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View Full Version : Increasing the draw on a TRG conversion



bob cooly
01-11-2012, 03:31 PM
I have a 2011 Onza 50lb draw bow that has been converted to the conventional cable slide setup and will only peak at 45lbs. How can I get this bow back to 50lbs? The strings have been changed but I still am under the specified draw weight for this bow. I am not near a pro shop of any sort and have been doing my own bow work. I think the only way is to twist up the cables 6 turns and see if the draw weight will get back to where it should be, any expert advice would be appreciated.

Spiker
01-11-2012, 03:34 PM
Is the ata and bh correct?

bob cooly
01-11-2012, 03:45 PM
Yes Spiker; all the bow spects are good and the cams are timed, just never been able to get the poundage back after changing out the trg. The bow was right at 52lbs when I got it from Martin last year.

Spiker
01-11-2012, 03:57 PM
If the ata and bh are the same as before - I don't see how the max Dw could change by 7lbs unless the cam rotation (not timing) was way off.

bob cooly
01-11-2012, 04:01 PM
At full draw the string stops on the cams are both very even as they should be according to the Martin manual. Do you think equally putting a few twists in the cable might help?

Spiker
01-11-2012, 04:11 PM
Well yes, it will load the limbs more, bring the ata down and increase dw.Does the actual draw length of the bow match the settings on the modules?

bob cooly
01-11-2012, 04:21 PM
I have not checked the draw length as I don't have a draw board, but have never messed with it since I got the bow at 29".

bowgramp59
01-11-2012, 05:28 PM
twisting cables will do this
retards cams, increases dl ,increases draw wt. , decreases ata, increases brace ht.
untwisting cables will do just the oppisite.

twisting string
advances cam , decreases draw length, decreases draw wt. ,decreases ata , increases brace ht.

untwisting string will do just the oppisite

tighting limb bolts
advances cam, decreases draw length, increases draw wt. , increases ata, decreases brace ht.

i printed this here on the tech forum a couple years ago!

bowgramp59
01-11-2012, 05:41 PM
i also have an onza 3 with 60 lb limbs , i also made the conversion from trg to a cable slide , best i can tell made no difference on my bow, it is very important to have your cables & strings set to factory specks, and it is best to set them to specks under 90 lbs of tention, which requires a string jig equiped with a scale. i have found that when i do it this way my cam timing , ata , brace ht, peak draw are on the money. i know everone doesn't have access to a jig, but this is the best way to do it if possible, good luck!

Spiker
01-12-2012, 05:43 AM
I think you may want to do as suggested above. Having the string/cables dead on the correct spec will almost always bring the bow to where it is supposed to be.
You can anchor one end of the string/cable on a 1/4" nail or hook then put your bow scale on the other end and use a ratchet strap to pull tension
on it. Just be sure to put the same amount on each one, adjust them to correct length, then reinstall.
Also be sure that when the bow is at rest the cam orientation looks like the pic on page 10 of the 2012 manual. (It is on Martins web site if you dont
have the manual)

bob cooly
01-12-2012, 05:59 AM
Thanks guys, since last night I checked the ata and it is off. The Matin website says the ATA should be 32 1/4" for the 2011 model and 33 1/4 for the 2012 model. I measured mine and it is 33 1/2" so the new cables are difinitely needing some tuning. I will use the method of using my bow scale to get them the right lenght. Hopefully this will correct the problem. By the way even in the state it is this bow is very accurate.