OK, so my 2002 bowtech tomkat came in the mail today. It has brand new 70# limbs on it but here is my problem. When I shot my friends bow I did not pay attention to how everything was set up. This may sound stupid but any help would be really appreciated.

There is a small rubber piece that both the string and the cable passes through and kind of hooks onto (attatched to the rod in the center of the bow). Is that used for when you store the bow and should it come off before drawing back. The bow seems really tight and I am afraid that I may break the limbs. Is it normal for the bow to feel really tight when drawing or am I doing something wrong. My buddy had his set at 65# but this just seems really tight.