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View Full Version : Eliminating bow torque: as requested by Noel


James Park
30-08-2002, 08:37 PM
If you twist the bow counter-clockwise (as seen from above), the arrow will go to the left of centre.
However, with the sight out in front of the bow, twisting the bow counter-clockwise will move the sight pin to the left, and hence when you centre it on the target the bow will be aimed to the right.
So, we have two effects working in the opposite direction and it is posible they could be made to cancel. That is: if the sight extension is the correct length, the amount you aim off to the right can exactly cancel out the effect of the bow torque.
With my sight extension all the way in, I can then shoot a shot with no torque applied to the bow and get a 10 on the indoor range. When I then twist the bow counter-clockwise considerably I can miss the target altogether to the left. Then, with my sight extension about 22cm out in front of the bow I can get the "torqued arrow" in the 10 ring together with the "untorqued arrow". That is, with that sight extension the cancelation is exact.
The beauty is that once I have done this on the indoor range I can then go to 90M, shoot one without torque into the 10 ring, twist the bow a large amount for the next shot and also get it in the 10 ring. That is: once you have cancelled out the torque for one distance it is fixed for them all.
If you have the sight extension too far out it over-corrects. So, you need to experiement a little to find the extension that is best for you.
Just one thing you need to be aware of in doing the testing (no, two things actually):
1. Do not twist the bow so much that the string comes off - very ugly!
2. If you are using a shoot through rest you may find that when you twist the bow you get fletch contact with the launcher and this can give you false results.
Try it out - it really works!!! Never again will you lose points through twisting the bow.

I do have some very good pictures of this in my book "Mastering Compound Bows", available through Marcus.

OldDog
30-08-2002, 08:41 PM
Makes sense to me Jim, thanks for that, I will certainly give it a try, will let you know how I go, cheers

Marcus
31-08-2002, 12:33 AM
I read this report in the Glade a year or so ago Jim and tried on both my Mach 5 and UltraTec. I can confirm that it works as advertised and is a great method for removing left right variations due to hand placement.
It's also covered in detail on Mastering Compound Bows complete with pictures.

cajunitaly
04-09-2002, 07:00 AM
I want that book marcus!!!!

8)

mike
04-09-2002, 11:58 AM
Jim, have yo ever made a study of the relationship between the sight extension length and the brace height (or any other measurement) to see where this length comes from (going on the assumption that for a given bow the optimum extension will be the same for every archer).

Reason I ask is that 22cm is close to the brace height of your bow I beleive.

James Park
04-09-2002, 05:35 PM
Mike,
I have given quite a deal of thought on how to analyse the torque cancellation. It is quite a complex system to analyse, and I have quite a way to go, I think. It gets back to things like the torsional rigidity of the bow and the dynamics of the string's return to the rest position. Consequently, most of my work has so far been experimental.

James Park
04-09-2002, 06:21 PM
For those of you who subscribe to Archery Focus: The September/October 2002 issue includes an article I have written on eliminating the effects of bow torque.

cajunitaly
06-09-2002, 07:50 AM
not that i really know anything, but the pat 2 days, i been adjusting my rest and/or sights, right and left, to reduce what i take you are talking about (bow torque) out. being at the level im at it seem everytime i grip the bow its either a strong grip or soft grip. it feels the same but ussually out of 5 shots @ 20m i will ony get 2/3 arrows slammed together in a <3" group. the others my be right or left 3 to 5"'s of center. Is that something i will resovle over time of shooting, or is (bow torque) gonna be keeping me from slamming 5 together in a 3" group? I dont shoot a hoyt, or a mathews, or any other high end bow, I have a G2 that is light , very fast and shoots extremely flat. im shooting carbon express arrows. which i know arent the greatest, but they seem to shoot well. IS THAT A FACTOR? If you guys wanna know that the G2 is capable of here is a little article i found a couple weeks ago.

http://archeryworld.com/bows/testtune/g2.nmpl