Schwinn 24 bike Frame Middleweight Cantilever Bicycle vintage pre 63 Lowrider

  
Frame as shown fits 24 wheel set. Serial number single letter "K" indicating pre 63? These 24's can be fitted with a 26 wheel set if you grind the rear drop out some and install the rear wheel with the tire and tube deflated.

It's kinda sorta like a donked out bike in a way and I have done it! The ride is smooth with a bent 26 fork set up.