# Barebow: additional weight and center of gravity



## ArchAnon (Feb 27, 2018)

Aren’t the weights used primarily for steadying the aiming process, and have little effect on the shot itself?


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## nuts&bolts (Mar 25, 2005)

Hikari said:


> Hi, I am new to archery and am looking to start with barebow with an Olympic ILF riser. Sorry if this is a bit rambling, but I am trying to figure out the mechanism of adding weight and why you would want the center of gravity below the firing line rather than at the firing line.
> 
> It seem most archers have weights under the grip. This seems to be for lowering the center of gravity. However, there seem to be two mounting points, one just under the grip and one near the limb pocket.
> 
> ...




Bernardini Luxor 27-inch barebow riser. Factory drilled holes and factory supplied weights. This riser was designed by Bernardini for barebow shooting.

Your stamina controls how heavy of a riser you can shoot. So, work on your stamina.
The amount of weight, and the position of the weight(s) controls the pendulum effect, how much bottom heavy the riser is. MORE mass, is a more stable shooting platform. Increase the moment of inertia (how difficult it would be to change an object's current rotational speed, which is zero)...then, you increase energy transfer from the bowstring to the arrow.

Think of a cannon. One cannon weighs 10 lbs. Other cannon weighs 2000 lbs. If both cannons try to shoot the same cannon ball, which cannon will have LESS recoil? Same for a barebow riser. HEAVIER riser will be more stable, more forgiving for operator FORM errors, operator mis-alignment.

ILF risers and dedicated barebow risers are very different instruments.
Can you shoot a carbon fiber ILF recurve riser, in barebow competition? Absolutely.
But, the ILF riser is designed to be used with a front stab, an extender, a v-bar, and a top rod.
The barebow riser, with the holes and the factory weights, is designed to be shot barebow, of course.










The Win&Win Inno Max weighs 2.8 lbs, for the riser alone.
The Gillo GT 25 weighs 3.37 lbs, with all of the six available weights in the riser.

"And finally, since the bow hand creates the inertia when the string is released..."
The bow hand does not create inertia, when the string is released.
If your bow hand creates TORQUE...not inertia, when you release the string, then, you need more training for proper bow hand grip technique. I am a recurve coach, and my student just won State Champion for barebow, cadet.

"But it would seem the lower center of gravity would also give the bow addition angular momentum, which would rotate the bow forward around the point of the grip"

No. Look at the holes in the Gillo GT25, a barebow riser. The holes are directly BELOW the pivot point of the grip.
There is no front stabilizer, for barebow archery. The factory weights create a pendulum effect on the barebow riser. We want the barebow riser BOTTOM heavy, on purpose.

Angular momentum happens, when you have an extender, the v-bar on the extender, the long FRONT stab, and a top rod.






The ILF riser with all the stabilizers, is the shooting rig that has forwards angular momentum, quite a bit, again, on purpose.

"Given holding a bow at arm's length places stress on the archer"
No. YOu do not hold a bow at arms length, without ALSO holding the bowstring.
A 3 lb barebow riser is NO problem, for barebow shooters OR ILF Olympic shooters, cuz the bow arm pushes
and the STRING arm pulls, so the arms are in balance, equal and opposite reactions. If you have 20 pounds on the FINGERS (string arm), then, the bow arm is PUSHING away at 20 lbs on the bow hand. The DOWNWARD moment of 3 lbs at the bow hand, with a "torque arm" of say 27-inches from pivot point to the nock groove, gives 81 inch pounds of moment....counter-clockwise moment force.

BUT, you have an opposing moment force. You have 20 POUNDs on the fingers, around the nock.
If we say the nock is 1.5 inches above the pivot point of the grip, we have 30 inch pounds of opposing moment force...clockwise moment force.

So, we end up with a net 50 inch pounds counter-clockwise moment force. This translates to 4 FT lbs, moment force,
from the string hand to the bow hand. This is for a 3 lb riser, and only 20 lbs on the fingers. My barebow champion, a cadet, is 15 years old. 4 ft lbs of torque is no problem. You want the torque force towards the riser. Use a finger sling, to catch the riser, when the riser jumps FORWARDS out of your hand. The forwards JUMP is dependent on the riser design, and riser materials. SOME risers are more {springy}, and other risers have very little forwards jump. Obviously, with more barebow weights on the riser, the forwards jump is reduced. LENGTH of finger sling,
and total riser weight, and WHERE you position the factory weights (which holes you use, and how much weight)
is TUNED during training, for best results.

Barebow risers do NOT have any noticeable angular momentum, again, on purpose.

"It would seem a bow with no weights and a center of gravity around the center less likely to influence the arrow flight."

Nope. Wrong again. You want a barebow riser BOTTOm heavy. A bottom heavy barebow riser is more forgiving of operator error. Seems like you have never shot barebow. TIme to find a barebow coach. Heavy risers will torque less, EVEN if the operator TRIES to torque the riser, due to poor bow hand grip technique. Lightweight risers, with no weight, and not designed by the factory to be bottom heavy, even with zero factory weights, will perform horribly as a barebow riser, cuz a center balanced barebow riser will spin like a six shooter around your "trigger finger".

You want the barebow riser to be bottom heavy, you want a pendulum effect. There are no v-bars in barebow,
so the pendulum effect is what keeps your barebow riser PLUMB, vertical with respect to gravity.

HEAVY means less recoil effect, means more efficient energy transfer from the bowstring to the arrow,
means less wasted energy in riser vibration. HEAVY risers are well damped. Light weight 7000 series risers, without a proper dampening system, will VIBRATE like a tuning fork...which means less energy was transferred to the arrow, and energy was wasted in the riser, cuz the riser is vibrating like mad.

A heavier riser, will change the natural frequency of the riser, so that when you fire the arrow, you do not get anywhere near the natural frequency of the riser. This is why carbon fiber risers are filled with foam, and will have a dampening system somewhere in the riser (usually the limb pockets). Barebow risers (forged aluminum) will not have a vibration problem.


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