Thanks Large Filipino, Those are all thread studs used in the front mount. They go through a plate that fits the bottom of the down tube. It is actually one side of a chain idler so it is pretty heavy before I put the self-locking nuts on is a small tube spacer cut at the angle of the plate on one end and square on the other. This keeps the stud from trying to bend to the angle of the plate across the tube. It is probably 45 degrees or more.