How To Adjust The Pull Weight On A Compound Bow: A Complete Step-by-Step Guide

Adjusting the draw weight of a compound bow requires making identical, synchronized adjustments to both the upper and lower limb bolts. By rotating these bolts in precise increments, you can safely customize your bow's holding weight and peak draw force to match your physical capabilities. Always consult your manufacturer's specific guidelines to avoid backing the bolts completely out of their pockets, which can result in catastrophic equipment failure.

Pre-Adjustment Inspection and Equipment Checklist

Before altering the tension of your compound bow’s limbs, you must understand the mechanical forces at play. A compound bow stores immense energy. Modifying this system without proper preparation can strip threads, damage limbs, or cause the bow to violently dismantle.

Different manufacturers utilize distinct limb pocket designs, thread pitches, and maximum adjustment tolerances. For instance, highly adjustable "grow-with-you" youth bows may allow up to 12 full limb bolt rotations, whereas high-performance target or hunting bows from brands like Mathews, Hoyt, or Bowtech typically restrict adjustments to between 5 and 10 full turns.

Before starting, clear a clean, well-lit workspace and assemble the following tools and baseline metrics:

Essential Gear and Tool Checklist

• SAE Hex Keys (Allen Wrenches): High-grade steel T-handle hex keys (typically 3/16-inch, 7/32-inch, or 1/4-inch) to match your bow's limb bolts. Avoid cheap, worn-out keys that can strip the bolt heads.
• Digital Handheld Bow Scale: A calibrated scale rated up to 100 pounds to verify exact peak draw weight changes.
• Paint Marker or White-Out: Used to draw a highly visible alignment mark on the bolt head and limb pocket to count rotations accurately.
• Tape Measure or Vernier Caliper: Required to check and measure the tiller height (the distance between the string and the limb base).
• Bow Owner’s Manual: To verify the absolute maximum allowable turns for your specific model.

Mandatory Safety and Technical Standards

• Inspection: Inspect the limbs for hairline cracks, splinters, or delamination. Check the bow string and cables for fraying.
• Locking Screws Check: Verify whether your bow utilizes pocket locking screws on the sides of the riser. Adjusting limb bolts while these are locked will ruin the threads.
• Target Standard: Never draw a modified bow without an arrow nocked, and always point it toward a safe target or use a specialized draw board with a safety release.

Step-by-Step Draw Weight Adjustment Process

Follow these steps carefully to modify your draw weight without compromising the alignment, timing, or safety of your bow.

Step 1: Loosen Limb Pocket Locking Screws

If your compound bow is engineered with limb pocket locking screws, you must disengage them before turning the main limb bolts. These locking screws are typically small socket head cap screws located on the sides or rear of the aluminum limb pockets. Using a matching hex wrench, turn these locking screws counter-clockwise 1 to 2 full rotations. Do not remove them entirely; they only need to be loose enough to free the main limb bolt assemblies.

Warning: Attempting to force the main limb bolts while pocket locks are fully tightened can shear the locking pin, strip the internal aluminum threads of the riser, or permanently damage the limb pivot system.

Step 2: Establish Your Absolute Reference Baseline

To track your adjustments accurately, you must establish a starting baseline. The safest way to do this is to "bottom out" the bow to its maximum factory draw weight. Using the correct size Allen key, insert it into the top limb bolt. Rotate the wrench clockwise until you feel the bolt snug down firmly against the riser. Repeat this step for the bottom limb bolt.

Pro-Tip: Do not over-torque or crank down excessively on the bolts when bottoming them out. Turn them only until they meet firm resistance. Overtightening can crush the delicate polymer limb pocket spacers or damage the limb dampeners.

Once bottomed out, use your paint marker to draw a straight line across the top of the bolt head, extending it onto the surface of the limb pocket. This serves as your "12 o'clock" reference mark, ensuring you can count half and full rotations with absolute precision.

Step 3: Calculate and Execute Symmetric Adjustments

Decide whether you need to increase or decrease your draw weight. Turning the bolts clockwise increases the weight (if they are not already bottomed out), while turning them counter-clockwise decreases the weight.

For safety, work in small, alternating increments. Never turn one limb bolt more than two full rotations before matching the adjustment on the opposing limb bolt. Keeping the limb tension relatively balanced during the process prevents uneven torsional stress on the riser and axle assemblies.

1. To reduce weight, insert your Allen wrench into the top limb bolt and turn it counter-clockwise exactly one full rotation, watching your paint mark return to the 12 o'clock position.
2. Move immediately to the bottom limb bolt and turn it counter-clockwise exactly one full rotation.
3. Repeat this alternating process until you reach your desired weight reduction.

Warning: Never exceed the manufacturer's maximum recommended number of turns out from the bottomed-out position. Doing so can back the bolt entirely out of the riser threaded insert while the bow is under tension, causing an immediate, explosive failure of the limbs.

Step 4: Measure and Balance the Tiller

Once your adjustments are complete, you must verify that the limbs are under equal tension. This is confirmed by measuring the tiller. Using a tape measure or caliper, measure the distance from the point where the top limb meets the riser pocket directly to the bow string at a 90-degree angle. Record this measurement. Next, measure the exact same distance on the bottom limb.

The two measurements should be identical, typically within 1/16 of an inch. If the top tiller is larger than the bottom tiller, tighten the top limb bolt slightly (or loosen the bottom bolt) until they are perfectly balanced. Equal tiller is critical for proper vertical nock travel and clean arrow flight.

Step 5: Secure the System and Verify Weight

If your bow features pocket locking screws, retighten them firmly now to lock your new weight setting in place.

Next, hook your digital bow scale to the D-loop. Smoothly draw the bow back to full draw to read the peak weight. For safety, perform this check using a safe draw board or while pointing the bow at a target with an arrow loaded. Adjusting the weight changes the dynamic spine requirements of your arrow, so write down your new weight to help you select the correct arrow spine later.

Limb Bolt Specifications and Turn-to-Weight Ratios

The relationship between bolt rotation and draw weight reduction varies by manufacturer. The following table provides standard parameters for several major archery brands. Always cross-reference these estimates with your specific bow manual before making adjustments.

Troubleshooting Common Bow Adjustment Pitfalls

Issue 1: High-Pitch Squeaking or Creaking During Adjustment

• Root Cause: Dry, unlubricated limb bolt threads or friction build-up between the steel bolt head and the aluminum washer/pocket bezel.
• Actionable Fix: Press the bow using a certified compound bow press to relieve all string tension. Back the limb bolts completely out of the riser. Clean any grit or old metal shavings from the threads using a brass wire brush. Apply a thin, uniform coating of high-pressure lithium grease or anti-seize compound directly to the bolt threads and the underside of the bolt head before reinstallation.

Issue 2: The Limb Bolt Feels Frozen or Extremely Hard to Turn

• Root Cause: The limb pocket locking screws are still tightened, the steel bolt has suffered galvanic corrosion inside the aluminum riser, or the threads have cross-threaded.
• Actionable Fix: Stop turning immediately to prevent stripping the bolt socket. Verify that all pocket locking screws are backed out. If the bolt remains stuck, apply a small drop of high-quality penetrating oil (such as Kroil or Liquid Wrench) directly to the base of the bolt. Let it sit for 30 minutes, then use a high-leverage, socket-driven hex head wrench to gently break the stiction.

Issue 3: Inconsistent Tiller Measurements After Making Equal Turns

• Root Cause: Unequal limb stiffness (deflection ratings) or slight discrepancies in thread pitch tolerances between the top and bottom riser tapped holes.
• Actionable Fix: Do not worry if the number of turns does not match perfectly. Use your caliper to measure the exact distance from string to limb pocket. Make micro-adjustments (1/8 to 1/4 turn) to only one of the limb bolts until the top and bottom tiller measurements match perfectly. Priority should always be given to matching physical tiller measurements over identical bolt rotations.

Issue 4: Erratic Arrow Flight or Broadhead Tuning Issues After Adjustment

• Root Cause: Significant changes to your draw weight have altered the dynamic spine of your arrow, making it too stiff (if weight was lowered) or too weak (if weight was raised).
• Actionable Fix: Run a paper tuning test to analyze your arrow's flight paths. If you lowered the draw weight, you may need to increase your arrow point weight or switch to a more flexible arrow spine to compensate for the reduced energy output of the limbs.

Frequently Asked Questions

Can I adjust my compound bow's draw weight without using a bow press?

Yes, you can adjust your draw weight using only hand tools and an Allen wrench. A bow press is only required for deep maintenance, such as replacing strings, swapping cams, or removing the limbs and limb bolts completely for deep cleaning and lubrication.

What happens if I back the limb bolts out past the maximum recommended limit?

Exceeding the manufacturer's turn limit will cause the limb bolts to fully disengage from the riser threads. Under the extreme pressure of the compressed limbs, the bow will experience a violent structural failure, throwing components at high speeds and likely causing severe personal injury and destroying the bow.

Will lowering my draw weight change my draw length?

Adjusting your limb bolts does not change the mechanical draw length setting of your cams. However, lowering your draw weight can cause a very slight increase in axle-to-axle length and a minor shift in your peep sight alignment due to changes in string angle at full draw. Always double-check your peep height and sight tape after making substantial adjustments.

How often should I check and lubricate my bow's limb bolts?

Inspect your limb bolts for signs of rust or oxidation before every hunting season or after shooting in wet weather. If you hear squeaking or feel grinding when adjusting the bolts, it is a sign that the threads are dry and require cleaning and lubrication with premium anti-seize or lithium-based grease.

Elevate Your Archery Precision

Perfecting your draw weight is only the first step in maximizing your accuracy and shooting comfort. If you want to take your setup to the next level, visit your local pro shop to have your arrow spine, paper tune, and sight tape professionally matched to your newly adjusted draw weight.