Learn How To Adjust Draw Weight On Compound Bows

Understanding Compound Bow Draw Weight Basics

Draw weight refers to the amount of force, measured in pounds, needed to pull the bowstring back to its full draw length. This measurement is fundamental to compound bow operation and performance. Most compound bows range from 40 to 70 pounds of draw weight, though some specialty bows can go higher or lower. The draw weight directly affects arrow velocity, kinetic energy, and ultimately the penetration power of your shots.

The reason draw weight matters comes down to physics and safety. A heavier draw weight means more energy transfers to the arrow, resulting in faster arrow speeds and flatter trajectories. However, a draw weight that's too heavy for your strength and experience can lead to poor form, inconsistent shots, and potential injury. Conversely, a draw weight that's too light may not generate sufficient velocity for hunting larger game or achieving consistent accuracy at distance.

Compound bows differ from traditional recurve or longbows because they use a mechanical advantage system. The cam and pulley system reduces the peak draw weight at full draw by approximately 65 to 80 percent, depending on the bow's letoff setting. This means if your bow is set to 60 pounds with 70 percent letoff, you're only holding back about 18 pounds at full draw, making compound bows more manageable for extended periods compared to traditional bows.

Understanding your current draw weight is the first step before making adjustments. You can find this information in your bow's documentation or by examining the limb bolts, which often have markings indicating the weight range. Many bow shops have tools to measure draw weight precisely, and this baseline information is crucial before attempting any modifications.

Practical Takeaway: Document your bow's current draw weight by checking the manufacturer's documentation or having it measured at a pro shop. This baseline information is essential for making safe and effective adjustments.

Identifying Your Bow's Limb Bolts and Adjustment Mechanism

The limb bolts are the primary mechanism for adjusting draw weight on compound bows. These are typically large bolts located at the top and bottom of the bow's limbs, where the limbs connect to the riser (the central frame of the bow). Most compound bows have either two limb bolts (one on each limb) or four limb bolts (two on each limb), depending on the design. These bolts control the amount of tension placed on the limbs, which directly determines the draw weight.

Each limb bolt usually has marking indicators that show the weight range for that particular bow model. For example, markings might indicate that the bow can be adjusted between 45 and 65 pounds. The bolts typically have numbers or hash marks that correspond to specific draw weight increments, often in 5-pound intervals. Some modern bows use color-coded systems to make identification easier for users who don't have the manual readily available.

To locate and identify your specific limb bolts, first examine the top and bottom of your bow's limbs where they connect to the riser. The bolts will be prominent fasteners that you can grasp with a wrench or Allen key. Take a close look at any etched markings or labels near these bolts. If your bow has four limb bolts, they typically work in pairs—one pair controls the top limb and another pair controls the bottom limb.

Different manufacturers use slightly different adjustment systems. Some bows allow you to adjust each limb independently, while others require equal adjustments on both limbs to maintain bow balance. High-end bows often include detailed adjustment charts in their documentation that specify exactly which bolts to turn and how many rotations correspond to specific weight changes. Many bow manufacturers provide this information on their websites or in user manuals available as PDF downloads.

Practical Takeaway: Locate your bow's limb bolts and note their location, marking system, and any adjustment information available from the manufacturer. Take photographs for future reference when making adjustments.

Tools and Safety Equipment You'll Need

Making draw weight adjustments requires specific tools and safety precautions. The primary tool needed is an Allen wrench (hex key) or wrench that fits your bow's limb bolts. Most compound bows use either 3/8-inch or 1/2-inch wrench sizes, though some use Allen keys. Check your bow's documentation to determine which size you need. Having the correct size tool is important because using an ill-fitting tool can strip the bolt head, making future adjustments impossible or requiring professional repair.

Beyond the wrench, you'll want a draw weight scale or access to one. Digital draw weight scales, which measure the force needed to pull the string, cost between $30 and $150 depending on accuracy. These scales are valuable tools that attach to the bowstring and provide precise measurements as you make adjustments. If you don't own one, many local archery pro shops will measure your draw weight for a small fee, usually $10 to $25. This is often worthwhile before and after making significant adjustments to verify your changes.

Safety equipment is essential. Wear safety glasses during adjustment to protect your eyes from any string tension release. Never adjust draw weight with your bow in a cocking device or with the string drawn back. Always work with your bow in a relaxed, undrawn position. Some archers use a bow press—a mechanical device that removes tension from the limbs—before making adjustments. While not strictly necessary for minor adjustments, a bow press significantly reduces the tension on the limbs and makes the work safer and easier. Bow presses can be purchased for $150 to $400 or rented from archery shops for $10 to $20 per day.

Have a small notepad or use your phone to document your adjustments. Recording the starting weight, the number of turns applied to each bolt, and the resulting weight changes helps you track changes and makes it easier to return to previous settings if needed. Some archers take before-and-after photographs of the bolt positions as well.

Practical Takeaway: Gather the correct-sized wrench or Allen key for your specific bow model, invest in or access to a draw weight scale, wear safety glasses, and keep detailed notes of all adjustments you make.

Step-by-Step Process for Increasing Draw Weight

To increase draw weight, you'll tighten the limb bolts by turning them clockwise. The general rule is that turning each limb bolt one full rotation typically increases draw weight by approximately 2 to 3 pounds, though this varies by bow model. Always refer to your bow's specific documentation for the exact increment per rotation, as some bows may have different ratios.

Start by identifying which limb bolts control which limbs. Most adjustments require turning both the top and bottom bolts equally to maintain the bow's proper alignment and balance. Begin with the top limb bolt. Using your wrench or Allen key, turn it clockwise in quarter-turn increments. After each quarter turn, stop and check that the limb is still properly aligned and not twisting. Then perform the same quarter turn on the corresponding bottom bolt. This alternating approach maintains balanced tension on both limbs.

Only make incremental adjustments—never turn a bolt more than one full rotation at a time without checking your progress. After every half rotation (one quarter turn on top, one quarter turn on bottom), pause and assess the bow's appearance. Look for any signs of limb misalignment, cracks, or stress marks. The limbs should remain symmetrical and not twist or bow unevenly. If you notice any problems, stop immediately and either return to the previous setting or consult a professional.

After completing each full cycle of adjustments (turning both limbs equally), test the draw weight if possible. Either use your own draw weight scale or plan a trip to a pro shop for measurement. Most archers aim to increase weight by 5 to 10 pounds during a single adjustment session, making multiple small changes rather than one large change. This conservative approach prevents over-tightening, maintains equipment safety, and allows you to find your ideal weight precisely.

Keep detailed records of your adjustments. Note the starting weight, how many quarter turns you made on each bolt, and the resulting weight. This documentation becomes invaluable if you need to troubleshoot problems or if you want to return to a previous setting later.

Practical Takeaway: Increase draw weight by tightening both limb bolts equally in small increments (quarter turns), measure after each complete adjustment cycle,