form later on down the road. This applies to one-cam bows as well.

On a one-cam bow, timing is a bit different, but the theory is the same; maximum performance through optimum cam position. No matter what anyone tries to tell you, the cam on a one-cam bow can be out of its optimal position, or to say it simply, "out of time". Look at the main lobe that comes out of the bottom of the cam and rises straight up towards the idler wheel at the top. If you visualize a line from the string groove along a vertical plane to the idler wheel, the most common position for the cam is to equal that imaginary line. If your cam is not in that position, you may be compromising speed, poundage, let-off, or a number of other important factors. One way to adjust one-cam timing is to twist or untwist the power cable. It should be noted here again, that changes in cable length effect poundage and draw length, among other things. Be careful to not make huge adjustments that will result in poor shooting form.

Take a Rest

Now we will look at the rest. The arrow rest could easily be the single largest culprit in poor performing bows, perhaps even more so than improper arrow selection. I have personally witnessed archers spend as much as $700 on a "top of the line" bow, then put the cheapest $5 rest on it that they can find. The rest is the "heart of the shooting system", if you will. The arrow just flat pit will NOT perform if the rest it is riding on isn't up to the task of quality performance. You wouldn't put bargain barn tires under an Indy car, so why put a cheap rest under your arrow?

For properly setting an arrow rest you will need the bow square from your archery tackle box. On most modern bows, there will be a hole drilled and (most times) tapped into the side of the riser into which the arrows rest attaches. Most call this hole a berger button. After you have set up the bow in your bow vise, (the bow must be plumb for accurate results) visualize a line horizontally across the center of the berger button. The goal for now is to have the centerline of the arrow even with your imaginary line. Fine tuning later will determine if more subtle changes are required. By clipping the bow square on the string at the center serving, you will be able to see easily where the rest and nock point need to be for the beginning setup. Adjust the rest height and nocking point up or down until you achieve this setting. At a later point we will most likely be making subtle changes to these settings, so an entry into the log book noting these would be a good idea here.

Setting center shot is the next step. With the bow still in the vise, and an arrow nocked, find a flat spot on the riser (generally very near the berger button holes) and adjust the tool so that you have the pointer in between the ears of the nock. Flip the tool so the pointer is on the front side of the arrow and adjust the rest left or right until you have both ends matching along the centerline of the arrow. This will ensure that when the arrow is released, it is flying straight from the bow.

Ready, Aim, Fire.

Now we can begin the task of shoot tuning the bow. At this point a paper tuner is highly desired, and can be either purchased at any quality pro shop or from any reputable source. Next, get a bag target or other suitable arrow stopper to place behind the tuner and find a safe spot to shoot.

Next Time:

The art of the paper tune or shooting holes in the news for fun.

Aaron "Cujo" Cooley is a successful archer, bow hunter, and co-owner of Baxter's Specialized Archery, located in Covington, Ga. As well as catering to the bow hunter and target shooter for their equipment needs, Baxter's specializes in custom set up and tuning of target and hunting bows for discriminating archers. If you would like to contact Cujo or Baxter's Specialized Archery, you can call toll free in the U.S. 1-800-BAX-3345 or look them up on the world wide web at http://www.baxtersarchery.com.