How Often Should You Replace Your Crossbow Strings?

The Short Version

• Replace every two years: Even if your bow sits in a closet, synthetic string fibers degrade and lose elasticity over 24 months of resting tension.
• Track your shot count: Swap your string every 100 to 200 shots, since extreme pull weights wear down internal threads much faster than traditional bows.
• Watch for physical damage: Retire the string immediately if you see severed strands, heavy fuzz, or gaps in the center serving (the protective thread wrapped tightly around the main string).
• Change cables together: Always replace compound bowstrings and cables at the same time to prevent cam timing errors and dangerous limb strain.

The Standard Replacement Timeline: Calendar Age Versus Shot Count

Crossbow strings do not last forever, even if you rarely hunt or shoot foam targets. String fibers are built from synthetic polymers like high-modulus polyethylene. These fibers stay under constant mechanical strain every day of the year. Even when a bow sits uncocked in a storage case, the limbs hold the string under dozens of pounds of tension. Over 24 months, natural oxidation, room humidity, temperature swings, and steady tension break down the chemical bonds inside the material. A string that is two years old is significantly weaker than when it left the factory, so you should replace it on that calendar schedule regardless of appearance.

Shot count is the second rule for retirement. Crossbows generate tremendous kinetic energy. A standard vertical compound bow might have a pull weight (how much muscular effort it takes to pull the bowstring back) of 60 or 70 pounds. A modern hunting crossbow often features a pull weight between 150 and 220 pounds. Every shot unleashes that enormous force directly through the string fibers, hammering them against the arrow track.

Most manufacturers recommend replacing your string after 100 to 200 shots. Target shooters who practice weekly during the summer can burn through 150 shots in two months. A hunter who only shoots five sighting bolts before opening day might take four seasons to reach that number. Whichever limit you reach first, either two calendar years or 200 shots, marks the safe end of that string. If you use a high-energy rig, such as a crossbow built for hunting in tight spots, keeping an accurate shot log keeps you safe from sudden string failure.

Visual Warning Signs: How to Inspect Your String for Damage

A calendar helps, but physical wear always overrules the calendar. You should inspect your bowstring before every shooting session. Run your fingers along the entire length and look for distinct signs of wear.

Broken or severed fibers: A small amount of light, fuzzy peach fuzz on the outside of the string is normal as wax wears off. You can smooth light fuzz down with fresh wax. But if you see distinct thread ends sticking out, or a frayed clump where fibers have severed, the string is no longer safe. Crossbow strings are bundles of dozens of strands working as a team. When two or three snap, the remaining fibers carry dangerous excess shock, which can cause the string to snap mid-shot.

Serving separation: Serving is the protective thread wrapped tightly around the main string to shield load-bearing fibers from friction. You will find it at the end loops and in the middle where your arrow nock rests. Over dozens of shots, the violent catch of the trigger latch can push these wraps apart. If you see bare core fibers showing through gaps in the center wrap, stop shooting. The metal trigger claw will quickly cut exposed core strands, leading to a sudden failure.

Dry rot and stiffness: A properly maintained string feels smooth, slightly tacky, and bendable. If your string feels like dried paper, looks faded from outdoor sunlight, or feels stiff and brittle when flexed, the fibers have dried out. Dry fibers scrape violently against one another when fired, slicing microscopic strands from the inside out.

Damaged end loops: Check the loops hooked over the limb tips or cam posts. Look for unraveled wrapping, fuzzy patches, or uneven seating. Any distortion at these high-pressure contact points means the string must be replaced immediately.

Strings and Cables: Why Compound Models Need Both Swapped Together

Compound crossbows do not rely on a single string to function. They also use cables (the secondary cords connecting the pulleys on compound bows). These cables crisscross beneath the arrow rail and control how the cams rotate when you cock and fire the bow. They ensure both limbs bend and release at the exact same fraction of a second.

Over hundreds of shots, synthetic fibers experience permanent stretch, often called creep. If you replace only the main string, your new string will have zero stretch, while your old cables remain elongated and worn. This imbalance throws off your cam timing. When cams rotate out of sync, one limb unleashes energy before the other. This causes arrows to fly erratically, lowers arrow speed, and creates severe friction along the barrel rail.

Cables also carry the exact same violent pressure as the main bowstring. They hold the limbs under immense pre-load pressure even while resting uncocked. If an old cable breaks while you aim or shoot, the limbs release instantly, flinging carbon fragments, broken metal pins, and pulleys in every direction. Always purchase a complete matching set that includes the bowstring and both cables, and replace them together.

Routine Maintenance: How Waxing and Proper Storage Prevent Early Failure

Regular maintenance keeps string fibers supple, shields them from moisture, and prevents premature retirement. Follow these simple habits to keep your bow shooting safely for its full two-year lifespan.

Apply quality bow wax to the exposed string fibers every 15 to 25 shots, or whenever the strands feel dry to the touch. Rub the wax block along the bare fibers. Then, pinch the string firmly between your thumb and forefinger and rub back and forth quickly. The heat from your finger friction will melt the wax, drawing it deep into the center of the fiber bundle to coat every strand.

Never apply wax to the center serving where the arrow sits and the trigger latches catch. Wax attracts dirt, sand, and unburnt powder. If sticky wax enters your trigger box, it will gum up the internal trigger latches. That buildup can cause the trigger to drag or even fail to latch properly. Keep wax on the exposed string bundle, and apply a drop of clear liquid rail lube to the flight deck instead.

Store your crossbow in a cool, climate-controlled space. Never leave your bow inside a vehicle trunk or back seat on a hot summer day. Temperatures inside a closed car can climb past 130 degrees Fahrenheit, which melts bow wax right out of the fibers and weakens synthetic threads permanently. Keep your gear away from direct sunlight and damp basements to prevent rot and fiber breakdown.

DIY String Changes Versus a Bow Shop: When You Need a Bow Press

Whether you can change your string at home depends entirely on the design of your crossbow limbs.

Recurve crossbows feature simple curved limbs without wheels or cams. You can usually change recurve strings at home without special machinery. Most recurve models use a simple rope stringer or hand bracket that slips over the limb tips. You draw tension by hand or foot, unhook the old string loops, slip the new string in place, and release tension gently.

Compound crossbows are completely different. Their stiff split limbs sit under hundreds of pounds of pre-loaded pressure. Changing compound rigging requires an archery pro shop bow press (a bench clamp that flexes limbs to remove string tension). A specialized press squeezes the limb tips inward just enough to relieve tension so you can safely unhook the string loops and cable posts.

Never try to press a compound crossbow with ratchet straps, pipe clamps, or woodworking vises. Improvised clamps cannot handle the immense energy stored in crossbow limbs. If an everyday clamp slips, the limbs will whip outward with crushing force, destroying the bow and causing terrible injuries. Modern compact rigs engineered for tight blinds feature narrow limbs under extreme load that require exact press adapters. Unless you own a manufacturer-approved press designed for your specific bow, take your crossbow to a trained technician at a local archery shop to swap the string and cables safely.

FAQs

What happens if a crossbow string snaps while cocked?

When a cocked string breaks, all the stored energy explodes into the bow structure because there is no arrow to absorb the force. This creates an accidental dry fire (releasing the bow string without an arrow loaded). The shock will typically splinter the limbs, warp cam axles, throw sharp parts across the room, and cause serious injuries to your hands, arms, and face.

Can you shoot a crossbow if the serving thread is slightly separated?

You should never shoot a crossbow when the serving thread separates. The center serving (the protective thread wrapped tightly around the main string) keeps the metal trigger claw from cutting directly into the core strands. When wraps separate and bare core fibers show through, the trigger latch can slice the load-bearing threads instantly during the shot.

Does dry firing a crossbow instantly ruin the string?

A dry fire almost always destroys the bowstring and cables even if they look fine at a glance. The sudden violent shock wave stretches synthetic strands far beyond their elastic threshold and snaps internal fibers underneath the protective serving. After any dry fire, stop shooting and have a bow shop inspect the limbs and install a fresh string and cable set before cocking it again.

How do I know if my crossbow needs a new string or just more wax?

If your string fibers merely look dry and show light, fuzzy lint on the surface, applying wax and rubbing it in with your warm fingers will smooth it flat. But if you see cut strands, severed loops, hard and brittle fibers, or gaps exposing the bare core beneath the serving, wax cannot fix it. Those are signs of physical breakdown that require an immediate string replacement.