Tillering in Archery is the process of shaping the limbs of a bow so they bend evenly and work together. While it is a critical step in building a wooden bow from scratch, archers also use the term to describe balancing the tension on a modern compound or recurve bow.
How Tillering Works in Bow Building
When a bowyer starts with a piece of wood, the “limbs” (the arms of the bow) are often stiff or uneven.
- Removing Material: The bowyer carefully shaves thin layers of wood off the belly of the limbs.
- Checking the Curve: They place the bow on a tillering tree—a frame that allows them to pull the string from a distance—to see how the limbs curve.
- Balancing the Bend: If one limb is stiffer than the other, or if a specific spot doesn’t bend enough, the bowyer removes more wood from that area.
The goal is a perfect, symmetrical curve that distributes the mechanical stress evenly so the bow doesn’t snap.
Tillering on Modern Bows
On modern compound or recurve bows, you don’t shave off material. Instead, you adjust the tiller height.
- Measuring: You measure the distance from the string to the point where the limb meets the riser (the handle).
- Adjusting Bolts: You turn the limb bolts to increase or decrease the tension on each limb.
- The Goal: Usually, the bottom limb is slightly stiffer (a shorter tiller measurement) than the top limb. This compensates for the fact that your hand grips the bow below the actual center point.
Why It Is Important
Proper tillering ensures the bow performs at its peak. If your tiller is off:
- The Bow Vibrates: You will feel extra “hand shock” or buzzing after the shot.
- Poor Aim: The bow may want to “tilt” up or down in your hand while you aim.
- Noise: An unbalanced bow is often much louder when it fires.