Discussion Question #1 Brace Height

[nchunterkw]

Been noticing many new members as of late, and thought about having a "tutorial" of sorts via different "Discussion Questions". Here's number 1.

How do you determine the "optimal" brace height for a given bow (step by step), and what constitutes "optimal" to you? Further, why is maintaining the proper BH important?

Fire away

[vixenmaster]

Is there an actual optimal brace height fer everyone. There are settin's that fall into thats around the sweet spot. Example my 355 has Buggy bumpers n i like my string right at a 1/4" off of them. Where as my 405 wid the REDS i like it 3/16" off due to the fact the REDS have a larger surface to spread the impact of the string

[paulaboutform]

I think if you were to put the time in and test different brace heights every 1/16" -1/32" you would find the spot that suits you best in terms of perceived sound. I maintain that once you find that spot it's imperative to maintain that exact brace height to achieve pinpoint accuracy. I'm not talking about hunting accuracy but rather target accuracy. I can watch my poi change with a 1/6" difference in brace height at extended ranges.....I keep a 3/4" B.H. on my M380 and have a felt pen mark on the side of my rail that my string just touches to keep constant.

Paul

[crp]

I can pretty well shoot 1 hole groups at 25 yards (off a rest) with my 355 with a 5/8" brace height. I tried 3/4" and groups opened up to 2".

[nchunterkw]

I can pretty well shoot 1 hole groups at 25 yards (off a rest) with my 355 with a 5/8" brace height. I tried 3/4" and groups opened up to 2".

Wow. That seems a little out of the norm to me, especially off a bench at 25yds and for only a 1/8" change. Many times in the summer I can see that much change in 1 session and only see a POI shift. The groups never open up though. This would be with a Vortex.

What arrows?

[crp]

I can pretty well shoot 1 hole groups at 25 yards (off a rest) with my 355 with a 5/8" brace height. I tried 3/4" and groups opened up to 2".

Wow. That seems a little out of the norm to me, especially off a bench at 25yds and for only a 1/8" change. Many times in the summer I can see that much change in 1 session and only see a POI shift. The groups never open up though. This would be with a Vortex.

What arrows?

17" BEE's with 100 grain Shuttle T broadheads, total weight is 409 grains

[nchunterkw]

Those seem fine to me. I just don't understand the 1/8" BH difference causing a 2" group change at 25yds.

Anybody else have a thought?

[Kegbelly]

Those seem fine to me. I just don't understand the 1/8" BH difference causing a 2" group change at 25yds.

Anybody else have a thought?

I would agree with Keith, I can't see groups opening up that much caused by a 1/8 inch change in brace height. I did some string tests last year for a couple people on the forum and I put hundreds and hundreds of shots spread across many different strings, shooting the same strings from as high as 7/8" brace height down to zero (touching REDS) as the strings settled in and the biggest change I saw was a couple feet per second drop and more sound/shock as brace height dropped on a given string. There may have been a slight change in POI as brace height changed, but certainly not a 2" spread from a 1/8" change. Just my observations....

[Masboy]

With older bows vixen-nox I just keep it above the low line an sometimes higher than the high line an never found a sweet spot. Could tell no difference in accuracy long as i kept it the same place . small changes in height if the brace height is not kept the same place . lots of accuracy testing out to 80yds.

[8ptbuk]

I see hardly any change in speed or POI at normal hunting ranges . I keep mine set at 3/4 BH normally and use a mark on the side of the Rail for a quick reference . Mike

[Normous]

Agreed, during my Max/Nox/Votrex shooting years I studied the brace height architecture and its relationship that has been in place on the faster Excalibur long limb run using custom strings. My effort was to determine if an opportunity existed to improve performance over the factory string offerings and I posted my results.

In short, I also found that in most cases less than 5 fps or less can be verified between acceptable high and low brace heights and not once do I remember distinguishable variations in group sizes between the upper and lower acceptable brace heights.

[crp]

Those seem fine to me. I just don't understand the 1/8" BH difference causing a 2" group change at 25yds.

Anybody else have a thought?

I would agree with Keith, I can't see groups opening up that much caused by a 1/8 inch change in brace height. I did some string tests last year for a couple people on the forum and I put hundreds and hundreds of shots spread across many different strings, shooting the same strings from as high as 7/8" brace height down to zero (touching REDS) as the strings settled in and the biggest change I saw was a couple feet per second drop and more sound/shock as brace height dropped on a given string. There may have been a slight change in POI as brace height changed, but certainly not a 2" spread from a 1/8" change. Just my observations....

Yeah, it didn't seem right to me either. I only test with broadheads and I started out with the 3/4 brace height. I would shoot 1 arrow into my 18/1 and mark the hole with a small twig. I shot a few 3 shot groups and none of the holes would be touching but noticed the last group was better then the first. My string had stretched a little so I set the brace height at exactly 5/8 and bingo, pretty much 1 hole groups.