Originally Posted by
unworthy1
did you scan this thread?:
http://www.bikeforums.net/showthread...jackson+serial
there might be something in there, including some iffy guesswork by yours truly. Too bad BJ doesn't seem to be offering the build cards for 25 pounds anymore (or so the rumors go), still if you ask nicely they might respond.
My guess it that it's a late 70s/early '80s frame, but the 'conservative' touches like the top-of-BB-cable guide can be misleading, I think BJ used those well past when others had moved on.
I checked the thread out, some good info for comparative analysis. It's hard to place a firm date,but I would agree sometime between 79 and 82 (mine is 12969). Some very fine looking BJ's in that thread. The geometry on my BJ looks to be a little tighter than some of the cycles on the thread. Race geometry maybe?
Thanks again for the info unwourthy1