Evidence of longbow versus recurve speed at high arrow weights

[pdk25]

If this has been posted elsewhere I apologize.  I have on occasion seen posts alluding to improved performance of longbows with respect to recurves when casting a heavy arrow.  I have been unable to find any objective data to confirm this and wonder if anyone has studies to prove this. Hopefully a study such as this would include bows of different design but similar draw weight that showed increased fps from the recurve with lighter arrows and with increasing arrow weight the longbow would at some point the equal or exceed the recurve speed.

[Orion]

Yep.  I'd like to see it too.

[Bowhunter4life]

My longbows (ACS-CX) are faster than any curve I've shot with heavy or light arrows... and do it quieter too I might add.  I'd also be willing to bet there are quite a few other R/D style longbows that can do the same or at least shoot right with most recurves....

I'm not against recurves, heck I still own one and am planning on buying another shortly.  I've just shot enough different style bows to know what I know to be a fact when I drop the string.

[pdk25]

Bowhunter4life, I understand that they are great bows, but that isn't what I'm looking for.  I'm looking for good evidence of a significant change between an actual longbow and recurve when shooting heavy arrows compared to light arrows.  Truthfully, I suspect that it is primarily folklore.  I'd be just as happy to be proven wrong.

[Plywood Bender-laptop]

Personally, I think its mostly wishful thinking.

Yes, I'm a recurve person, but like to shoot hybrid style bows too.  I think a hybrid is more recurve than LB.

So,to do your test you should a Hill style bow against a highly prestressed recurve (like a Ballistik).  If the theory is true, this test should make it obvious.

Carl

[laddy]

Sam Fadala did a test with a  Wing two wheeler, a Bear takedown, and a Schulz reverse handle.  the longbow was faster than the takedown and I believe faster than the two wheeler with heavy arrows.  different bows will give different results.

[robtattoo]

pdk25, I think it could be a historical hiccup, that's been projected onto modern equipment.

Historically speaking a longbow is a better weapon for projecting a heavy arrow. Compared to a similar era Asiatic recurve, an English longbow is far more efficient at throwing a heavy arrow over long distances (ie; an artillery barrage) 99% due to it's common draw-weights being 80-140# compared to relatively light 40-50# weight of the Asian horsebows.
I'm 99% sure that this is where the (mistaken) belief comes from.

All things being equal (draw-weight/length, arro weight etc...) & taking out the performance extremes such as the ACS CX, the more efficient limb design of the recurve will project the same weight arrow, faster & further than the longbow.

[John Havard]

I have precisely tested more bows of all types than most folks.  I have had to do that in order to understand bow designs and compare specific bows to each other as well as being able to compare types of bows to each other.  Precision in all measurements is an absolute requirement to make meaningful comparisons.  Draw weight to the tenth of a pound at precise draw lengths.  Arrow weights must be precisely the same when measured in grains per pound of draw.  String weight, brace height, even how tightly the nock fits onto the string must be taken into account.  Obviously a shooting machine must also be used since human hands and fingers introduce vast amounts of imprecision into the measurements.

Our website goes into much greater detail, but in summary there are only two primary factors which effect how a bow performs:  1) how much energy per pound of draw the bow stores (SE/PDF); and, 2) how much of that stored energy gets transferred to the arrow when the string is released (dynamic efficiency).

In ALL cases and at every consistent arrow weight (8 grains per pound up to 12 grains per pound) the bow that performs the best at 8 grains per pound will still perform the best at 12 grains per pound.  All bows demonstrate increased dynamic efficiency as arrow weight goes up.  But the old wives tale that certain bows somehow magically gain in dynamic efficiency at a greater rate as arrow weight goes up is simply untrue.  

When you think about it that makes sense.  Energy storage is solely a function of the bow's design and how far it's drawn, so changing arrow weight has no impact on that half of the performance equation.  And based on a heck of a lot of bow tests I can honestly say that I have never seen any bow design increase in dynamic efficiency at a greater rate as arrow weight goes up over any other bow design.

So pdk25, the notion that one type of bow  performs better at lower arrow weights and another type of bow performs incrementally better at higher arrow weights just isn't true.  Pick the bow that provides the best performance at 8 grains per pound and it will still offer the best performance at 12 grains per pound.

[pdk25]

Thank you very much Mr. Havard.  I suspected that was the case.  The only difference that I could see would have been limb weight having an effect, much like impedence matching in a transformer, but I didn't think that that would have an effect over a reasonable weight of arrow.

[Quill Flinger]

I'd like to say thanks too! Cleared up another misconception!

[James Wrenn]

While not on the scale that John has probably tested I have done many bows and agree with him.I too had always heard that about recurves but have never seen it happen.The fastest is always the fastest. jmo

[HATCHCHASER]

Look at the Black Swan website.  The classic limb longbow is slower than the hybrid and recurve at the same poundage at 6 and 9 grains per pound.  Yet  the lb is the same speed as the hybrid and faster than the recurve at 12 grains per pound.  This could only be true in that particular bow.

[ArrowAtomik]

I think it is mainly an old archer's wive's tale.  It may be harder to notice the difference in fps as you go to extreme weight arrows.  If you think about it, one single fps difference between two bows with an (imaginary) 2000 grain arrow is a significant energy difference, but it is hard to see on a chrono.  The same energy difference with a 300 grain arrow will yield a very noticeable fps difference.  Each is still casting with similar energy with either arrow.  It is just much easier to visibly see the difference with a soda straw.  It is hard to see the difference if you shoot a broomstick, but it is there and it is the basically the same in terms of energy.

[mikecc]

This came about with the testing they did with the Black Swan bows. But there a different breed than your standard longbow. I'm with Jon and others the fastest is always the fastest. The slight gain they saw in testing was with stupendously heavy arrows that were unrealistic for general deer hunting. Everyone here likes to think about penetration and using super heavy arrows with 190 grizzlys when if the truth be known 90% of the tradgangers probably just hunt whitetail deer. A 420grn arrow can kill a whitetail as good as a 800grn log making the slight advantage that this topic was about irrevolent.

[George D. Stout]

I think it's an old archer's wife's husband's tale myself 8^).

[laddy]

With the bows I have had, I found that heavy limbed longbows loose less speed with heavy arrows than lighter limbed bows.  However, the slower heavy limbed bows never got faster than the lighter limbed fast bows with the same arrows, there just was not as much change with the slower bow when going heavy on the arrow weight.

[Rob DiStefano]

I dunno about comparing light vs heavy arras shot outta recurves.  From my experience, reflex or mild r/d longbows seem to function best with heavy arras well over 10 GPP.  I have no scientific proof other than my perception of arrow speed and visible arra trajectories out to 20 yards.  

With my current longbows (both are mild r/d Mohawks), the 12+ GPP arras were more stable and accurate than the lighter, faster 10- GPP ones out of the same bows.    

Interestingly, it appeared the almost opposite when testing aggressive r/d hybrid longbows out to 20 yards.  The lighter GPP arras appeared more accurate and flat shooting as compared to a mild r/d longbow, BUT heavier arras in the 12+ GPP range seemed to fly at about the same perceived speed and trajectories as those out of the mild r/d longbows, but with greater "stability" which made for better overall accuracy (for me).  

Maybe all that says something about the transfer of energy from basically reflexed limbs to the heavier arras?  Dunno, don't care - knowing it works is good enuf for me.   :D

[Molson]

I think John is right about the apples to apples science of it all, but sooner or later ya gotta put the bow in your hand.  

I'm with Rob on this one.  Longbows and heavy arrows go together like smoke on pork.

[laddy]

The longbows I have are more accurate with cedars that are ordered heavy for their spine, as well as they are more accurate with the heavier thick walled aluminums versus the lighter thin walled aluminums, same for fiberglass.  What i wonder, since I don't have any to try, are very fast target recurves more accurate with heavier arrows than light as well?  Years ago when the wind came up the FETA shooters broke out the heavy arrows, is that still true today?