Can you explain a little more as to what it's actually doing. I couldnt imagine being able to adjust a D-Loop with your chin while at full draw.
Yeah, I'm confused by that one. Do you mean you have to adjust your peep rotation with your chin? If that is the case you may only need to adjust the peep. If the D-Loop is loose it still shouldn't effect the peep if you have a good string and set properly. Using the D-Loop to maintain peep position is a band-aide to the bigger tuning issue. And one very easily corrected if you have access to a bow press.
When guys first start putting their own D-Loop on they often do not get them tight enough. They apply plenty of pressure, but the material binds. Adding some string wax to the D-Loop before tightening will usually help with that! If you are concerned with putting a lubricant on the D-Loop you can achieve the same thing with dish soap and then simply wash it off after everything is set properly. In either case, a little goes a long way!
