Compound bow tuning. Frustrating to some, a favorite hobby of others. Over the years, tuning and archery tech have become the most enjoyable part of archery to me throughout the winter months after the previous season has passed. Over time, as I have learned more each year, I have developed a systematic tuning approach to make sure that my equipment is properly set up for the upcoming season.
I’m not the guy who buys a new bow every year. Instead I prefer to shoot a bow for about 5 years. This allows me to learn the bow, how it works, and how to best tune it. My current bow for sake of my process below, is a 2017 Hoyt Pro Defiant 34. It has the 2.1 cams set at 28” of draw length, and it is pulling 80.6# according to my scale. My current arrow setup is a 4mm Easton carbon injexion cut to 27” and with 100 grain deep six points. This yields an arrow a little over 450 grains that shoots through the chrono at 291 FPS.
Why Tune Your Bow Yourself?
Before I walk you through how I tune, I want to address a couple things. First, why should you tune your bow yourself? After all there are a lot of pro shops that can tune very well, better than me in cases I’m sure. However, unless they are tuning that bow while it is shot from your hand, the bow most likely won’t shoot the same for you. If you’re dropping a bow off to get tuned and Picking it up later, it most likey won’t shoot perfect when you pick it up.
Secondly, the attention to detail. At best most shops will paper tune your bow. As I will describe below, paper tuning is my rough starting point. It lets me know that I’m close. However, you can make a lot of adjustments without a paper tear changing on a fletched shaft.
For these two reasons I have found it both more practical and more effective to do my own bow setup and tuning. I take a lot of pride in knowing that no one else has been responsible for touching any part of my bow. I also feel that since I began doing this tuning process myself, I have gotten much better results in terms of down range accuracy.
The biggest downside to doing your own work on a compound bow is the investment in the equipment. There is no way to do this well and in a safe manner for the bow without a quality bowpress. In addition to that an arrow saw, bow vise, serving, pliers, levels, etc are all things that are necessary or very close to mandatory.
The big one for most people I’m assuming will be the bow press. For me personally, it has been one of the best investments I’ve made, and it has allowed my shooting and accuracy to move to an entirely different level. So, if you are serious about getting your archery equipment absolutely perfect, I can’t help but to recommend buying a good quality bow press.
Make sure to check and see which bow presses are approved by the manufacturer of your bow. Many of the good ones work almost universally with various bows, but some times there may be an extra adapter or bracket to ensure that you don’t do damage to your bow limbs.
This where everything starts for me. A bad string is a bad foundation to build everything else. A great bowstring is an absolute must for consistency. Personally I will take stability and consistency any day over speed from a string.
When it comes to a string there are a few things to decide on. First being the string material, second being the serving material. After that I suppose colors come into play. While no one wants an ugly looking string, the looks are far behind the importance of the first two factors I mentioned.
Once I have my string and cable set picked out and in hand, I go ahead and install it, and get the timing roughly set on the cams. I don’t care if it’s perfect, I just want it to be somewhat even so I can shoot 40-60 arrows through the bow.
Typically I do this at 5 yards or so and just pound them into a target. It can be a good time to work on some form with a hinge release, or you can just power through the process. The point here is to get the string settled in to where it will stay on the bow for the rest of its life.
I’m going to leave the setup out of this post for now, and possibly address it later. However, after my string is installed this is where I would tie in my peep at the correct height, serve my mocking points, tie my d-loop and level the 2nd and 3rd axis of my sight. There are several great videos on YouTube if you need to learn how to tie any of these setups into place on a string.
Timing and Center Shot
After the string is settled I go back to the press first and set the timing of the cams. This just means that I am making sure that the draw stops on my bow hit the cables at the exact same time. This is done with either a draw board or a hanging hook, and then drawing the bow back and watching for when the draw stops contact in comparison to each other.
While doing this I will also check the poundage of the bow. If it is under peak weight spec, I will add twists to the cables to bring the weight up, and if it is over, I will take twists out of my cables as I adjust the timing. If the poundage is close I may choose to add twists to make adjustments or add from one end and take from the other.
Being careful to only make full twists in the cable ends helps avoid serving separation. Never make a half twist in a cable the attaches to the cam of the bow, as it will force the memory the serving is holding into the opposite direction. This will often cause your served ends to separate and fall apart.
After I have set my timing, I will then set my rest using the arrow that I will be shooting. I set the rest to hold the arrow perfectly level, and exactly at the centershot that the manufacturer recommends. This is my zero point, and ideally exactly where I want the rest to remain if possible.
Paper Tuning: Coarse Adjustment
Now I will grab a couple arrows and something that will allow me to shoot through paper. There are a lot of ways to build something to paper tune with, but if you’re in a pinch just cut a square hole out of a cardboard box and tape some paper over it. This works just fine.
I try to keep the front of my bow about 6 feet from the target while paper tuning. I will then shoot two or three arrows through the paper and analyze the tear. There are great pieces of literature on what each paper tear means, so instead of me re-inventing the wheel, you can do some more digging to figure out how to correct tears with your bow.
Depending on your paper tear, and what type of bow you have will dictate where you go from here. This step alone is why I am also not much of a fan of certain bow brands. Not because they don’t work, but rather because I don’t like to tune them. With a hoyt, I will fix my paper tear by yolk tuning.
I will take 1/2 twist out of one side of the split cable, and add 1/2 twist into the other. For a right handed shooter, if the tear is nock left, I add 1/2 twist to the left cable and remove from the right. For a nock right tear, I would do the opposite. Adding and removing equal twists will keep the cam timing relatively unchanged during this process.
After I have done that on the bowpress, I shoot again.
If after an adjustment the tear goes from one side to the other, say nock left to later nock right, then the adjustment has gone too far. If the adjustment was only 1/2 a twist in total, then I will go back to the previous adjustment, and then instead microadjust the rest a slight amount.
Lastly, if I have nock high or low tears during this, I will only address them before my left/right tear is corrected. If there is a problem, which there usually isn't if the arrow is set level, then I will adjust the height of the rest by 1/32” at a time either up for a nock low, or down for a nock high.
Bareshaft Tuning: Fine Adjustment
Now that I have a good paper tear with fletches, I move on to a bareshaft. To do this I start at 20 yards with 1 bareshaft and 1 fletched shaft. I will shoot them both and note the impact points. I will repeat this about 3 times.
The bareshaft will not correct itself after leaving the bow, so the goal here is to have the arrows as close together as possible. For me, I like to see them touching at 20 yards, or at least under 1” apart.
It is worth noting here though that if you can’t shoot 1” groups consistently at 20 yards with two fletched shafts, that you probably don’t have the form needed to bareshaft tune.
If the arrow impact a bit apart, I will now use the rest to fix these differences. With a good paper tune, the difference at 20 yards to start with shouldn’t be much more than a couple inches. Starting again with horizontal spread, I will move the rest to the right if the bareshaft impacts left, and opposite if it impacts right.
For vertical spreads I will also move the rest in the direction I want the bareshaft to move. So if the bareshaft is low I will move the rest up and vice versa if it is high in comparison to the fletched arrow.
These adjustments are very small, and also why I would suggest that anyone buying a new rest should get one that is micro-adjustable. Being able to make a 1/64th inch adjustment here in a planned direction is very nice. Repeat this process until the shafts contact less than an inch apart for several groups in a row.
Lastly to finalize my bareshaft tuning, I will go back to the paper and shoot a bareshaft through it at 6’. The hole should be perfect if the rest of the bareshaft tuning was done correctly. If it isn’t perfect, I will typically go back to shooting at 20 yards, or maybe extend to 30 yards to refine what I’m looking at a bit more. It is difficult for me to tell the nock end from the point end on a bareshaft paper tear, so I prefer to do it by shooting groups as described above.
Once this is done, my bow is fully tuned and now just needs sighted in. I’ve played with this in the past, and if my bareshafts will shoot a bullet hole through paper, they will also group with a fletched shaft out to 80+ yards.
Tuning a bow isn't nearly as hard or complicated as it is made out to be. With the right tools, and a little bit of practice you can have confidence to perform any task your bow may need.