The days of USA made bikes

Check out this rad video I found, it shows most of the steps in building mass produced bicycles.

I like the movie because it shows them making the tubing in house - this was very common, up until the late 1970s for Schwinn and Columbia. The very large roll of thin flat strips of steel shows up at the factory on train cars and the tubing mill rolls the steel strip in to a tubing shapes. The last step of the mill is to weld the seam of the steel strips closed, making a sealed tube. Some machines even finish the tube by grinding it.

The other machines shown in the first part of the movie are Swiss screw machines. The machine is the fastest machine in the machining world for mass produced machined parts. It runs on cams and gears and uses raw force to drill, cut and profile the parts. The operators had to understand how to adjust the machines by using a large series of gears, cams and belts. The cutting tools used have to be made to the outside shape and contours of the parts as the machine only travels on one axis when cutting, so it could only make one cut to make the outside shape of the part.

Check out the video for all the cool machines