mrg
Riding a '38 Autocycle Deluxe
Nos 17 in. quill seat post, I've tried it in a few brands of bikes pre/post war Schwinn, post war Columbia, AMF Roasmaster & Shelby and I'm sure others, looks close to 13/16 in. great if the og clamp doesn't hold like the red 41 shorty Schwinn frame and the damaged blue Snyder/Hawthorne ( it needed a shim ), $12 shipping, PayPal friends & family or cash on pickup LB/OC area.