Buckfevr

What is the effect of shortening the string and cable while maintaining the optimal cam position?

Hunting1

I would like to know that too. I'm sure it would shorten the draw length and increase the brace height and drop the draw weight Right?
Thanks Chuck

Good Luck

CHUCK

CG

I don't think it would drop the draw weight but I think it would increase it since you are pre-stressing the limbs.

"What we do in this life echos an eternity"

jim243SRC

shortening the string and cable the same amount(cam remains in same pos.) will shorten the axle to axle, increase brace height, increase draw weight, draw length would change very little.

BobCo19-65

jim has it right, but it would slightly increase the draw length.

I would mess to much with experimenting with it. I'm sure it would void warrantees as well as setting up a possible dangerous situation.

JOE PA

I have done this to two bows, that is, experiment with reducing or increasing the axle to axle length by using shorter or longer string/cable sets. I will spare you the details, but I found that with the first bow, a 40" a to a bow, the draw weight increased approx. 10 pounds for every inch I shortened the string and cables. There was not a large increase in draw length with this size bow, but it increased a bit since the brace height increased. The draw length increased slightly less than the brace height however. With the second bow, I actually started with the shorter axle length, 34" originally, which is what I determined I needed to get the 7+" brace that I wanted. The cams on that bow barely started turning at 75#! Too much for me. I ended up lengthening the bow to 36" axle to axle and the brace height also dropped to
6 1/4". The draw weight dropped from 75+ to 65, but that was with the limb bolts backed out a good bit. I obtained other limbs, and now the draw weight is 62# with the limb bolts bottomed out. The bow has hard cams, so that is enough weight for me. If I tried to increase the brace and reduce the axle length, I am sure the draw weight would increase again. The draw length would probably also be too long for me unless I changed the timing position of the cams which I do not think would be a positive change. ( I don't have access to other modules, since the cams are from an obsolete bow.)

Avoid the inevitable until it is absolutely unavoidable!

Buckfevr

It wasn't so much from tinkering as it was simply from changing out the string and the cables simultaneously that I noticed that things were different. And I had really pushed the strings and cable as I didn't want to change out before the season was over. While I had maintained the optimal rotation through out, it was only done by shortening up the cable. And I do change out the cable much more frequently. I think that I was on the third cable with the same string. I'll be honest, I just never gave much thought to the string stretching out.

Having changed both out, the thing that I noticed right off was that the whole system was tighter, crisper, but also the draw weight felt considerably heavier. Then the thing that I really noticed was the performance. The bow was just spitting out the heavier arrows. Now I went and measured the brace height and it was a quarter inch longer than what it should be. Fortunately I had the bow chronoed just before the string change, so I'll be able to compare. I'm also going to take good measurements right here soon once I have it all tuned up.

It was just interesting to me. What it looks like is that shortening up the string and cable while maintaining the optimal cam rotation, increases the braceheight, decreases the power stroke a little, increases the drawlength slightly, preloads the limbs a bit more and increases the peak draw weight. I think the performance gains are largely the result of the draw weight increase overwhelming the small decrease in the power stroke.

It just got me thinking about the bow, the whole system. Which is fascinating in its complexity.

But it also got me thinking that maybe I should check the specs periodically and maybe put a few twists in both the string and the cable and tighten things up from time to time.



Edited by - Buckfevr on 01/30/2003 21:22:48

Big Country

Shortening cables gives you longer draw length, higher draw weight.
Shortening main string gives you lower draw weight, shorter draw length.

As long as you keep the twin cams in time, or the single cam within its proper rotation range, you can move brace height, and axle to axle a fair amount without stressing a bow.
When I say a fair amount, I am talking like 1/4", maybe even 3/8" from factory specs for axle to axle, and brace measurements.
Most bows I have played with seemed to perform best at, or very near the factory settings.

NRA,UBP,BASS Member
New Stanton,PA