Limbs Limb construction vs Draw weight

lihp

New member
Whilst I understand that better limb constructions are a smoother dress, less susceptible to temperature changes, don't stack as much or as soon, and are usually more efficient.

How much difference can it make?

If you have a standard 30lb set of beginner limbs with a generic fibreglass with wooden core construction, and compared them directly with a 30lb set of higher end, Carbon and foam core limbs. How much extra range do you get? How much more draw weight with the cheaper limbs, do you need to match the extra range, or arrow speed given by the higher end limbs of the same draw weight?
 

Timid Toad

Moderator
Staff member
Supporter
Fonz Awardee
Ironman
Lots of reasons, but none you could put figures to.
Fibreglass is heavy, which slows them up. Carbon is lighter and stronger. But require different techniques (like curing) for assembly. Cheaper limbs can be susceptible to heat and cold. Cheap limbs you are restricted on the string materials you can use. Dacron is slow and stretchy. They might be adversely affected by rain. Better limbs may have a different profile which is expensive to hand build. But they'll be a lot faster. More expensively built limbs will likely be more reliable. Faster limbs will require a higher spined arrow than the equivalent cheap limb.
But putting figures to it? That will depend very much on you, and how you shoot.
 

Mark31121

Member
Ironman
I can give a little info between some top end limbs - Hoyt G3's with 44-46 lbs on the fingers and Hex 6 BB2 40 lb on the fingers and I get better sight marks off the Hex's despite the lower poundage (numbers are tricky, my sight mark for 50m on the G3's was the same as 30m for the hex's). This is with everything else being the same, even down to the string material.

When I swapped from some basic Samicks to the G3's there was seemingly an improvement on cast with a similar poundage (same arrows), but it was also a different riser and it was quite a while ago so numbers are tricky.
 
D

Deleted member 7654

Guest
Simply too many variables to "understand"...
I don't s'pose even the maufacturers would claim to fully understand all the geometry and variables, without resorting to experiment.
Del
 

lihp

New member
I'm surprised it's test that hasnt been done.

Same length riser. Same length limbs. Same weight limbs. Same draw length and then just change the limbs through a manufacturers range.
 

Timid Toad

Moderator
Staff member
Supporter
Fonz Awardee
Ironman
What would be the point? In real life conditions things change. Arrow weight requirements would change through the test. Individual archers' styles make differences. Even arrow charts are clearly labelled as a guide. No manufacturer is going to say "these limbs don't like rain or cold, and are slow"
Too complicated, too many variables, no benefit to either archers or manufacturers. *Generally speaking* you get what you pay for.
 

lihp

New member
So there's no empirical data to suggest that a ?400 limb provides a faster arrow speed than a ?60 set of limbs?

The only information is based on manufacturers sayin "faster"?
 

Timid Toad

Moderator
Staff member
Supporter
Fonz Awardee
Ironman
A bit better than "sayin "faster" ".
And it's not just about faster, it's about longevity, consistency and stability. If you're happy with a ?60 limb, and you can't tell the difference, then good for you.
 

lihp

New member
A bit better than "sayin "faster" ".
And it's not just about faster, it's about longevity, consistency and stability. If you're happy with a ?60 limb, and you can't tell the difference, then good for you.
I was just curious as to whether there is any measurable performance difference, and it seems like other than one poster having better sight marks with a lighter, but better limb. There's no other evidence to suggest that an expensive limb provides a faster arrow speed, or can attain more distance/flatter trajectory for the same draw weight as a cheap bow.
 

Timid Toad

Moderator
Staff member
Supporter
Fonz Awardee
Ironman
Lots of evidence, but it's very individual to each archer. I've worked my way through beginner's limbs, intermediate and now top end, and now can achieve 214fps with my current set. I can get a lot more than that with a lighter arrow, but chose not to in favour of downrange accuracy and consistency in all weather. If I set my bow up for flight shooting, I can achieve 260fps+.
Someone else shooting my bow with my draw length might do better or a lot worse. But no entry level limb will do that.

But there is no set, definitive answer. If a manufacturer has done that level of testing, they aren't releasing the data. Some manufacturers will share dfc data, and stored energy of their own product. But you still have to know how to use that in real life. Don't put an F1 engine in a Corsa.

Your best bet is to find someone with a chrono, measure what you are shooting now, and continue to measure as you progress.
 
D

Deleted member 7654

Guest
... I repeat, too many variables.
Limb length, curvature,width, thickness. Thickness of each element, material of each element, glue, curing time, pressure.
Even in the glass/carbon, there is strand thickness, weave, orientation of fibres, number of layers etc etc.
There are an infinite number of permutations and combinations which would make a 30# limb.
Del
 

KidCurry

Well-known member
AIUK Saviour
So there's no empirical data to suggest that a ?400 limb provides a faster arrow speed than a ?60 set of limbs?

The only information is based on manufacturers sayin "faster"?
I have often thought it odd that the figures are supplied for compound but not recurve. Lots of variables for compound just like recurve but they limit them to very specific criteria. ATA, and ISO to a lesser extent, limit arrow weight, draw weight, draw length so comparisons across manufactures can be made. I don't see why they can't do the same for recurve, ie 28" arrow, minimum weight 250grain, maximum draw 29", 68" bow length, mechanical release. It doesn't need to be finger release as it is just a bench mark.

Of course the manufacturers who know speeds have gone up very, very slowly over the years would have a hard job marketing a new bow that was only 0.5fps faster when they can just say 'faster' and sell a shed load more bows. I mean, why would they want too? they can keep giving the same old same old out each time... new bow, faster, smoother, more stable, more forgiving, more accurate... yehh right :)

And while on the subject, the much discussed 'changes in characteristics' of limbs over temperature and humidity. Seriously, you only have to look at the CoE of these materials over 20⁰ to see there is bugger all difference, especially when bonded in a symmetrical sandwich construction and laqured. Just to be clear here, I'm talking about modern materials, not bows like English Longbows that need as much care and nurturing as a Tamagotchi, or the accuracy of an Harrison clock.
The changes in performance of modern materials is tiny over the temperature range normally shot compared to sweaty bow hand effects at 25⁰C and numb fingers at 5⁰C and is just not worth any serious consideration.
 

adrianms

Member
My 2nd set of limbs were SF Elite carbons foams @36lbs (39lb otf) Shot them for 2yrs hitting 100yds with acc's no problem. Recently got a set of 36lb SF Ultimate limbs,
these are giving me 42lb otf & I tried reducing the poundage but the bow just becomes horrible, settled at 42lb & got new ace's to suit.
Until last week I've only shot indoors & the arrows were really fast & hitting the boss hard @18m. Shot last night at 40 & 60yds, bloody hell it lobs arrows at an alarming rate of knots & with very good grouping, all 9's & 7's.
My point being my limbs are rated @36lb but give me 42lb at my draw length rather than the expected 39lb giving me more power. Lovely limbs, very smooth all the way through the draw cycle, but they don't do what they say on the tin. Obviously a little white lie from the SF backroom boys to make their limbs look better. Maybe one way to make their limbs "faster" perhaps?
 

lihp

New member
Thought I would come back to this. I was sat in bed. Playing Zelda on the switch, while watching a bow set up live stream on YouTube (recorded) Jake Kaminski as I in passing wanted to check some parts of my tune.

He initially set his poundage identical to his other bows, 44lbs ish at the clicker iirc. But when he got out shooting, he had to wind it down to get his (same) arrows flying true in comparison to the older limbs. So he had different limbs, at the same draw weight, and same arrows. But the arrows were coming out weak.

From what I recall He ended up down around 41.5 for the same arrow reaction. He did comment he would need to shoot through a chronometer to prove it. But it does suggest that faster limbs may indeed get you further distances for less draw weight. I still find it odd, that no supplier, or press have tested this.
 

Rik

Supporter
Supporter
...
From what I recall He ended up down around 41.5 for the same arrow reaction. He did comment he would need to shoot through a chronometer to prove it. But it does suggest that faster limbs may indeed get you further distances for less draw weight. I still find it odd, that no supplier, or press have tested this.
Maybe I'm missing something, but that's kind of the definition of faster limbs: they send the arrow quicker at the same weight. Hence "faster".

One thing you have to consider: manufacturers may not be keen on there being hard comparisons of their limbs floating around. I suspect it might expose a surprising amount of variability within a model.
 

lihp

New member
Maybe I'm missing something, but that's kind of the definition of faster limbs: they send the arrow quicker at the same weight. Hence "faster".

One thing you have to consider: manufacturers may not be keen on there being hard comparisons of their limbs floating around. I suspect it might expose a surprising amount of variability within a model.
Yes. Manufacturers say "faster" but I was curious as why nothing objective is ever presented. It was a curiosity thing.

They could be 3fps faster than a cheap limb and they can still call it faster. I was curious as to how much difference they really make.
 

lcaillo

New member
The reason nothing objective is provided is that manufacturers need to entice people to buy the latest and the new product is not always better. Hype and flash are more reliable sellers than hard data, which can also be taken out of context. Now I am not saying I don't think they should provide the data, but don't expect it. I would love to see force/draw relationships and draw/energy relationships across different brace heights for every limb/riser combination. That requires a lot of effort, and some standards to be set, and none of that is trivial in terms of cost. Marketing is a lot more efficient way to move product. Having been pretty deep into the consumer electronics industry for several decades, we see the same thing there. And there are good standards and pervasive test equipment there. But you don't see the manufacturers doing the objective testing on their products nearly as much as the hobbyist and the trade press.
 

Whitehart

Well-known member
I don't see how you can get a reliable result. Even if you take two top international archers with the same set up and draw length they will see different speeds. There are too many factors to take into consideration to get the bow and arrows to fly efficiently and give a true result. It is not like a compound where it can be shot out of a machine and the bow configuration and set up is pretty much at its efficient mode out of the box.
 
Top