How do I know my limbs' draw weight?

The marking on a recurve limb is usually measured at a standard draw length, often 28 inches, so it is a starting point. Your real draw weight depends on your own draw length and the limb bolt settings. The surest way is to measure it at your full draw with a bow scale.

What happens if you dry-fire a bow?

Dry-firing means releasing the string without an arrow on it. The energy that should drive the arrow goes into the limbs, string and cams instead, and it can crack limbs, break the string or damage a compound's cams. Have the bow checked before shooting it again.

Can I use limbs from a different brand?

Often, if the fitting matches. Many recurve and barebow risers and limbs use the ILF fitting, so ILF limbs from different makers usually fit an ILF riser. Bows with their own fitting need matching limbs, and compound limbs are matched to that bow's cams and riser.

Limbs

Limbs are the flexible upper and lower arms of a bow. They store energy as you draw and release it into the arrow. On a recurve or barebow, the limbs set most of the draw weight and are swapped to change it; on a compound they work with the cams, and limb bolts adjust the weight.

Details

Modern target limbs are built in layers, usually a core of wood, foam or carbon between layers of fibreglass or carbon, so they bend smoothly and return to shape shot after shot. Recurve limbs curve away from the archer at the tips, which lets them store more energy for their length than a straight limb.

Recurve limbs are usually marked with a draw weight measured at a standard draw length, often 28 inches. Your actual draw weight depends on your own draw length, so a longer draw is heavier than the marking and a shorter one lighter. ILF limbs come in short, medium and long, and together with the riser length they set the bow's overall length.

On a compound bow the limbs work with the cams, which control the draw force curve and the let-off. Turning the limb bolts changes the draw weight within the bow's range, but never back them out past the maker's limit. World Archery's target rules cap a compound's peak draw weight at 60 pounds.

Both limbs need to work evenly. Tiller, the difference between the upper and lower limb measurements, is set with the limb bolts on a recurve and affects how the bow reacts to the shot. On a compound, cam timing keeps the two limbs and cams working together.

Look after your limbs: many archers store a recurve unstrung, check the limbs for cracks or lifting layers before you shoot, and never dry-fire a bow, which means releasing the string without an arrow. The energy that should go into the arrow goes into the limbs instead and can break them.

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Common questions

How do I know my limbs' draw weight?: The marking on a recurve limb is usually measured at a standard draw length, often 28 inches, so it is a starting point. Your real draw weight depends on your own draw length and the limb bolt settings. The surest way is to measure it at your full draw with a bow scale.
What happens if you dry-fire a bow?: Dry-firing means releasing the string without an arrow on it. The energy that should drive the arrow goes into the limbs, string and cams instead, and it can crack limbs, break the string or damage a compound's cams. Have the bow checked before shooting it again.
Can I use limbs from a different brand?: Often, if the fitting matches. Many recurve and barebow risers and limbs use the ILF fitting, so ILF limbs from different makers usually fit an ILF riser. Bows with their own fitting need matching limbs, and compound limbs are matched to that bow's cams and riser.