Compound Bow Annual Inspection & Tuning

ContextLay the string flat and work slowly from end to end. A modern compound string is made of 12–20 individual strands twisted together into a bundle. One broken strand reduces the string's rated strength and is a warning sign; two or more broken strands mean retire the string immediately. Look for fuzzing — individual fibers sticking outward — not just outright breaks. Heavy, consistent fuzzing indicates the string has lost its twist structure even if no single strand is severed. Most archery strings should be replaced every one to three years depending on draw weight and shooting volume; replacement runs $60–$150 installed at a pro shop.

ContextServing is the protective thread wrapped around the string at the cam tracks, at the center nocking area, around the peep sight, and at the loop knots. Separation at the cam tracks is the most dangerous failure point — once tracks cut through serving, they will begin cutting the load-bearing string strands underneath. This is a catastrophic failure waiting to happen. Center serving wear shows as visible grooving or flattening where the nock contacts the string repeatedly; a groove you can feel with your thumbnail means the string needs replacement, not just a re-serve. Loose peep serving allows the peep to rotate freely between shots, destroying your sight picture without any other visible sign.

ContextCables transfer the mechanical energy of the cam system and are under extreme tension throughout the draw cycle. Inspect each cable at every point where it contacts a roller, cable slide, or guard — these are the highest-wear locations. Look for flat spots (a squashed cross-section), kinks (a sharp bend that does not spring back), or any strand separation. Also verify that cables are not rubbing directly against limb surfaces, which causes accelerated fraying that is easy to miss until failure. If your bow uses a cable slide, confirm the slide body is not cracked and moves along the cable guard without binding.

ContextBrace height is the perpendicular distance from the deepest point of the grip's pivot to the resting bowstring. Measure with a ruler or bow square and compare to the spec printed in your manual or on the manufacturer's website. A brace height below spec indicates string stretch or a string that is too short; above spec suggests a string that is too long. Both conditions affect arrow speed, noise level, and the bow's forgiveness on a less-than-perfect release. Most bows tolerate a range of ±¼ inch. Correct an out-of-spec brace height by adding twists to the string (raises brace height) or removing them (lowers it), or by replacing the string if it has stretched beyond recoverable range.

ContextOn a two-cam or binary-cam bow, both cams must reach their draw stop simultaneously. Mismatched cam timing causes the bow to have a hard or soft wall on one side, which affects your anchor consistency and places uneven stress on the limbs. The practical field check: slowly draw the bow in a safe direction and observe whether both draw stops contact their respective cables at exactly the same moment. Any visible lead or lag on one side means timing is off. A pro shop with a draw board removes all guesswork from this step. Timing is corrected by adding or removing twists from the specific cable that feeds the lagging cam.

ContextHold each cam firmly and attempt to wiggle it side-to-side on its axle. Any detectable lateral play — even 1/32 inch — indicates a worn bushing or axle that should be replaced before the next shooting session. Cam wobble causes the string to track inconsistently across the cam, which introduces arrow flight variation that no amount of sight adjustment can fix. Spin each cam by hand and feel for grinding, catching, or roughness; debris in the bearing or a damaged bushing produces a notchy feel. Apply a drop of manufacturer-approved cam lubricant to the axle if your model specifies it — many modern bows use sealed or dry bearings that require no lubrication at all.

ContextCams use interchangeable or rotatable modules to set draw length in half-inch increments. Confirm the module is fully seated, that all set screws are torqued down, and that the engraved or marked position matches your draw length. A module that backs out even half a position shortens your actual draw length, moves your anchor point forward, and reduces your back-tension engagement — all without any single change feeling dramatic. While the module is visible, inspect the cam track groove for a shiny wear groove where the string rides. A pronounced groove in an aluminum track means the cam has had significant string contact in a fixed spot and warrants a closer look at string alignment.

ContextA drop-away rest must fall fully and consistently with every shot. Cycle the bow slowly by hand and watch the linkage arm actuate — any hesitation, partial drop, or inconsistency means the linkage cord has worn, stretched, or is catching on a component. Replace the cord before shooting. A whisker biscuit should show no bent or missing bristles at the 3 o'clock or 9 o'clock positions, as those locations guide the arrow through release. For any rest style, grip the rest body and attempt to rotate it on its dovetail or mounting screws. Any give indicates loose hardware — a shifting rest between shots is one of the most common causes of unexplained vertical inconsistency in arrow groups.

ContextGrip the sight housing firmly and apply lateral and vertical pressure — any movement against the riser indicates loose mounting bolts. Tighten all sight hardware to the manufacturer's specified torque, commonly 15–25 in-lb for aluminum risers; use a torque driver rather than guessing. Check the bubble level in the sight housing: a dried, cracked, or completely flat bubble renders the level useless and should be replaced ($5–$20 for a quality replacement level). Inspect each fiber optic pin for broken or kinked fibers — a damaged pin on one yardage is noticeably dimmer than the others in low-light shooting conditions, which creates an inconsistent aiming reference precisely when precision matters most.

ContextAt your full draw anchor, the peep aperture should center naturally in your field of view without any head tilt or string rotation on your part. Have a partner observe you at full draw and confirm the peep is facing squarely toward the target. A peep that requires string torque to align will open inconsistently under field conditions where your grip varies. Check the serving knots that lock the peep in position — they should be tight, with no fraying at the wraps or knot bases. Any free rotation of the peep between shots indicates the knots have loosened; this is best corrected by a pro shop using a peep rotation tool followed by a re-serve.

ContextRun your thumbnail along the entire length of the D-loop material, pressing into it slightly. Flat spots where the release hook has contacted the loop over many shots, fraying at either knot base, or any stiffness or discoloration in the material means it is time to replace it. D-loop material costs under $5 and takes minutes to install, making it one of the cheapest insurance items in archery. While you are in this area, use a bow square to confirm the loop is positioned so your arrow nock sits slightly above level — typically 1/16 to 1/8 inch above center, though your specific bow and arrow combination may call for a slightly different position established during paper tuning.

ContextTorque the stabilizer firmly into the riser's front bushing. Then hold the rod at its far end and attempt to detect any wobble at the riser connection — any play here will introduce vibration harmonics during the shot that no dampener can fully absorb. Rattle the stabilizer and listen for loose internal weight movement; carbon stabilizer rods can have internal weights that shift after a drop, and that rattle will show up in your slow-motion arrow flight footage as a bow oscillation artifact. If you run a side bar or rear bar, check all pivot joints for looseness and confirm that tension adjustment is locked at your desired position.

ContextA bow-mounted quiver that wobbles on its bracket introduces weight asymmetry that affects your point of impact, particularly at distances beyond 30 yards where small torque differences accumulate. Lock the quiver into its mount and confirm there is zero detectable play. Check each arrow gripper individually — bent, compressed, or cracked grippers can damage arrow vanes on insertion or fail to secure broadheads safely. Hood foam that has compressed to less than half its original depth no longer keeps broadhead blades separated from each other or from your arrows' shafts, which is both a damage and a safety concern. Replacement foam hoods are inexpensive and available from most archery retailers.

ContextFor wrist-strap releases, cycle the trigger multiple times and note whether the travel feels consistent, gritty, or has changed since your last session. A gritty trigger usually means debris has entered the mechanism; clean with a release-aid–specific lubricant and work the trigger until it smooths out. Inspect the hook or jaw closely at the point where it contacts the D-loop — a worn groove at that contact point changes the geometry of your release and can cause early or late firing without any conscious change in your trigger pull. For thumb-button releases, confirm the safety engages and disengages cleanly, and that the jaw snaps open and closed with authority. A cracked housing, bent jaw, or trigger that fires outside your intentional pull should ground the release immediately.

ContextHold each carbon arrow by the ends and bend it into a gentle arc while rotating it slowly through 360 degrees. A cracked or splintered arrow produces a faint clicking or crinkling sound and must be destroyed — not just retired to a practice pile. Shooting a cracked carbon shaft can cause it to shatter at the moment of release, driving carbon splinters into your bow hand and forearm. If you are uncertain whether you heard a sound, test again. The cost of a replacement arrow ($8–$25 depending on spine and brand) is trivially small compared to an emergency room visit. Also roll each shaft on a flat surface to check straightness — any visible wobble means the arrow is bent and will fly erratically.

ContextCheck each nock for a crack at the throat — the narrow slot where the string seats. A cracked nock throat can snap at full draw, causing a dry-fire event. Nocks cost pennies individually; replace any with a visible crack. Press each vane at its base to confirm full adhesion to the shaft — a lifting vane at the base will cause the arrow to yaw in flight, scattering groups unpredictably. Check inserts by gripping the field point or broadhead and attempting to rotate it while holding the shaft fixed. Any rotation indicates the insert has separated from the adhesive bond and the arrow is unsafe to shoot until re-glued and fully cured.

ContextShoot five arrows through a chronograph at your standard shooting distance and record the average feet-per-second. Compare this to the baseline you recorded at your previous setup or the start of last season. A drop of more than 10 fps compared to your baseline indicates string stretch, a change in actual draw weight, or a draw length shift — all of which require investigation before hunting or competition. Speed is also the foundation of your fixed-pin sight's yardage calibration: if your bow is now shooting meaningfully faster or slower than when you set your pins, your 40-yard pin may now correspond to a different distance. Most pro shops will chronograph your bow for free or a nominal fee; a personal unit runs $80–$150 and pays for itself quickly.