Mid 50's Roadmaster. These were the years that Companies were phasing out balloon tires and going with the smaller 26x1.75 tires, even though the frames were still huge. Similar to what car companies were doing at the same time, using 14" wheels instead of 15". The sad part is that the "middleweight" status gives your bike a lower value than it's older, balloon tire models. Still collectible, and a good looking bike. I'd ballpark the value around $500