# Modular Single Cams - Level nock travel?



## RLongwell (Jul 28, 2006)

I've got a technical question that I hope some of you sages can help me with. I just got my newest American Hunter, and in it, Bill Winke reviews the new PSE Mach X. In the review, he makes the following comment:

"I have never been a big fan of modular single-cam bows because most have just one module that affects the size of the take-up track of the cam. The let-out track is unaffected, therefore nock travel can't remain perfect. In most cases, these modular cams force a compromise on anyone with a draw length other than 29 inches. But the X Cam on the Mach X includes both teh take-up and let-out tracks so the cam continues to produce level nock travel at every draw length."

Could someone please explain all of that to me. I assume by "modular single-cam bows" he means any single cam bow where the draw length is adjusted by modules. Is this why some of the bow makers have switched to a draw-length specific cam? Also, how does this apply to, say, Ross bows, which are adjusted by modules? If I get, say a 27-29" model and adjust the module for 27 inches, will I have problems with non-level nock travel?

Basically what I'd like here is help understanding Winke's comments. Please do not respond with "Aw, don't worry about it; it's not a big deal." That doesn't help me understand anything.

Thanks a lot,


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## BearSlayr (Jan 23, 2006)

I think draw length specific bows are better for that reason. On other bows with removable modules as soon as you change mods it affects the nock travel. That doesnt mean that a bow that is draw specific will shoot better than a modular cam bow so long as the nock travel is totally radical.


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## RLongwell (Jul 28, 2006)

So on a bow set, say, at 29 inches, nock travel will be perfectly level, but if you change draw lengths (by adjusting the module), nock travel will be less than perfect, but what you're saying, if I understand you right, is that it won't really affect how well the bow shoots unless the nock travel becomes really off whack?

I'd really like to know, though, what the "take-up track" and "let-out track" is. I've never run across these terms before, although I've been around bows for a long, long time.

On a related note, it seems as if the industry has decided that a 29" draw is the draw length for the "average" person. I don't know about anyone else, but most of the people I see drawing 29 inches are overdrawing the bow. I suspect this is probably because most bows in shops are set up for 29 inches and people just go in and buy them as-is. I am of average build and I shoot 27 1/2" with a D-loop. Most of the bowhunters I know are about my size. It seems to me this is a problem.


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## goat 834 (Sep 18, 2005)

I think this is why Matt Mcpherson(mathews) has draw length specific cams. Its suppose to keep everything in check. It just makes it a bit tougher to experiment with. I would think it would effect everything because I think a modular adj. single cam you are basically changing the draw stop posistion. As far as that goes I don't know. 

For Bill Winke I don't know that everything he says is what he knows,maybe it is. It seems sometimes these writers get there information second hand or maybe he got him a new PSE mach x. So would there be anything wrong with it? Who knows


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## snoot (Jan 31, 2004)

the only thing the module does is control how far the cam rotates. Therefore it does not affect the nock travel, only where the nock starts it's forward motion from is affected. The longer the draw the more the cam will rotate before reaching let off. The reverse happens when using a shorter draw module.


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## bowman78 (Oct 21, 2005)

*module does what?*

the module does affect the draw force rate of the bow which does affect nock travel.............the ramp up rates on the modules have to change to get the same draw weights with shorter draw lengths ........tim


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## RLongwell (Jul 28, 2006)

> the module does affect the draw force rate of the bow which does affect nock travel.............the ramp up rates on the modules have to change to get the same draw weights with shorter draw lengths


Tim, could you please explain how the draw force rate is affected by the module, and what you're talking about when you talk about "the ramp up rates?" I'm ignorant and am just trying to learn.

Thanks,


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## snoot (Jan 31, 2004)

Tim I do agree with the ramp up rates changing with different modules. Which is reaching peak weight and let off sooner or later in the draw cycle. BUT I do not agree with the effect on nock travel(assuming the bow has a level nock travel) other than it changes how far the nock travels backwards on the draw. You are not changing either string track(single cams have 2) on the cam what-so-ever. Just the cable side which controls draw length and let off along with the draw force curve. You cannot have a cam that rotates the same amount and get different draw lengths. The module (on the cable track) controls how far the cam rotates before reaching let off.

I have designed a few cams of my own. Won a couple of state shoots and county shoots with a 80% let off Hoyt Defiant. Hoyt never made one but my buddy killed the state record whitetail her in WV with one of mine.


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