Trad Gang

Main Boards => PowWow => Topic started by: katman on September 07, 2016, 08:16:00 PM

Title: Bow string length?
Post by: katman on September 07, 2016, 08:16:00 PM
Here is a paragraph pasted from Bob Lee's site regarding string length. Would not a 62" AMO bow use a 59" string? ie. 3" shorter.

"STRING LENGTH
Your bow's AMO (Archery Manufacturer and Merchant's Organization) length is marked on its lower limb. To achieve the correct brace height you will need to use a bowstring of the same AMO length. (Example: An AMO 62" bow requires an AMO 62" string). The actual length of your bowstring will be 4"-5" shorter than its marked AMO length."
Title: Re: Bow string length?
Post by: nhbuck1 on September 07, 2016, 08:23:00 PM
should be 4 inches shorter i believe 3 inches for longbow
Title: Re: Bow string length?
Post by: katman on September 07, 2016, 08:33:00 PM
Here is the AMO guide from a trad gang post, 3"

http://www.tradgang.com/amo/amo.pdf

Don't know why Mr. Lee's site says 4-5"
Title: Re: Bow string length?
Post by: damascusdave on September 07, 2016, 09:10:00 PM
There really is no such thing as a standard that everyone follows

DDave
Title: Re: Bow string length?
Post by: Orion on September 07, 2016, 09:45:00 PM
There isn't a standard that everyone follows, but there is an AMO standard, and it's 3 inches shorter than the bow length for both recurves and longbows. i.e., a 62-inch bow should take a 59-inch string, if it follow the AMO standard.

Actually, the way it's stated is that the correct string length is a the length required to brace the bow at the recommended brace height, which is generally 3 inches shorter than the AMO bow length.
Title: Re: Bow string length?
Post by: LBR on September 07, 2016, 11:15:00 PM
http://texasarchery.org/Documents/AMO/AMOStandards.pdf

AMO says the bow is supposed to be labeled 3" longer than the string master (steel cable) that puts the bow at proper brace.  The string is to be measured at a 100# load (except 8 or 10 strand dacron strings, to be measured under a 50# load).

 
QuoteA Bow String Master designated as AMO 66" (bow length) will have an actual length under tension of 63"."
That being said, a lot of bows aren't correctly marked.  I learned a long time ago to ask for actual string length because there are so many people that are mistaken about what "AMO" means, including bowyers.
Title: Re: Bow string length?
Post by: katman on September 08, 2016, 06:47:00 AM
I was hoping you would post Chad, thanks.

Orion, he contradicts himself saying use an AMO string but then says 4-5" shorter than AMO marked length. Just seems unusual that a man of his experience would contradict himself.
Title: Re: Bow string length?
Post by: dbd870 on September 08, 2016, 07:50:00 AM
I have found on the 4 older Bears I have/had the string needed to be 4-4.5" shorter to get it braced properly.
Title: Re: Bow string length?
Post by: JRY309 on September 08, 2016, 07:51:00 AM
I make all my strings 3" shorter for both my longbows and recurves.That 4" shorter for recurves may have worked for older vintage recurves,they seemed to use a higher brace height in those days.I also like to measure the actual nock to nock length,not all bows are marked accurate.Then I'll make my string 3" shorter.
Title: Re: Bow string length?
Post by: Orion on September 08, 2016, 09:15:00 AM
I agree Katman, he seems to be contradicting himself, but it's confusing so I just chose to clarify the AMO measurement.  

Regarding the example, "An AMO 62" bow requires an AMO 62" string." An AMO 62" string could be interpreted as a 59" string, not an actual 62" length.  Still doesn't jibe with the statement that the string will be 4-5 inches shorter than the Bow's AMO length, though a new string not under tension might be 4 inches or so shorter.      :dunno:
Title: Re: Bow string length?
Post by: DanielB89 on September 08, 2016, 09:25:00 AM
This is in no way against Mr. Bob or his bows.. they are FANTASTIC!! BUT, I owned one once and after reading that on his site, I called him to ask him about string length, it was amazing to me that he didn't know what length string his bow took.  I was told 57.5 for a 62" recuve.  After making a few strings up, it was 58.75 that got the bow at the right brace height.  


I absolutely HATE going by AMO.  Almost every string I've made that was "AMO" i ended up remaking it with the proper length string.
Title: Re: Bow string length?
Post by: Bladepeek on September 08, 2016, 11:24:00 AM
AMO standards are the same as any other standard. People mis-interpret them, ignore them, or don't even understand them. The intent is obvious and admirable, but you simply cannot rely on them being followed by the maker who labled his bow length as "AMO xx".

Not to hijack the op, I recently bought a Java Man Elk Heart and  found that Greg had marked the bow with the AMO length, draw weight @ 28" and actual string length   :notworthy:
Title: Re: Bow string length?
Post by: katman on September 08, 2016, 02:44:00 PM
Bladepeek, That is a good idea Greg has there, hope it catches on.

Daniel, thanks for the input, I was going to contact him but no need to now. I had no intention to bad mouth the bows either. Never had the pleasure to shoot one.
Title: Re: Bow string length?
Post by: nhbuck1 on September 08, 2016, 02:47:00 PM
i just emailed them about the length i will let ya know katman
Title: Re: Bow string length?
Post by: forestdweller on September 08, 2016, 03:17:00 PM
It depends on the bow and the string material along with your desired brace height.

My current recurve needs a string that's 4" shorter to get the high brace height that it shoots best at and it still needs to be twisted up to maintain that brace height.

I've also used a string that's 3" shorter than the bow but the bow was too noisy.
Title: Re: Bow string length?
Post by: frank bullitt on September 08, 2016, 07:10:00 PM
Standards for who?  
That was a Big joke!

Take a Pearson, Bear, Wing, Shakespeare, etc from that era, 60" recurve and see what lengths?

Who was going to police or audit these companie?  Fines,
Title: Re: Bow string length?
Post by: katman on September 08, 2016, 08:10:00 PM
Frank, AMO, Archery Manufacturers and Merchants Organization set the standards in 1986 so the earlier era bows were made before this. I think a standard is a good thing for manufacturers and buyers unfortunately some do not follow it as relayed by the string makers frustration who posted. Don't think a police is the answer, just verify from the bowyer what he did. Certainly would make it easier for all if the standards were followed by all.
Title: Re: Bow string length?
Post by: frank bullitt on September 08, 2016, 08:21:00 PM
No Katman Amo was originated in the 60s!

Just to clarify, I built strings for Bob and Rob.

Amo was before the wheeled bows!
Title: Re: Bow string length?
Post by: SteveB on September 08, 2016, 08:51:00 PM
There is no reason a bow (other than a warf/frankenbow etc) should not come with the string length needed for suggested brace height. Somewhere in the build process it was braced with the correct string.
Title: Re: Bow string length?
Post by: frank bullitt on September 09, 2016, 06:28:00 AM
Yes,  SteveB they should!

Chad, LBR made this same statement,  request not to long ago.

Amo is a word loosely used by many in the archery biz!
Title: Re: Bow string length?
Post by: katman on September 09, 2016, 07:18:00 AM
Frank, I was going by this data,  http://texasarchery.org/Documents/AMO/AMOStandards.pdf
Title: Re: Bow string length?
Post by: LBR on September 12, 2016, 11:58:00 PM
I don't mean this as a slam against anyone, and I won't call any names, but in the last 20+ years I've been tinkering with strings and asking questions one thing is for certain...a lot of very well known bowyers (some former, some still making bows) don't know diddly about strings. I've seen Flemish strings called "less accurate and could be dangerous"...but shipped with some bows anyway.  I've seen a warranty state that it was null and void if a Flemish OR dacron string was used (you read that right--warranty void over dacron).  I've lost count of the times I've heard the string get blamed for everything from delaminations to limbs twisting to noise to whatever.  Saw one guy (not a bowyer) claim his string made his bow pull 4# heavier than the 14 strand Dynaflight '97 string that came with it--everything else exactly the same.  Drives me nuts...

I don't know squat about making a bow, and won't hesitate to tell you I don't.  I have been studying strings and string materials for over twenty years, and that includes asking bowyers all sorts of questions.  IMO, some of them are great and honest but just a bit misinformed. Others, well...

I've been up and down and round and round with several about marking their bows correctly according to AMO, or simply marking the actual string length (ASL) on the bow.  That tiny bit of ink would make life so much easier for everyone involved, but...so far nobody I spoke with would agree to it.  Good to see some are.

Like Frank noted, AMO is a word that's used very loosely, especially in our side of the sport.  Lots of people that use it don't know what it actually means.  Best way to get the correct string length for a bow...measure one that fits it.
Title: Re: Bow string length?
Post by: frank bullitt on September 13, 2016, 07:01:00 PM
Amen!  Chad.

If folks only new the battles to overcome!
Title: Re: Bow string length?
Post by: LBR on September 13, 2016, 08:55:00 PM
The most recent is a material (BCY-X) getting blamed for a certain brand of bow failing.  When this material came out, I bought a Samick Journey to test it with.  Been shooting it going on four years, at least one accidental dry-fire at full draw, it's still doing fine.  For years Dan Quillian, Fedora, and Shrew promoted 450+ which has even less stretch/creep than BCY-X.  For some reason it's always the string's fault....
Title: Re: Bow string length?
Post by: nhbuck1 on September 14, 2016, 12:01:00 AM
What length strings do the Bob lees take then?
Title: Re: Bow string length?
Post by: frank bullitt on September 14, 2016, 06:36:00 AM
Well,  the older Customs took around 4.5"
shorter.

They have made changes,  and many bows since. Best to give them a call.
Title: Re: Bow string length?
Post by: T Folts on September 14, 2016, 07:41:00 AM
My Longbows take a 3" shorter string to be at proper brace.
Title: Re: Bow string length?
Post by: LBR on September 14, 2016, 08:21:00 AM
What Frank said on the Bob Lee's--it depends on the bow.  I try to get the length of an existing string that fits and use that to go by.
Title: Re: Bow string length?
Post by: Bladepeek on September 14, 2016, 11:07:00 AM
I agree with Chad. It would be so nice to see bowyers mark the ASL on the bow, but few do (thanks Gregg Coffee for marking yours).

It's just not that difficult to get a string with which to brace the bow (my HS English teacher would have been proud of me   :) )  You might have to over-twist the daylights out of it to get the desired brace height, or un-twist it way beyond where you would normally run the string, but since you are not drawing the bow - only stringing it to brace height, that's not really a problem. When you have the bow at the desired brace height, measure the string and you know what you want to order.