1966s non matching number of frame and engine

[gg]

hi there,
I just want to ask anybody who could help me clarify my case.I just bought a 1966 r 69s with engine number 660752,the bmw tag on the frame has matching number as in the engine(660752) however the frame number is 641490. my understanding is that usually r 69s always has matching numbers of frame and engine.My question is that is there any possibility the bmw factory made different number of engine and frame?I raise the question because the previous owner argues that the bike is not a mixture of r 69s engine with different frame.I also try to find out, if the frame does not come from r 69s production can anybody tell me which model is the frame?(641490)
gg

[Kurt in S.A.]

gg -

You've probably already got this figured out. But the 50s and 60s bikes all had matching engines and frames. The frame in question came from an R50/2. See this page for a breakdown in the VINs prior to 1970.



Kurt in S.A.