Limbs, life and performance

[taergalger]

I hear you load and clear Dave but are you letting your ‘barebow’ interests prejudice your reading of my posts, equipment is my one self confessed weak point, i.e. I haven’t given it much thought, hence my original question and quest for information.
As it happens, I might not be the techy you seem to think I am, when I gave up archery in 1971 at the age of 14, one of the reasons was because I was disheartened by all the fancy kit other kids kept turning up with, I was a purist, I thought it was cheating.
The other reason was girls, as much as I loved shooting, there was no competition.

[darthTer]

I think that one of the big problems in compiling reliable data on this subject is that everyone is different, therefore giving an infinite number of variables to test.

Someone drawing 31" but is using a 68" bow, is going to put the limbs under more stress that some drawing the same but with a 70" bow. Also, different string materials may also have an effect.

There is also the fact that not every release is performed exactly the same (certainly true in my case...).

With compounds it would be easier to get the reliable data with the use of a hooter shooter, which can perform the exact same shot time & time again - even putting the arrow in the same hole. As far as I'm aware there is no similar device for recurve shooting.

I'm pretty sure that the different manufacturers with have a rough idea about how long a set of limbs should last, but they will never publish them.
eg. Manufacturer A states that their limbs will shoot a minimum of 50,000 arrows. Yet someones limbs fail after 35,000 - leaves the company open to being sued.

[greygoose]

Hi All,
For my part I will henceforth assume that decent limbs do not degrade to any degree worth considering.
Greygoose

[Chris B]

Originally Posted by greygoose

Hi All,
For my part I will henceforth assume that decent limbs do not degrade to any degree worth considering.
Greygoose

I think you're on firm ground there.

[whiz]

As an ex airframe technician and now archer, I can see things from both points of view.
However, even in the aerospace industry, there is no firm data for fatigue analysis of fiber reinforced plastics.
It's well known with aerospace metals and construction.

Ever had a look on what airframe hours are recommended for fullsize high performance fiberglass gliders?

The biggest influence on the theory of unstringing bows is the practice carried out to preserve the performance of organic materials under stress. Ie, wood, and unstringing your English longbow/selfbow.

Limbs of modern construction do not have to be unstrung and there are archers who have reported having bows strung for several years with no measureable decrease in performance.
If in doubt, check your manufacturer user manual and look specifically for the phrase "Unstring your limbs when not in use". I would be surprised if you find it.

I know of one Olympian who used the same limbs for years until a minor delamination rendered them unservicable.
The data of fatigue in limbs is not available widely because it's not considered much of a problem. Probably because it isn't.

[taergalger]

Many thanks Whizz, answers exactly my question.
I didn’t really expect hard facts, I guessed if they existed I would have seen them by now but I was hoping for an experienced well informed opinion and yours sounds just like that.
Until I hear otherwise I will now be able to sleep again!