Bow not as fast as you thought?

[Boo]

Danny and I were talking a few nights in a row about strings and brace height and I thought I'd share something. The bow and what arrow is immaterial, but the changes are what I'm sharing.
He took a bow with a starting BH of;
1 1/16" from the string to the riser and got 326 ft/sec

1 3/8" got him 335 ft/sec

1 13/16" got him 338 ft/sec

2 5/16" got him 342 ft/sec

The lesson learned is that if you do not get the speeds you think you should, play with your brace height a bit. Of course with everything else in life, there are diminishing returns. At 2 7/8", he couldn't cock the bow . So don't go crazy with the brace height.

[nchunterkw]

Are the longer brace heights harder on the limbs? I would think they put more stress on them since the limb stays at a higher load at the bottom of the stroke. Not saying it will cause damage or anything...Thoughts?

[wildcatter]

Good info Boo!! But for those thinking this a deal changer????? I wouldn't get to hung up on 15 or 16 fps which is totally meaningless for hunting purposes.

Did Danny say anything about what shot to shot extreme spread, accuracy, shooting noise, vibration and harshness, or anything besides how much less pleasant the bow was to cock?

I played this game with the Matrix and found it not worth the trade off's in real shooting benefits, plus I found from 3/4" to 1 1/4" maybe 3 or 4 fps difference in that series on my 380, not enough to make POI a difference out to 50 yards. I also found my best extreme spread in shot to shot fps was between 1" and 7/8". With that BH my shots stayed within 1 fps for 10 shots. There is so much more about bow performance than speed, that speed is the last thing I think about after I get a new bow in the range I'm looking for,, anything withing 10 or 15 fps of advertised I'm happy,,,,,, if it does everything else I expect!

Here are the differences in a 335 fps speed and a 350 fps speed,, the middle of my sweet spot.
335 zeroed @ 30 yards, it's 6" low @ 40 - at 350 fps zeroed @ 30 yrd.it's 5.52 low @ 40 a whopping 1/2" difference.

335 fps, @ 20 yards it's 2.5" high w/30 yrd zero, 350 fps is .223" high,, wow a whopping 1/4"
then it takes a 335 fps arrow .376 seconds to arrive at 40 yards, while a 350 fps arrow arrives at 40 yards in .360,,,, a whopping 16/100ths of a second faster,,,

I personally would find it rather amusing if anyone were to try and justify this being enough to make a difference they could notice without a chronograph, or expensive measuring equipment to see, let alone make a difference of more than 1 yard out to 40 yards,, but I can assure those that think it matters,,, if it does, you spend way to much time on forums and not enough shooting your bow!!

Just my opinion, is 30 fps is so close in hunting performance out to 40 or 50 yards, that I don't even consider it,, but noise vibration, accuracy, consistency, shot to shot spread, durability, and ease of cocking are all things I consider much more important, than 30 fps at today's bow speeds!

[Boo]

Keith, no question that more bend is harder on the limbs. However, some individuals may be using a low brace height and there's nothing wrong with a bit more brace height on any bow. Lastly, if a 315 might be brought up and past speeds and still not be more harsh than it's 355 counterpart.
Bob, as far as our test last night, he was making them and smacking them on a bow right way, the only numbers we looked at was approx speed relating to BH. I'm sure you know that spread and deviation numbers are irrelevant before the string settles in. Again, we were only looking at the reaction of the bow to BH changes.
Moreover, the people caught up with speed may have an easy solution to their nick picking
The reality is that you're right, 15 ft/sec is of no consequence hunting. But there are more than enough that get indignant about 10 ft/sec. How many times have you heard "I paid for 380 ft/sec" or "they call it a 380". Right or wrong, there will always be a bit of peeing in pants over something that seems consequential to others.
The bow that was being used was a Matrix and the string was a Flemish string.

[sproulman]

This is getting to be like going to College HARVARD ..Great info and I enjoy you experts on here a lot..

[wildcatter]

Bob, as far as our test last night, he was making them and smacking them on a bow right way, the only numbers we looked at was approx speed relating to BH. I'm sure you know that spread and deviation numbers are irrelevant before the string settles in. Again, we were only looking at the reaction of the bow to BH changes.
Moreover, the people caught up with speed may have an easy solution to their nick picking
The reality is that you're right, 15 ft/sec is of no consequence hunting. But there are more than enough that get indignant about 10 ft/sec. How many times have you heard "I paid for 380 ft/sec" or "they call it a 380". Right or wrong, there will always be a bit of peeing in pants over something that seems consequential to others.
The bow that was being used was a Matrix and the string was a Flemish string.

I agree Don, I understand, just like to keep the facts of what chasing speed cost them that think it is something the rest of us already know is irrelevant,, and just how much we are actually giving up that is much more relevant.

The good thing was a great bow and quality string was included in the fun, and a couple top notch archers,,,,,

[Boo]

just how much we are actually giving up that is much more relevant.

Yep, absolutely. Not only that, but this flexibility is just another facet of Excalibur crossbows. Yet another easy way owners can customize their bows!

[Pinpoint]

I find this very interesting! Thanks for posting it Boo!! I wouldn't have thought that BH would have any effect on speed. I don't really chase speed but I like to have an idea of what the bow is shooting. I think a pro chrony is going to be my next purchase.

[Ontario Savage]

Very informative thanks boo

[SEW]

Very informative thanks boo

I agree also. Harshness can come into play at the higher brace heights. I love the feel as the string just lightly goes into the DB killers.

[nchunterkw]

From the data above, the initial 5/16" change gained 10fps. After that a 7/16" change only netted another 3fps and then another 1/2" only got another 3fps. As with all things there is a tradeoff and IMO going above a 1 3/8" BH on this bow is not worth it. But gaining 10fps for 5/16" brace probably is...even for hunting. While it may have minimal effect on accuracy (which is good) it will provide more momentum which is never a bad thing, especially when you are shooting a mechanical head.

[Boo]

From the data above, the initial 5/16" change gained 10fps. After that a 7/16" change only netted another 3fps and then another 1/2" only got another 3fps. As with all things there is a tradeoff and IMO going above a 1 3/8" BH on this bow is not worth it. But gaining 10fps for 5/16" brace probably is...even for hunting. While it may have minimal effect on accuracy (which is good) it will provide more momentum which is never a bad thing, especially when you are shooting a mechanical head.

The variables (arrow weight, limb deflection and draw length) will likely impact the effect of brace height change. So experimentation is key to each individual set up.

[roly]

If you lengthen your brace height, you are shortening your power stroke, wouldn't that cause a loss in speed?

I always thought if you shorten your bh you would gain some speed because you added to your stroke.

[nchunterkw]

From the data above, the initial 5/16" change gained 10fps. After that a 7/16" change only netted another 3fps and then another 1/2" only got another 3fps. As with all things there is a tradeoff and IMO going above a 1 3/8" BH on this bow is not worth it. But gaining 10fps for 5/16" brace probably is...even for hunting. While it may have minimal effect on accuracy (which is good) it will provide more momentum which is never a bad thing, especially when you are shooting a mechanical head.

The variables (arrow weight, limb deflection and draw length) will likely impact the effect of brace height change. So experimentation is key to each individual set up.

Absolutely agree....
Your data reminds me of a good quote I heard once......

"One beer is good. Two beers are twice as good as one. Four beers are not twice as good as two."

[flightattendant100]

From the data above, the initial 5/16" change gained 10fps. After that a 7/16" change only netted another 3fps and then another 1/2" only got another 3fps. As with all things there is a tradeoff and IMO going above a 1 3/8" BH on this bow is not worth it. But gaining 10fps for 5/16" brace probably is...even for hunting. While it may have minimal effect on accuracy (which is good) it will provide more momentum which is never a bad thing, especially when you are shooting a mechanical head.

The variables (arrow weight, limb deflection and draw length) will likely impact the effect of brace height change. So experimentation is key to each individual set up.

Absolutely agree....
Your data reminds me of a good quote I heard once......

"One beer is good. Two beers are twice as good as one. Four beers are not twice as good as two."

Did you and paulsboutform have same math teacher??