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 to 8 arrows, divided into two sets, named Group 1 and Group 2, marked such that you can recognise the two sets, and compare how they group in the target.
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
- Shoot a reference grouping with both of the two sets of arrows:
- Group 1: Pull hard into the wall.
- Group 2: Pull very lightly into the wall, taking care not to be ripped out of the anchor.
- Inspect the arrow grouping:
- If the arrows group together in such a way that you cannot distinguish the grouping of the two sets, you’re done.
- If one set of arrows are consistently higher than the other, you need to adjust the timing of your bow.
- Make a note of the grouping of the arrows, and the timing adjustment.
- Shoot another reference grouping:
- Group 1: Pull hard into the wall.
- Group 2: Pull very lightly into the wall, taking care not to be ripped out of the anchor.
- Inspect the arrow grouping:
- If the two sets of arrows group closer together, your adjustment was correct.
- If the two sets of arrows group further apart, your adjustment was incorrect.
- Adjust your bow accordingly and repeat from step 3 until you cannot distinguish between the grouping of the two sets of arrows.
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 groups, 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.