imcranco wrote:Can anyone tell me the proper frame for my 1957 motor (57xl1729) I've been told it should us a 1956 K frame by some and others say a 1957 XL frame. Supposedly the very '57s used the late K frames. I would love some in-put. I have a 56 and 57 frame
Over in the Technical section, there's an article called "Serial and Other Numbers" - it has info about frame date codes. Your bike was #729 of 1988 produced. Some guesswork about monthly production puts it around January 1957. The frame was probably made 1-2 months earlier, maybe November or December 1956. So your frame date code might be K6 or L6.
We don't know how many bikes the factory rolled out each month, nor do we know exactly how far in advance the frames were made. So maybe the bike shipped in February, the frame made in January (A7). It's all guesswork. What's important is that it is reasonable - obviously the frame could not have been made after the bike shipped. Nor should the frame have been made 9 months prior.
What are the date codes on your frame?