Blodg

I thought I would share my findings on twisting the cables on the new binary cam, take it or leave it.

I had read a few times that let-off can be changed by twisting the cables. One message board post said to put 3 twists in the top cable and take 3 twists out of the bottom cable and the let-off will go from 65% to 80%. My 27 1/2" Allegiance was right on the DL but the post was about 3/4 out in the slot and the let-off was at 69% as received. I wanted to shoot 80% let-off so I moved the post to the end of the slot and got 80% but now the DL was accurately measured on a jig at 27 3/4". I was glad to hear you could change the let-off by twisting the cables because I wanted to put the post back to the 27 1/2" location and then twist the cables to get back to 80% let-off.

Not so fast. To make a long story short I tried every combination of twisting the cables. I twisted both cables, removed twists from both, twisted the top while removing from the bottom and vice versa. I tried adding and subtracting twists from the string along with the cables as well. I never did more than 3 twists to stay within the recommendation from BowTech. My results revealed that the let-off did change on some combinations but SO DID THE DRAW LENGTH! For example, putting 2 twists in the top and removing 2 from the bottom cable took the let-off from 69% to 77% but the draw length also increased from 27 1/2" to 27 3/4". Twisting the cables had the same net effect as moving the draw stop.

I have a feeling that the people who say they increased the let-off by twisting the cables also increased their draw length slightly. I took all my measurements in a jig that draws the bow back very slowly while monitoring the poundage so a change of 1/8" can be seen easily. Then again, maybe other people have been successful changing the let-off while maintaining the DL but my bow did not yield the same results.

Since I was not able to get 80% let-off at 27 1/2" or less I decided to swap out the cams to 27" because 27 3/4" is just too long for me (5'-7" tall). I am not dead set on 80% but the binary cam bows feel so much better and have the best valley when the post is at the end of the slot. I have since been shooting with the draw stop near the middle of the slot and it doesn't do the bow justice.

Techy

Thanks as always for the great info.

ewolf

Blodg Good post. You also have to think you are talking 1/4" on the draw length. Odds are every bow would act the same, however most people will not notice 1/4" change in draw length.

alain

I did the same thing as you i order a set of 27.5 to replace my 28 it came at 28.5 at 80% way too much for me.

Blodg

ewolf, I agree 1/4" may not be much to some people. The reason it was for me is because I knew I was between a 27 and 27.5" DL from the get-go and while 27 1/2" felt a tad long increasing another 1/4" pushed it too long. I learned a long time ago that for the best accuracy it is better to be a tad short than a tad long on the draw length.

I will say that for those thinking of ordering a binary cam bow I have heard that since I got mine they have started making the cams so that they are at the specified DL at 80% let-off. The draw lengths have been right on for the most part so if you are ordering one you can trust that it should be close. If I would have not had to move my post to get 80% it would have been OK with the cams I ordered.

ijimmy

I hope this thread makes pepole think twice before messing with something the factory says can cause a dangerous situation . We shoot our bows day in and day out without thinking about them too much as far as safty goes , and things can go wrong with them and result in bad situations .