Hoyt Spiral X cam & 1/2 Draw length Change
- Thread starter inthemiddle
- Start date
Active member
Would a shorter bow string do the job?
Shirt
Well-known member
If it's a Pro Elite with Spiral X cams, then it's 2009 edition.
Pro Elite was released in 2004, was on Spiral cams 2004, 2005 and 2006. C2 cams for 2007, 2008. Then Spiral X cams for 2009.
So you've probably got a 2009. The tune chart for this is here. However, if you've got a 3.0 cam it should be 29.0" draw to start with. There's the ability to mess around +/- 0.5" using the cables on these bows, but 0.75" sounds like something is wrong.
Start by checking the axle to axle, it should be 39 7/8" measured between the centre of each axle, or very close to that. If it's over 40.5" then you need to put twists in the yoke cable to get it back - how old are the strings? It may be a case that they're just very old and have stretched.
If you get it back to box specs (ie 29.0") and it's still too long, then you can install the peg on the bottom cam in one of the other holes. Standard is the furthest away from the string (see lowest circled bit in picture below), the other holes knock off draw length and increase holding weight. You'll need to retime with the control cable but it'll drop your draw length.
In terms of how you set these up, it's pretty straight forward. You mess with the yoke cable (the one that splits and attaches to the top axle) to get the draw length roughly right, bearing in mind this also impacts axle to axle and therefore draw weight. Once that's right, you use the control cable (the one that doesn't split and isn't the string) to get the timing between the cams right, so that the peg on the bottom cam and the flat spot on the top cam hit at the same time (or however you prefer). Then you play with the string to fine tune your draw length.
If after all this you really do need shorter cams, you're in a bit of a pickle. On the far right of the tune chart you see it refers to Cam Family. You'd be going from family 2 to family 1, which means you'd lose between 3 and 5 pounds of draw weight. Not sure how important that is to you. The issue you'll have is finding them. Hoyt cams like this ran in a series:
Pro Elite was released in 2004, was on Spiral cams 2004, 2005 and 2006. C2 cams for 2007, 2008. Then Spiral X cams for 2009.
So you've probably got a 2009. The tune chart for this is here. However, if you've got a 3.0 cam it should be 29.0" draw to start with. There's the ability to mess around +/- 0.5" using the cables on these bows, but 0.75" sounds like something is wrong.
Start by checking the axle to axle, it should be 39 7/8" measured between the centre of each axle, or very close to that. If it's over 40.5" then you need to put twists in the yoke cable to get it back - how old are the strings? It may be a case that they're just very old and have stretched.
If you get it back to box specs (ie 29.0") and it's still too long, then you can install the peg on the bottom cam in one of the other holes. Standard is the furthest away from the string (see lowest circled bit in picture below), the other holes knock off draw length and increase holding weight. You'll need to retime with the control cable but it'll drop your draw length.
In terms of how you set these up, it's pretty straight forward. You mess with the yoke cable (the one that splits and attaches to the top axle) to get the draw length roughly right, bearing in mind this also impacts axle to axle and therefore draw weight. Once that's right, you use the control cable (the one that doesn't split and isn't the string) to get the timing between the cams right, so that the peg on the bottom cam and the flat spot on the top cam hit at the same time (or however you prefer). Then you play with the string to fine tune your draw length.
If after all this you really do need shorter cams, you're in a bit of a pickle. On the far right of the tune chart you see it refers to Cam Family. You'd be going from family 2 to family 1, which means you'd lose between 3 and 5 pounds of draw weight. Not sure how important that is to you. The issue you'll have is finding them. Hoyt cams like this ran in a series:
- Spiral
- C2
- Spiral X
- Spiral Pro
- SVX
inthemiddle
Active member
Thank you so much for this
The bow is old stock but new. I picked it up from Ebay a few years ago from an international archer who was selling off loads of gear that I assume he accumulated over the years. As it's setup now, measuring from the berger hole + 1.75 it has an AMO draw length of 29.6". If I can get it to 29" I really want to keep it as it's such a nice bow. I've added a few pics of the spec of the bow. Everything looks good but the brace height is rather high measured from the throat of the grip at just under 8.75"?
It needs a restring anyway as a messed up the main bow string trying to fit a peep without a bow press. ( I have a bow press now)
So do you reckon it will tweak to 29"?
Last edited:
inthemiddle
Active member
Had a tweak and a twiddle lol. It's now 29 1/8, with an 8.75" brace height and 40" axle. Only down side is it dropped the max poundage to 54LB's It shoots really nice though.
It shoots really nice though.
Shirt
Well-known member
Good start - ignore the brace height, that's just a side effect of everything else. Keep twisting the cables to get the axle to axle right and that should get your poundage back, they're a bit sensitive to this when set properly.
This cam rotation here:
can only honestly be described as dogsh*t. There's meant to be a gap of 10-12mm between that part of the cam and the string. Put a metric ton of twists into the string and get that gap back, when combined with the axle to axle being right should get you to somewhere around the right space. If you're lucky, because you've got the draw stop in hole number 2 (bottom cam), it will even come up a bit short.
One option that I've done before, particularly when dealing with strings that are clearly not the right fit and are of undeterminate vintage, is just tie knots in them to get the length right and then make a new set that matches the ones with knots in. I wouldn't recommend leaving the knots in for a permanent solution, but they won't be an issue if you're going to just draw it, weigh it, check timing and draw length etc.
(Full disclosure: I shot an entire season once with a knot just beneath the split of the yoke because I was too lazy to make a new cable - Ultratec XT3000s with Spiral 5.5s)
This cam rotation here:
can only honestly be described as dogsh*t. There's meant to be a gap of 10-12mm between that part of the cam and the string. Put a metric ton of twists into the string and get that gap back, when combined with the axle to axle being right should get you to somewhere around the right space. If you're lucky, because you've got the draw stop in hole number 2 (bottom cam), it will even come up a bit short.
One option that I've done before, particularly when dealing with strings that are clearly not the right fit and are of undeterminate vintage, is just tie knots in them to get the length right and then make a new set that matches the ones with knots in. I wouldn't recommend leaving the knots in for a permanent solution, but they won't be an issue if you're going to just draw it, weigh it, check timing and draw length etc.
(Full disclosure: I shot an entire season once with a knot just beneath the split of the yoke because I was too lazy to make a new cable - Ultratec XT3000s with Spiral 5.5s)
inthemiddle
Active member
Thanks so much for this. Your input is invaluable. This sort of information is like gold dust to me as you can't learn this stuff in a book, can you?
The pics I listed are the before ones Ill take the after shots when I get chance, The said dog Shi*t gap is now about 8mm so getting there
inthemiddle
Active member
Here is the state of the cam rotation at the moment. How do I get the draw weight back? I reduced the draw length by shortening the string, and got the timing back by adjusting the control cable
Shirt
Well-known member
Draw weight is directly linked to axle to axle, so if that is still at 40" or just over put some more twists in the yoke until it hits poundage. Then adjust everything else as necessary. If the axle to axle comes in a bit under what the book says in order to get poundage that's fine, as long as you can then get the draw length right with other cables / string.
Helpfully, as it's on the older Spiral cams you've still got the timing marks that sit either side of the limb and will tell you if you're doing anything really stupid - as you've got it now is between those marks so indicates you're getting close to factory specs!
Helpfully, as it's on the older Spiral cams you've still got the timing marks that sit either side of the limb and will tell you if you're doing anything really stupid - as you've got it now is between those marks so indicates you're getting close to factory specs!
inthemiddle
Active member
Nice one. Ill have a play with it some more once I get it re-strung. Thanks again for the inputDraw weight is directly linked to axle to axle, so if that is still at 40" or just over put some more twists in the yoke until it hits poundage. Then adjust everything else as necessary. If the axle to axle comes in a bit under what the book says in order to get poundage that's fine, as long as you can then get the draw length right with other cables / string.
Helpfully, as it's on the older Spiral cams you've still got the timing marks that sit either side of the limb and will tell you if you're doing anything really stupid - as you've got it now is between those marks so indicates you're getting close to factory specs!