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How do you control or modify hand shock in an otherwise efficient bow

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Woodbear:
Hand shock.
What do you bowyers do in the design of a bow, or modifications to the bow during tillering to minimize or adjust the hand shock?

Here is a little background to this question.

I am making a 6 foot long red oak bow with a target of about 35# at 30” of draw. The design is a working handle pyramid style bow, 1.5inch wide at the widest point in the limb at 9inch from the center of the bow. The handle is narrowed to 1 inch wide and 0.75” thick. Limb thickness is about 0.50” (at 9in from center) the tapering sightly to 0.40” at the tips. The bow currently draws 33# at 28”, has no set in the central +/-9” and gentle set in both arms (beyond 9”) of just under 1 inch.
With my release style (two split finger), I am getting 153fps with 353 grain arrows at 28” draw, so the bow is delivering 61% efficiency which is comparable to many of my best bows.

The reason for the question: With this bow I feel the hand shock as a vibration persisting for several cycles lasting for about ½ second. The hand shock is not severe, but it is the obvious vibratory feel that I find annoying. With my other bows there is a similar amount of total hand shock, but the character is more of a muffled “thump” than a vibration.

So, what do you bowyers do with hand shock?
Do you have a specific favorite design that has favorable hand shock?
Should I ignore it as the bow is delivering good speed & efficiency?
Pad the handle to muffle the vibration?
Re-tiller to a lower weight?
Start over with a design that has a larger rigid handle?

Dave

Eric Krewson:
Hand shock is usually caused by the limbs being out of time, in your tiler picture the right limb is stiff in the fade and appears stronger than the left limb.

You could shoot a heavier arrow, that would dampen the hand shock.

TimBo:
You could also try flipping it over.  Are you drawing the string with just two fingers?  I suppose if that is the case, it might not make as much of a difference as one over/two under.  Maybe try that anyway, try heavier arrows, and take a few careful scrapes on the stiff fade Eric mentions if the first two things don't help.  Maybe even use sandpaper so as not to remove too much material.  I have also had luck changing where I grip the bow slightly (if the RH limb is top, I would slide down just a wee bit and evaluate).  What kind of string are you using? 

superdav95:

--- Quote from: TimBo on August 26, 2024, 11:22:32 am ---You could also try flipping it over.  Are you drawing the string with just two fingers?  I suppose if that is the case, it might not make as much of a difference as one over/two under.  Maybe try that anyway, try heavier arrows, and take a few careful scrapes on the stiff fade Eric mentions if the first two things don't help.  Maybe even use sandpaper so as not to remove too much material.  I have also had luck changing where I grip the bow slightly (if the RH limb is top, I would slide down just a wee bit and evaluate).  What kind of string are you using?

--- End quote ---

Agreed with Eric and timbo.  I was also wondering what string material as my next question.  Also consider having someone take a video in slow mo mode from the side as you come to full draw and release.  You may just be able to see the timing issue Eric was speaking of.   

sleek:
I once made an extreme lever/recurve that would shoot the string off. I went heavy in the arrows and it calmed down and became a rather good shooting bow. I have noticed a few things cause hand shock, the obvious mass distribution, timing, and also limb twist only enough. If the limb has any sideways bend it will torque the limb on the draw and that's energy that can't go into the arrow. I have also noticed if I make the bow really long with a low draw I tend to get shock. Probably a mass distribution thing again.

It's great to see you on here Dave hope you have been well.

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