Page 1 of 1

Three Different Limb Profiles.

Posted: Sat Nov 11, 2023 4:32 pm
by greybeard
The three bows tested were marked 30# @ 28” AMO.

Un-braced limb profiles;
*
1 A T M Bow Profiles.jpg
1 A T M Bow Profiles.jpg (107.34 KiB) Viewed 2978 times
*
Assyrian bow weighed in at 30.86 lbs. with a stored energy of 392.86 inch lbs.
Turk style bow weighed in at 30.46 lbs. with a stored energy of 368.48 inch lbs.
Mandarin Duck recurve weighed in at 31.52 lbs. with a stored energy of 358.67 inch lbs.

The handles of the bows at the pivot point were slightly over one inch deep so the bows were drawn to 27” DLPP on the shooting machine. For consistency a modified release aid was used to loose the arrows.

Stored energy results for the bows tell a different story, although the Mandarin Duck had the highest draw weight it achieved the lowest stored energy reading.
*
2 Stored Energy Compilation.jpg
2 Stored Energy Compilation.jpg (146.27 KiB) Viewed 2978 times
*
The F/D graph illustrates the rate of increase of stored energy during the draw cycle. As you can see the highly curved limbs of the Assyrian bow build up energy in the early stages of the draw cycle. The Assyrian bow also has a slightly longer power stroke.
*
3 F D Curve Compilation.jpg
3 F D Curve Compilation.jpg (83.89 KiB) Viewed 2978 times
*
Arrows used in the test were 600 spine carbons with 100grain field points and 3 x 4 inch shield cut feathers with an all up mass of 302.7 grains.

When looking at the chronograph results the bows showed an efficiency result around 87.5 %.
*
4 Predicted Velocity Compilation.jpg
4 Predicted Velocity Compilation.jpg (106.21 KiB) Viewed 2978 times
*
As with most Asiatic static tip bows, the profile of the Turk style bow needs to be drawn to at least 30 to 32 inches to take full advantage of its design.

Daryl.

[Performance is only a part of the equation; use the bow that gives you the most enjoyment.]

Re: Three Different Limb Profiles.

Posted: Mon Nov 13, 2023 6:22 am
by Stickbow Hunter
Good comparison. One can see why the Assyrian bow has such good performance.

Jeff

Re: Three Different Limb Profiles.

Posted: Wed Nov 15, 2023 5:06 pm
by greybeard
Jeff,
The Assyrian is an amazing little bow.

All up weight is about 600 grams or 22ozs. The handle is almost non existent yet the bow feels good in the hand when an arrow is loosed, perhaps this is because I use a relaxed grip.
*
Assyrian Braced.jpg
Assyrian Braced.jpg (10.66 KiB) Viewed 2840 times
*
My only criticism of the bow is that the circumference of the handle is a little small and I had to wrap some suede around it.

Daryl.

Re: Three Different Limb Profiles.

Posted: Fri Nov 17, 2023 9:26 am
by Stickbow Hunter
It looks good strung too. I would prefer a thicker handle section also.

Jeff