120 mm over locknut dimension spaced track hubs are designed to give a 42mm chainline. The RD with a 103 bb will give 45mm chainline. just put the chainring on the inside of the spider gives a 42 mm chainline. Your problem is going to be that your schwinn will not be spaced 120 in the rear, maybe 126 or 130 or something else. so you'll play with spacers to get your chainline right. hope this helps.