This Pop pin works with ALL Schwinn Johnny G Spinner Series bikes, ALL Star Trac Spinner series bikes. Exceptions: The “V” series bikes use their own type of pop pin and the NXT uses a different triangular shaped handle. If you have the original Schwinn Johnny G Spinner Pro with the black ball pop pin and you want a snug interface between the post and frame, this can be used to retro the black ball pop pin fitting.