What is tiller in archery?
Tiller in archery usually means the difference between the upper and lower limb-to-string measurements on a strung bow at rest. Positive tiller means the upper distance is larger. On an adjustable recurve, limb-bolt settings change that relationship; on a fixed-limb bow, the bow maker, or bowyer, establishes much of it during construction.
How do you measure tiller?
Measure with the bow strung and resting, without drawing it. Use a bow square or ruler at the manufacturer's specified upper and lower reference points, commonly near the limb butts where they meet the riser. The measuring points must be comparable.
- Check that the limbs are fully seated and the string is correctly in place. Confirm the brace height before taking comparison measurements.
- Measure squarely from the string to the upper reference point, then repeat at the lower one. Keep the ruler angle consistent.
- Subtract the lower measurement from the upper measurement. Write down both measurements as well as their difference.
For example, an upper distance of 7 inches [177.8 mm] and a lower distance of 6 7/8 inches [174.6 mm] give positive tiller of 1/8 inch [about 3.2 mm]. Those numbers illustrate the subtraction; they are not a setup recommendation.
What do positive, zero, and negative mean?
| Tiller | Relationship |
|---|---|
| Positive | Upper limb-to-string distance is greater than lower. |
| Zero | Upper and lower distances are equal. |
| Negative | Upper limb-to-string distance is smaller than lower. |
Your bow hand pushes at the grip while your fingers pull the string near the nock. Those forces act at different heights. Tiller adjustment changes the limb relationship to suit that loading. A small positive setting is a common starting point for split-finger recurve shooting, while three-under and string-walking setups may need a different starting point. Follow the equipment maker's guidance first.
Matching a measurement does not guarantee that the bow will feel settled at full draw. Finger pressure, grip pressure, and string walking also affect the load. There is no single tiller number that suits every archer and bow.
How should you approach an adjustment?
Use the manual for your exact riser. Confirm the safe limb-bolt range and the required procedure for loosening locks, unstringing, and securing the bolts. Never back a bolt beyond its permitted limit. If the instructions or previous settings are unknown, have a qualified shop establish a safe starting setup.
Record the original settings and make a small, measured adjustment within the manual's limits. Recheck tiller, brace height, and draw weight afterward. Keep the arrows and shooting distance unchanged while assessing the result.
When should you leave tiller alone?
One noisy shot or one vertical group does not identify a tiller problem. Inspect limb seating, loose fittings, and arrow clearance, and check that your hook and grip are repeatable. Change one setting at a time so you can tell which adjustment affected the shot.
On a one-piece longbow, adjusting the limb bend can involve removing material. That is bowyer work and can permanently weaken the bow. Do not sand a limb to copy an adjustable recurve's tiller measurement.
Questions
Is tiller the same as brace height?
No. Brace height is a single distance from the string to the grip's reference point on the braced bow. Tiller compares two limb-to-string distances, one upper and one lower. Both describe the setup, and changing limb-bolt settings can affect other measurements, so recheck them after an adjustment.
Does zero tiller mean the limbs are identical?
Zero tiller only means the measured upper and lower distances are equal at the chosen reference points. It does not prove identical limb stiffness or equal behavior during release. Limbs can have built-in differences, and your grip, finger position, and draw affect how you load the assembled bow.
Should you use negative tiller for barebow?
Some barebow setups use negative tiller, but it is not a requirement for every bow or crawl. Start within the manufacturer's recommended range and work with a coach familiar with your equipment. Compare repeatable groups and bow behavior across the crawls you use before deciding that a different setting helps.