The dbars were put on many bows in order to prevent damage to the limbs in the event that the bow it dry fired. Which does tend to happen to all of us at one time or other btw. It seems to help reduce the vibration and I guess reduce the damage to the bow limbs. A new answer to this problem is the sts, reds, or baby buggy bumper depending on who you get them from. They are worth every penny, and give you a quick reference guide for the string brace height. Just keep the string and eight inch or so away and you should be fine. Closer and you can split them and will need a new set of rubbers.
They are cheaper, easy to work with, lighter and do actually help with both vibration and dry fire.
The dbars a lot of folks have taken theirs off as their biggest contribution seems to be a bit of added weight to the front of the bow. Leave them on and the now unstrung and it will warp your limbs so there is a definite down side to them.
Just my well,I guess a bit more than, two cents
