1931 Harley Model C Single Frame

[therustyranch]

I am trying to find out what other years and possibly models frames interchange with a 1931 Model C. Any help, let me know if you have one for sale also.

Thanks Shawn

[Steve Slocombe]

Dear Shawn, it's the same frame as the 1930/31 D model small twin, and maybe later 1929, the years of the 'three cylinder Harley' with the vertical generator. For 1932 they brought out the new frame for the 750 cc bike with the bump at the front to clear the new Model 32E generaror lying across the motor. The early frame for the C model continued for 1933/4 until production of single cylinder bikes wound up. The 21 inch/350cc single and the VL Big Twin had different frames, as did the Servicar introduced in 1932. Johnny Sells' book on the 1929-36 small twins is packed with info on all except your engine.

[Fiskis]

Technically your 31C motor will fit in any 1926-34 Single frame as will a 21B and 29-31D motor do. The 1935 Parts Book offers the same replacement frame for 1930-34. I have not studied the 1932-34 frames but an enforcement is added for 1931 on the upper rear legs. As with the VL frames, there probably are some cosmetic changes through the production years.