Hello everyone. I got this frame locally and was told it was an older Schwinn but I am not sure. Any help in identifying would be nice. I am planning to make a vintage single speed but ran into a problem with the bottom bracket. This measures 71.5mm which is a weird size. It came as a bare frame so no info or parts to reference on it. I dont know how to proceed to take the next steps. Only thing I can think of is get a 73mm bottom bracket and somehow space out 1.5mm. .75mm from each side. any help would be appreciated.