Need an explaination of Mathews New Binary Cams and Mods

I shot a Mathews Monster ChillR in Michigan and loved it. Shot the same bow at Woods and Water last night (28/70) felt totally different. Valley different and too short for me. Then I shot a ChillX same draw length (28/70) and the length was good and the valley felt like I like it. Come to find out they make different modules for these bows and you can use them on both models. But one mod on a "R" give a different draw length on the "X" and vice versa. Never really figured out which I was shooting on which, and didn't get an answer as if the mods were available to change draw length. Shaw or anyone????

Mathews has a forum might find your answer there

I just got the Chill R. The difference you are feeling is probably these things called rock mods that go on the Chill R and X. They come standard on the Chill X but not the R. When I shot the demo Chill R, which had the rock mods, I could tell a huge difference when I shot my new bow without the rock mods. I ended up getting them put on my Chill R also. Hope this helps.

Besides the standard mods, they have 65 and 85% rock mods. Theses mods are suppose to give you a more solid back wall. The bow you drew that felt like it had no valley most likely had rock mods on it. Also from what I have heard, the actual draw lengths are running longer than the list length. So if you shoot a 28" you may want to get a 27.5". The ZX cam on my Z7 runs 3/8" long. I normally shoot a 26.5", so I got a 26" cam for it and it feels perfect.

^^^ EXACTLY what I was going to say.

The mods do change the draw length. U are correct that the same mod will be a different draw length on the Chill, Chill R, and Chill X. I have the 75% rock mod A on my chill r. That is 30" dl for the R but it would be 31 dl on the X. Also the 75% are silver and the 85% are black.