A good example of what not to do!

[matt_d]

G'day everyone,
Well I thought tonight I would head on down to the range and get in some last minute practice for the LB100 which starts tomorrow. I was shooting my new pride and joy - a Bernardini Cobra 21 inch riser and Hoyt 900cx carbon foam limbs, pulling 50# @ 29".
What a great bow! It's been a long time since I had been enjoying my shooting as much as this. Everything was working, I was putting in some really good groups as you can see from the pic below shooting from 30 metres. One of my best.

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Then, about 2 ends later I was coming to full draw... Must have pinched a nock or something because I remember seeing the cock feather rotate slightly in my peripheral vision. By the time this information actually registered up in the top of my noggin, it was already too late and the release was underway. CRACK! dry fire!
After the big noise the next thing I remember is seeing the top limb laying on the ground in front of me.. I rushed over to inspect it - phew.. it was fine! Then I looked at the lower limb still attached to the bow I was holding in my hand, and this is what I found!

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Completely blown apart the limb tip, and snapped the loop of the TS-1 Plus string!
I haven't yet figured out what the exact breaking strain of this string was for the number of strands... but the forces must have been tremendous! Unless of course, the delamination of the limb tip has cut it's way through the string. Seems unlikely based on the way the string has broken. Oh well... back to the drawing board! What else can you do but laugh and treat it as a valuable lesson (in more than one sense of the word). I guess I'll be shooting something else tomorrow!
Cheers,
Matt

[Mick Smith]

That's a stroke of bad luck Matt.

Will you be able to buy yourself just the one replacement limb for the bow? You will probably have to buy a pair I suppose.

Mick

[woody]

Go to the classifieds on Archers Forum, ILF limbs come up for sale here all the time.

I got a very nice set of Win & Win for $300 a month or so back.

[Len]

Crikey ! That would have givem you a helluva fright, I know it would me Bad luck mate , maybe it means you'll have better luck at the LB100

[Gringa Bows]

Bugger

[Glenn]

That's no good Matt, that would be very dissapionting...Glenn...

[GrahameA]

Morning Matt

Hoyt 900cx carbon foam limbs

Not good. I would not have expected them to fail from a single dry fire. I would even ask the question, "Did you dry fire"? Or did they limbs fail and you ony assumed you had a dry fire? There seems to have been a few C3 limb failures if the postings on AF are anything to go by.

See if you can get replaced under Warranty. Or at least get a comment from Hoyt.

[matt_d]

Thanks for the feedback guys...
Len, first time I've ever had anything explode like that.. definitely a change of undies experience.
Yeah good idea Woody, since there's definitely no possibility of buying a single limb.. I might look at a used set of W&W's or perhaps this is a good opportunity to try the new Border HexV's. The question is - is anybody in the market for a single Hoyt upper limb?
Grahame, although it's hard to be certain because these things happen in the blink of an eye -it definitely felt wrong and the bang wasn't heard I think until the bow reached brace height.
Probably my fault I have heard plenty of stories about the G3's "exploding"... It's a possibility that the lower limb tip was a weak point and could have perhaps failed in the future from something far more mild. It's also been brought to my attention that the lack of padding in the string loops could be to blame.. Definitely food for thought
Cheers,
Matt

[buzz]

Crikey. Definately unexpected after reading that Archery Forum thread about them testing Hoyt limbs.

What limbs are you using for 50# @ 29" on a 21" riser? Any pics of the riser ?

[longbowinfected]

Is there any chance that the damage was actually caused by the string failing.
Your string, from the picture looks like a Flemmish twist.

In the last 5 months with barebowers I have stood next to 6 string failures and they were all Flemmish strings busting at the same point as the damage in your pix.....one of them was yesterday to Richard Husselbee at the Canberra shoot on his longbow. It was a softish bust you could sort of hear a high speed unravelling.....he still shot a 4. The others went off like cannons. One of them was when I had just braced my bow and was about to put my bow in my stand.

I do not think any of the stringmakers involved make bad strings.....I wonder if there has been a bad batch of stock material......just worth considering.

Kevin

[DylanK]

That really sucks. Very nice shooting though

[Alex]

This happened to me this afternoon. I was just shooting in my backyard. I had shot two sets of arrows already and was going to shoot the first arrow of the next set. After release I heard a 'plack' and went to check the bow and there it was. I was lucky this time, some time ago it happened the same but without any warning. The string blew completely. It freaked me out! Both dacron flemish twist strings.

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[longbow steve]

No good Matt, Has the tip been cut through? I see the string has cut down through the limb. If the tip is intact I'd say it has cut after delamination and supporting a dry fire theory .
Any chance I could disect the broken limb and post pics of it's contents? Happy to pay postage or purchase the pair if the price is right . Steve

[Stickbow Hunter]

Sorry to see that happen to your bow Matt.

Alex,

I would think that your string nock on your bow has a sharp edge which is cutting your strings. I would suggest checking and rounding off any sharp edges to stop this happening again.

[Alex]

I reckon you're right Jeff.
Tomorrow I am going to round up the edges on both limbs and get myself another string.
Thanks for the input.
Alex.

[GrahameA]

Morning Kevin

Is there any chance that the damage was actually caused by the string failing.
Your string, from the picture looks like a Flemmish twist.

In the last 5 months with barebowers I have stood next to 6 string failures and they were all Flemmish strings busting at the same point as the damage in your pix.....one of them was yesterday to Richard Husselbee at the Canberra shoot on his longbow. It was a softish bust you could sort of hear a high speed unravelling.....he still shot a 4. The others went off like cannons. One of them was when I had just braced my bow and was about to put my bow in my stand.

I do not think any of the stringmakers involved make bad strings.....I wonder if there has been a bad batch of stock material......just worth considering.

Kevin

In my limited experience with Flemish Strings strings unravel due to couple of reasons:

they are not well made to start off with - usually not tight enough when being made - or the length of the section where the string doubled back onto itself is not long enough
users let them untwist - they have to remain twisted or they will come undone.

As to strings breaking - they will do that if they have been shot enough. However, the onus is on archers to check their strings for wear - and I have seen a few strings that I would not touch but the owners happily use them.

Nocks that are not properly formed or finished are very hard on strings and will lead to the early demise of the string. I have seen more than one bow that has nocks that I would take to with a file, fine emery paper and/or some burnishing material.

[pdccr]

Thats unlucky mate, i've never used a flemish string but im in the process of looking for an tillering string if someone has one, or an easy way to make one withouot dacron.

[longbowinfected]

Thanks Grahame.

The Flemmish that I had break on me was only a few months old with comparatively minor use pattern.
I routinely make 2 new strings for the two bows I use over Christmas and keep the old ones as emergency spares. I change to a new string at tax time so with continuous strings I have luckily not had a failure in my first two and a half years shooting longbow. That memory of being bow slapped in the noggin as I strung my bow will stay with me forever.....hit me front on and really made my eyes water......consequently my teeth are on edge about using Flemmish strings [rightly or wrongly].....they bite.

Kevin

[GrahameA]

Morning Kevin

....consequently my teeth are on edge about using Flemmish strings [rightly or wrongly].....they bite.

My experience suggests that Flemish strings are no more prone to failure than endless strings. I have one on a longbow that has to be around 7 years old and it is still in good condition. I have another that it is on a target recurve and it has shot plenty of arrows and is still fine.

There is more to making strings and cutting nocks at first meets the eye. That is also true of most things in archery. Being the inherent conservative that I am I have bound the splice on a few strings - a sneaky move if you are concerned about they unravelling.

Now, if people are really concerned about them coming undone then they should make them like a piece of rope and then back splice the loop into the string the same way as you splice a loop into a rope. They will not come undone.

As a general approach, it is not the big things in archery that get you rather the small things so it is probably a good move to "sweat the small stuff" - pay attention to the detail.

[longbowinfected]

Grahame,

fair enough.....after all it is a small sampling......but it has been quite compelling.
I really do like the look of them.
But I prefer the endless loop with nock serving [double served].
Up to this point in time I have not been near anyone with an endless loop failure.
I have been next to a number of dry fires on longbows with enless loop strings without limb damage or string damage but must say so far glass backed flat/longbows seem much tougher and resilient than some of the really expensive compound and recurve rigs when dry fired [again small but significant bits flying everywhere samples].
I was really impressed with the duality of body language when Richard Husselbees string went. No sign of panic, look of amazement, still concentrated one eye on his aiming point whilst string came apart "whirr...bang snap" and still scored a 4 at 30metres on a 80 cm face at 12 o'clock."
changed strings, set up nocking points then shot his best ends of the day on a hard, hot and windy day.

Kevin

[Alex]

Cutting nocks ...... an form of art itself within the art of making bows.
Also carving handles , that's what takes me so long to finish my bows.
But in the end , that's what makes one proud, have made a bow that's better than the last one.
Alex.

[GrahameA]

Morning Kevin

Enjoy Canberra?

I really do like the look of them.
But I prefer the endless loop with nock serving [double served].

May I suggest a two colour endless string then.

Up to this point in time I have not been near anyone with an endless loop failure.

An experience to look forward to.

I have been next to a number of dry fires on longbows with endless loop strings without limb damage or string damage but must say so far glass backed flat/longbows seem much tougher and resilient than some of the really expensive compound and recurve rigs when dry fired [again small but significant bits flying everywhere samples].

Yep, they are amazingly strong. Although a plain dry fire with a compound or a target recurve should not be that destructive. I had a nock fail on an arrow with a target recurve once and the metal nocking point did a nice gash on my lip when it came off the string. Since then I only use tie on nocking points. See, only takes one lesson for me to learn.

The real excitement with compounds is when strings break or limbs fail. They terrify me - and I am at the other end of the line. Recurves delaminating also do not do much for my heart rate either. However, my experience suggests string just don't break (ignoring Kevlar)- there is always some warning of the impending failure and the Archer fails to notice it.

[matt_d]

Well upon a bit closer inspection it definitely looks at though it's been the delamination causing the string failure.. I have found small fibres of string between several of the laminations. All with very sharp edges - it makes sense..
Definitely would have expected more in terms of durability from these limbs though... I too read the post on Hoyt limbs on AF and it surprised the hell out of me too.
The reinforcing material over the limb tip (appears to be a resin of some description with some crosshatched fibres, possibly micarta?) has been completely punched through and looks like this is where all the carnage started.

Buzz - I was using 44# mediums on the 21" riser (64" total) to get my 50# @ 29".. Had quite a bit more preload adjustment so could have comfortably gone higher. Can't say enough good things about the Bernardini Cobra riser - a real good alternative to the DAS and Tradtech offerings. The black anodized finish is superb and has an internal weighting system up to about 300g from memory. It also has a radiused shelf so can be shot from the shelf or elevated rest.

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Steve - You are more than welcome to what remains of the limbs, all yours mate. PM sent.
It will be incredibly interesting to see them dissected.

Cheers,
Matt

[Coach]

The Hoyt 900cx carbon foam limbs have been coming under a bit of scrutiny lately , they are not straight and have been delaminating .
The only reason a string will be cut through at the loop is because the string nock has sharp bits there .

[motty]

I've had two strings break on two bows in the last year in the same spot in the loops. The coloured strand only in a flemish string.
No rough spots on the limb nocks. No problems with american made strings. Thinking of going to endless strings

[buzz]

Will an Endless String better a Flemish string? they seem to be failing where they contact the limb, not where the end of the string integrate back onto the main part of the string. They will have the same number of strands running over and around the nock ends. So would you serve the ends of a endless string.... and if so... would serving a flemish twist nock ends beneficial?

[ed]

when making strings for very heavy bows I serve the loops too. Not that hard to do when making the flemish strings, and with double the number of fibres of an endless loop string it should be even stronger. The serving is only going to stop the wear and tear, and has no effect on the strength of the string - think about that and an endless loop string and you would rather do what I do than use an endless loop string ever again.