We reproduced track cog lockrings for the early Schwinn Paramount hubs. The lockring thread is unique and original lockring is increasing harder to find.$50
Reproduction Schwinn Paramount dropout adusters for sale
We recently had Schwinn Paramount dropout adjusters machined and cadmium plated, a faithful reproduction of original ones found on Paramount track bikes from the late 1930s-late1950s. Schwinn originally copied the design from quality British made adjusters, so they are interchangable with BSA, Chater Lea, and other British hubs of the time.They are $100 a set.
Via Bicycle 