Originally Posted by
illwafer
SN is: E5K7C84
E = TX500,
5 = 25.5",
K= November
7 = 1977
So, 1977 TX500 with Ishiwata 022. Strange how this was modded then. Lots of upgrades that probably occurred around 1983-4?
This is consistent with the SunTour GS dropouts as well. Mountech derailleurs were introduced at 1983, so I think you are correct about the timing of those upgrades