Bow: Creep Tune

Objective

Perfectly match the timing between the cams to achieve as straight as possible a power stroke in the vertical plain by eliminating bias towards one of the cams. You an almost think of it as the vertical counterpart to a Frech Tune, or a Walk Back Tune, and is a way to perfectly match the cam timing.

Preparation

Place a target with a perfectly level, horizontal line on it at a distance at which you can normally comfortably group arrows withing a 7/8cm diameter, preferably better. Normally 20m or 30m is sufficient, but you can select to further distance if your level of skill allows it.

Make sure you have an accurate sight setting for the chosen distance.

Select 6 or 8 arrows, divided into two sets, marked such that you can recognise the sets. When shooting them, try not to take note which set you’re shooting.

Ensure you have the correct tools available to adjust the timing of the bow. Ensure the bow is within the specifications of the manufacturer.

Technique

  1. Shoot a reference grouping with the first half of the arrows while pulling hard into the wall. Aim at the horizontal line.
  2. Shoot the remaining half of the arrows at the horizontal line, this time just pulling lightly into the wall, taking care not to be ripped out of the anchor point.
  3. Inspect the distances the arrows are from the white line:
      1. If one set of similarly marked arrows are consistently higher than the other, you need to start adjusting the timing on your bow and take note of the adjustment.
    2. If the two sets of arrows are grouped together so well that separate groups are indistinguishable, you’re done.
  4. Shoot another grouping with the first half of the arrows while pulling hard into the wall.
  5. Shoot the rest of the arrows, this time just pulling lightly into the wall, taking care not to be ripper out of the anchor point, but maintaining a bit of pressure on the wall.
  6. Inspect the distances that the arrows are from the line:
    1. If the two sets are grouped are further apart, your previous adjustment was incorrect, and you have to adjust in the opposite direction.
    2. If the two sets are grouped closer together, you’re moving in the correct direction, and additional adjustment in the same direction is required.
    3. If the two sets of arrows are grouped together so well that separate groups are indistinguishable, hopefully on the horizontal line, you’re done, otherwise repeat from Step 6.

Notes

When creep tuning, you’re concerned with the distance between the two sets of arrows and the horizontal line in the vertical. You’re not concerned with left and right grouping at all.

When the timing is very out, you’d observe two very specific lines, each correlating to how much pressure was against the back wall when the arrows were shot.

Be aware changes in your timing will affect both the feel of the bow, as well as the perceived draw weight. The closer your timing is to being perfect, the more solid the back wall of the bow will feel.