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View Full Version : Changing From TRG To Cable Slide. Do I Need Shorter Cables?



MLN1963
08-05-2011, 07:18 AM
Okay guys. I'm going to make the change once I get some answers and hopefully new cables and string from Martin. The TRG is tearing up my new set too.

Here is my question. Martin Customer Service says just swap out the parts and do nothing else to the cables. E.G. no twisting or shorter cables needed. During my conversation with CS and he said they are making all new bows with a cable slide instead of TRG and they are using the same cables as before and aren't changing anything. I told my local dealer that I have a cable rod and slide to convert and he says I don't want to twist up my cables as much as it would take and I need new shorter cables. Without having tried it I would agree. It would be a lot of twisting IMO.

For those that converted your bows over how much twisting did you have to do. How far apart are the twists? Did the cable act like a pretzel?

*EDIT*

It all works good with little to no fuss. Don't worry about it. Read on below.

bfisher
08-05-2011, 07:47 AM
Although the TRG does pull the cables to the side a little more going to a regular slide isn''t going to make that much of a change that would require different cables. If you were going from a CCS to a slide then yes, it would call for 1/2" shorter cables, but I think you'll be OK with what you have.

If you now have the bow's draw length dead on for you then take a pencil and draw a line on the left side of the cam (RH bow) where it passes thru the limb fork. This will give you a good indication of whether the draw length changes when you make the swap. My guess is that the draw will get just a tad shorter, but not very much. Make the swap and see what ya got.

Ford
08-05-2011, 09:05 AM
The pro shop converted mine, they didnt say anything was more difficult or a pain. I saw no differences. But I'm not knowledgable enough to know if there are more twists, or to much cam lean, or anything. Draw seemed close in length.

MLN1963
08-05-2011, 09:12 AM
Barry I need to talk with CS because I think I should start with a fresh set of cables. I really only want to do this once. I am so sick of messing with this bow.

MLN1963
08-05-2011, 06:26 PM
Okay I'll make the change at some point this weekend if time permits.

Sonny, the cable rod they sent was straight. If you think tracking down an offset rod is worth it I'll see if the local dealer has one. If not I'll use what they gave me, straight rod and grey cable slide.

MLN1963
08-06-2011, 07:52 AM
Sonny

It looks like I would have to order that offset rod since the only one I can find today is a screw in Cobra which won't work. My local guy isn't open again until Tuesday and if he doesn't have it I would be the following week before I get it.

I may throw the straight on on and then when I can find a off set try it. I might even have to look at making one if I can find some 3/8" aluminum. If I do that I will need some measurements if you have them.

Destroyer
08-07-2011, 01:52 AM
A few on eBay

http://shop.ebay.com/i.html?_from=R40&_trksid=m570.l1313&_nkw=martin+cable+guard&_sacat=See-All-Categories

MLN1963
08-07-2011, 08:16 AM
Thanks!

I have to call Martin Monday about my cables and string so I will ask about getting one of those too if they will sell directly. I need a SOS rubber to since mine tore.

archerx7
08-07-2011, 08:58 AM
Thanks!

I have to call Martin Monday about my cables and string so I will ask about getting one of those too if they will sell directly. I need a SOS rubber to since mine tore.

If your converting from the TRG to a rod/slide, you'll need the low mount STS, won't be able to mount the SOS to the rod/slide combo.

MLN1963
08-07-2011, 09:32 AM
Jim

I have already mounted the lower STS. I had to remove the SOS already because the rubber tore.

Have you converted any from TRG to cable slide? Do you have any words of wisdom you would like to share? I'm learning as I go so all info is appreciated.

Thanks
Mark

archerx7
08-07-2011, 08:44 PM
Jim

I have already mounted the lower STS. I had to remove the SOS already because the rubber tore.

Have you converted any from TRG to cable slide? Do you have any words of wisdom you would like to share? I'm learning as I go so all info is appreciated.

Thanks
Mark

I've got a FC 400 hanging here as well as a conversion kit, if I can get some spare time tomorrow I'll do the swap and record the numbers before and after.

MLN1963
08-07-2011, 10:11 PM
I've got a FC 400 hanging here as well as a conversion kit, if I can get some spare time tomorrow I'll do the swap and record the numbers before and after. That would be great. What kind of measurements: a2a, draw length change, cam rotation change, cam lean, cam timing?

archerx7
08-08-2011, 07:11 AM
That would be great. What kind of measurements: a2a, draw length change, cam rotation change, cam lean, cam timing?

Mark, Here is what I came up with. Starting point was with the string/cables set to factoery specs, the cams timed and the TRG installed.

DL 29.25" DW 60.1# Brace 7 1/16" Left side A2A 31 7/8" Right side A2A 31 7/8" clearance to Blazer vane 17/32"

Specs with rod/slide installed.

DL 29.25" DW 60.0# Brace 7" Left side A2A 31 7/8" Right side A2A 31 15/16" clearance to Blazer vane 6/32"

The cams remained in sync with the rod/slide installed. The bow had zero cam lean with the TRG and very minimal lean with the rod/slide installed, not nearly enough to be of any concern. I would guess that 1-2 twists in each cable would have brought the DW and brace back to where they were with the TRG, but with that small of a change.........I really didn't see the need. Hope this helps in some way.

MLN1963
08-08-2011, 07:17 AM
Jim

Thanks! for the info! Did you use a straight or offset rod?

Once again this proves how little I know and that I shouldn't assume. I honestly don't know how you can move the cables over so far and not affect A2A but you have proven I was dead wrong. My apologies to Martin for doubting them.

archerx7
08-08-2011, 08:08 AM
Jim

Thanks! for the info! Did you use a straight or offset rod?

Once again this proves how little I know and that I shouldn't assume. I honestly don't know how you can move the cables over so far and not affect A2A but you have proven I was dead wrong. My apologies to Martin for doubting them.

Mark,
That was using the standard straight rod. If you are using high profile vanes such as Blazers, I'm not sure the offset rod would be of much more benefit. The small change in brace shows that the cams will rotate a small amount before the limbs will actually move and affect A2A. My press won't allow me to press these bows without removing the draw stop, and even though I marked it before removal, I most likley didn't get it back in the exact place so that would be the reason the DL never changed, although it would have only changed about an 1/8" at most.

Make the swap, put 1 twist in each cable and go shoot/enjoy your bow. :)

MLN1963
08-08-2011, 08:15 AM
Jim

I took the before measurements, now I'm getting ready to change it over.

I have one question. Which cable goes in what slot on the cable guide? I just want to make 100% sure so I'm asking. I have been wrong to many times already and have filled that quota for the week. And it is only Monday!

MLN1963
08-08-2011, 08:58 AM
I figured out the cable arrangement.Slide isn't as smooth as TRG. specs to come soon.

archerx7
08-08-2011, 09:04 AM
Jim

I took the before measurements, now I'm getting ready to change it over.

I have one question. Which cable goes in what slot on the cable guide? I just want to make 100% sure so I'm asking. I have been wrong to many times already and have filled that quota for the week. And it is only Monday!

Leave the cables attached and just loosen the set screws for the TRG after you get tension off the cables, slide the TRG out of the slot and install the rod and retighten the set screws. The cables will still cross under the rod with the conversion, so which way to install the slide will be obvious. It can only be installed one way where it will keep the cables from rubbing each other.

MLN1963
08-08-2011, 09:14 AM
Jim

You missed my post above Sonny's. However, I happened to do it exactly the way described. Brilliant minds think alike! :cool:

MLN1963
08-08-2011, 10:28 AM
Alright, all the measurements are done. I left the draw stop in place and watched the cables in the modules as well. On the left will be my old settings and on the right the new, You will see that there was virtually no change at all. I had even less change than Archerx7 on some stuff. I didn't simplify numbers to make the comparisons easier. Hopefully my math teacher will forgive me. :o

Draw Weight
61# / 61.5# ---- I don't have a digital scale so it is a best guess but it did seem to increase just a tad.

Draw Length
27-16/32" / 27-15/32"

Brace Height
7" / 6-15/16"

Vane Clearance
1/2" / 1/8" --- Yes, a reduction of 3/8 inch! Gt Velocity Hunter 400 with 3" Vantec VMax vanes.

Arrow Clearance ----- Only after removal of the TRG measurements were taken.
GT 400 .290" diameter = 5/8" clearance
Easton ST Excel .274" diameter = 11/16" clearance

A2A RT side at rest
32-7/32" / 32-7/32"

A2A LT side at rest
32-732" / 32-9/32'

A2A RT side at full draw
28-22/32" / 28-21/32"

A2A LT side at full draw
28-21/32" / 28-22/32"

I also marked the cams with pencil per Barry's suggestion. That cams did rotate slightly, about 1/16" in the direction they move if you draw the string back. Is that advanced or retarded?

There you have it, for all intents and purposes nothing changed but vane clearance.

*Edit* The cable slide was not smooth on the cable rod initially. After a a slight break-in period it is smooth and friction free.

MLN1963
08-08-2011, 11:23 AM
Another thing; Not readily seen is the bow string changing position laterally. Okay, I have my STS dead center of the bow string. So giving the cables a good waxing I removed the guide. As I waxed the cable I notice my STS off center to the string and I thought; "what the heck?" Just by chance in wondering I pulled the cable over a bit like they were in the guide and sure enough the bow string centered to the STS. Finished waxing I installed the guide and again the bow string was centered to the STS. Now, this was on my Shadowcat - long, long riser. BUT if my Shadowcat riser flexes that much with cables not stressing it, isn't there some flex on a shorter riser? Just food for thought. Someone having a short riser could check to see if there is lateral movement. May not be much, but should be there.



You are right about that flex and it is more than I think it should be. I noticed this when I had my SOS installed. From the factory at full poundage the SOS was centered on the string. I had the bow for 45 pound draw weight when I first got the bow. I had to move the SOS to line it up. I shot it that way for a while until my muscles got used to drawing a bow. When I upped the poundage I had to move the SOS back because now it was no longer centered. I think I mentioned this in a previous post and have some pictures in my photo gallery. So yes, the riser flexes a lot!

MLN1963
08-08-2011, 11:29 AM
Another notice. It seemed point of impact changed, more to the right about 1 to 2 inches. I didn't persue more testing for impact. It was just too hot....


I went out and made a few shots. Only a few, it is 108* out there right now!

My point of impact moved too. However, mine moved to the left approx. 1" at 10 yards. I'm a righty, are you? if not I am surprised the POI moved in opposite directions?

I will try a sight adjustment and see if that is enough to fix it. If not I will do the 10 yard tuning bit.

MLN1963
08-08-2011, 11:35 AM
I thought about taking that measurement Sonny! I didn't know what I could use it for so I skipped it. You have to excuse my ignorance, I'm a green horn. Everything I know about bows has come from you guys on this forum. I'm learning quickly but have a long, long way to go!

Teflon sounds better than plastic. My cable slide appears to be plastic. It could be a lot smoother. I may see what the local guy has tomorrow. What is a good replacement if I need to order one or pick one up?

Did you see my response above about riser flex?

MLN1963
08-08-2011, 05:05 PM
Now that I have a few shots on the bow the cables slide is no longer sticking in spots. It must have polished the surfaces to where they slide easily now. It just needed a short break-in period! I am happy for that. :cool:

Sonny, I added the arrow clearance you requested to the specs above.


Yes, I saw about the flex. It's really guite stunning. okay, me; Stress off the riser, stress off the cams equals "Gooder."

Just think, what you are seeing is before the draw. I wonder what it looks like during the draw or at full draw?

Bromz
08-17-2011, 07:33 AM
I changed mine last night and had no problems with the strings. I dont think it is that big of a change.