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View Full Version : Bengal factory DL is 30" mine measures 31"



hunt123
08-19-2010, 06:13 AM
Just finished my draw board, put my Bengal on it and found that when it's drawn back all the way to the hard stop on the cam, the DL measures 31". Factory spec is only 30". Sounds like I'm going to tear something up if I keep shooting it that way. What to I need to change to bring it back to 30"?

bfisher
08-19-2010, 11:32 AM
Not so hard to figure out. The quick and easy thing is to put the next smaller module on it, presumably an F6.

hunt123
08-19-2010, 02:11 PM
I also asked over on AT and have several threads going on it. It seems that the problem may be regarding where the yardstick gets mounted. Mount it wrong and you're messed up. I'm trying to sort out different ideas on where it gets fastened down.

Several posts indicate you mount it so it starts 1.75" from the front of your drawing post. Version 2 indicates you mount it dead even with the front of your drawing post. That's the one that proves to be accurate on my board. The other one puts my bow's DL at 31.75" which is impossible. I tried it and that's what the tape said. Then I tried version 2 and the tape said 30" which would be right with the 30" module.

If a bow's DL is measured from the pivot point to the nock throat, then version #2 is the correct one. I don't know where 1.75" came from or why it's mentioned so much. It isn't right, at least on my board.

Destroyer
08-19-2010, 08:58 PM
If a bow's DL is measured from the pivot point to the nock throat

It is, PLUS 1 3/4" to get AMO draw length. Why AMO? Because with so many different shaped risers it was easier to have this as a standard.

Check your ATA & brace height or do like bfisher said and put the smaller mod on. :)

SonnyThomas
08-20-2010, 10:45 AM
Like the others, checking ata and bh. Sort of describing; get ata within 1/8" and then check draw length. If long twist up bow string. This should bring in draw length, ata, and draw weight.

bfisher
08-20-2010, 11:02 AM
The idea of adding 1 3/4" came from the days of recurves. The distance from the pivot point of the grip to the back (what we call the front) of the riser was usually ABOUT 1 3/4". Also some of the first compound bows had wooden risers shaped about the same. It was necessary to make risers like this to get enough strength to handle the stress.

Along came cast risers, then machined risers made from very strong (7075) aluminum and things changed. Risers come in all shapes and sizes today. Somehwere in the late 70's or early 80's somebody came up with the idea of measuring from the throat of the nock, at full draw, to the pivot point or deepest part of the grip. This they called TRUE DRAW, but it never caught on. So somewhere along the way the 1 3/4" got added to it to conform to what people already knew.

At the time even I thought TRUEDRAW was a dumb idea. Today I can see where it would be a much simpler measurement and less confusing. There is a caveat though, especially in the USA. Bigger is always better here so can you imagine somebody shooting a 30" draw being told that his true draw is only 28 1/4". Man would that stir the pot. Golly, now all of a sudden we aren't as big as our egos have led us to believe.

Of course, that wouldn't helpwith the problem of companies cheating for their IBO speeds nor would it help with people getting set up with the right length bows. There isn't much control for egomania.

Hope this explains a little history. If anybody knows anything else please chime in.

hunt123
08-20-2010, 11:37 AM
Speaking of egos, how about the classic "skydraw". "I'm a man. I can shoot 80# with ease".

If you add 1.75 to my measured 30" DL, suddenly the Bengal has a max DL of 31.75". There's no way Martin is using AMO when they come up with their bow specs. Spec on the Bengal is 30".

I know I'm not 1.75" overdrawn. I have spec length cables and strings, the 30" F7 module, ATA is only 1/8" off, brace height is close. Being a good aftermarket string, it hasn't stretched since I put it on. Peep hasn't rotated at all. You cannot get a 1.75" overdraw with those specs. Martin has to be using the pivot point to nock throat measurement.

Heck, I've sent it in more than once and it always comes back from Martin with that same DL I have now - 30". Same as what their catalog says.

SonnyThomas
08-20-2010, 02:42 PM
If you add 1.75 to my measured 30" DL, suddenly the Bengal has a max DL of 31.75". There's no way Martin is using AMO when they come up with their bow specs. Spec on the Bengal is 30".

I know I'm not 1.75" overdrawn. I have spec length cables and strings, the 30" F7 module, ATA is only 1/8" off, brace height is close. Being a good aftermarket string, it hasn't stretched since I put it on. Peep hasn't rotated at all. You cannot get a 1.75" overdraw with those specs. Martin has to be using the pivot point to nock throat measurement.

Heck, I've sent it in more than once and it always comes back from Martin with that same DL I have now - 30". Same as what their catalog says.

You're losing me here. See diagram above. If you have the 30" mod in then measuring from the apex of the string at full draw to the deepest part of the grip (pivot point) you should have 28 1/4".

Good, bad or indifferent; Measure strings (I know you said they are in specs, but measure anyway). Apply the following to that said in other replies. #1 -Reasonably in time, hold the ata with the buss cable to 1/8". #2 - Measure draw length. #3 - If long twist bow string until draw length is correct - this will rotate the cam. If you have untwist the buss cable, so be it.
Notes; correct ata of a bow is that when max listed draw weight is achieved. Under rotated cam will lengthen draw length. Over rotated cam will shorten draw length.

Go to the link following. Though this is for Hoyts the same principal applies for ata and setting draw length. Weird reading for a single cam, but it still works and it works on every cam system from yesteryear through today...

http://www.archerytalk.com/vb/showthread.php?t=207391

hunt123
08-20-2010, 04:02 PM
You're losing me here. See diagram above. If you have the 30" mod in then measuring from the apex of the string at full draw to the deepest part of the grip (pivot point) you should have 28 1/4".

No, I don't have 28.25". It measures 30" from pivot point of grip to apex of the string. It always comes back from Martin with that draw length as it is now.

Apex of string to pivot point = 30" measured by my tape measure with the bow drawn back to full draw. Measured it yesterday several different times. Always 30" NOT 28 1/4".

Destroyer
08-20-2010, 05:45 PM
Sounds too long. I'm guessing you have already measured the ATA, brace height, etc. Rather strange this problem. What year is it?

bfisher
08-20-2010, 06:35 PM
Martin uses the AMO standard, as do all bow manufacturers. This is an ATA standard measuring system. Now whether they are accurate is another matter. I honestly believe you need to call Martin and ask for Joel or Jeremy and take this up with them.

I can see and even accept a draw length being off by 1/4", but no more than that. I would agree with Sonny in that you should measure the string and cable and everything else you can think of just to have all your ducks in a row before you call them.

SonnyThomas
08-20-2010, 06:35 PM
Can you put up picture of cam, undrawn? This could show if cam is rotated properly.

hunt123
08-21-2010, 05:15 AM
Sounds too long. I'm guessing you have already measured the ATA, brace height, etc. Rather strange this problem. What year is it?

Yep. Measured them all. Within 1/16 to 1/8 of being within spec. I think it's a 2009 bow. Maybe 2010.

SOUNDS to long - maybe, but it doesn't shoot too long. I use a thumb release and have a good solid anchor with knuckle under ear lobe. Our pro shop has checked my draw several times.

hunt123
08-21-2010, 05:17 AM
Can you put up picture of cam, undrawn? This could show if cam is rotated properly.

Here you go.

hunt123
08-21-2010, 05:19 AM
Martin uses the AMO standard, as do all bow manufacturers. This is an ATA standard measuring system. Now whether they are accurate is another matter. I honestly believe you need to call Martin and ask for Joel or Jeremy and take this up with them.

I can see and even accept a draw length being off by 1/4", but no more than that. I would agree with Sonny in that you should measure the string and cable and everything else you can think of just to have all your ducks in a row before you call them.

Lying in bed last night in a sleep fog, I suddenly thought I should do that. :) Will have to wait until Monday though. Someone posted on AT that Jeremy isn't at Martin any longer? I didn't know a Jeremy but have talked to Joel several times.

bfisher
08-21-2010, 01:02 PM
I dealt with Jeremy back in December when I ordered new limbs for my FireCat. It's quite possible he's moved on to greener pastures. Joel is always good to work with. Dawn at Rytera isn't too shabby when it comes to helping.

Montalaar
08-21-2010, 01:28 PM
In my eyes Dawn is quite good at her job. :D

SonnyThomas
08-21-2010, 07:09 PM
Well, I think you're pulling our "chain." In your other post on another site you related of having mixed strings, "cable breaking under serving - had one laying around."

Bottom line; You want the bow's draw length to be exact with the mods, twist up the bow string until the correct draw length is there. I don't really care where the cam is for position as long as the draw length is correct. 10 twists should correct it and maybe untwist the buss cable 3 times.

I'm done......

Destroyer
08-21-2010, 11:53 PM
I use a thumb release and have a good solid anchor with knuckle under ear lobe.

If your shooting the bow well @ 31", I see no problem then. :)

hunt123
08-26-2010, 12:50 PM
I posted this on the other related threads also. Just FYI in case anyone is interested.

Just wanted to let everyone know that I just talked to Joel at Martin and told him about the problem. He listened to all my numbers and agreed that it was all quite weird. I asked him if possibly the module could be making the DL run long but he said if anything, it would be making it a little short.

Then he said that the Moab and the Bengal should have the same DL specs but the Moab is listed at 31". So the Bengal 30" DL in the catalog could easily be a typo. If that's the case, then I'm only .75 off AMO instead of 1.75". He agreed that all the other numbers (ATA, brace, etc) were fine and said he wouldn't worry about it. I'm not going to hurt the bow.

He did say they use the AMO DL as their spec and if the catalog AMO DL was 30", then I should be measuring 28.25" from pivot point to string apex. Since I'm not even close, and the bow always comes back to me from Martin as it is now, then the catalog must be typo'd in that area. Particularly since it's supposed to be the same as the Moab.



I don't think I'd like twisting the string up to take 3/4" out of my DL. My anchor point wouldn't be as solid since my first knuckle would no longer be fitting in the little hollow under my ear lobe. Gonna shoot it like it is. Joel said it won't break and that's good enough for me.

I noticed one or more responders appeared to be a little PO'd by parts of this discussion that took place on another site. I guarantee there has been no "chain pulling" on my part. If I've not communicated my problem as well as I could have, I do apologize for that. Thank you all for pitching in to try to work this out.

bfisher
08-26-2010, 05:37 PM
Well, just glad you got it all sorted out. Now go shoot your bow, OK? Have fun.

hunt123
08-27-2010, 04:42 AM
Well, just glad you got it all sorted out. Now go shoot your bow, OK? Have fun.

Yep! Just finished making another hunting stabilizer I'm totally itching to try out! But I think the wife has other plans for us today. Oh well.....