The set screws allow you to maintain centering which means you can get the pads close. The screw head that is on one side is for holding the brake cable (not the straddle wire) out of the way if it is to long and might rub on the tire or scratch your fenders. Once you install the straddle wire holder you will see what we mean. IMO these brakes are a fantastic value. Strong, good looks, easy set up. I would have paid double and still thought it was a great deal.