Originally Posted by
roccobike
T-Mar, I'd like to add the seventh example. I picked up a 1986 Prestige. Dating is based on the date codes on both Suntour derailers (BK & CB). The serial number is WE16 259. WE16 is on top over 259 in the center of the BB casing. It's a little rough looking. I'd like to clean it up a bit, then I'll take pics and post.
The serial number seems a little strange, the 16,259th frame from 85 produced with a late 85 derailer and a early 86 derailer.
Well, at least it's another sample that contradicts the possibility of it being a month indicator. Even a week indicator would make it too early in 1985 to be a 1986. A fortnight indicator would put it into August, which makes a 1986 model possible, but still the frame would have to have hung around the factory for 1/2 year waiting for that derailleur.
The other consideration is that the serial number evidence indicates that some low end production had been moved to Giant , in Taiwan, as far back as 1980. We know this continued through 1985 and it would make sense that, over the intervening years, more models and volumes were sent to the more cost effective operations at Giant. It quite possbile that management forsaw the yen-shock of 1985 and had already offloaded much of the Nishiki production, leaving only the lower volume, high end and some mid-range models at Kawamura.
Or maybe my assumptions on the format is wrong. After all, it is only reverse engineering based on observation and analysis. It's meant to be a dynamic and is not cast in stone, though many members take it that way.