
Originally Posted by
T-Mar
The SunTour Vx derailleurs were produced from 1977 to 1985. However, I believe the brand was still Italvega at the beginning of the timeframe, so it's likely early 1980s. Gut feel is 1983-1984. Miyata made many Univega and if this is one of them, I can narrow things down via the serial number. Alternately, you can start checking component date codes, but it sounds like a few things may have been swapped out.
The 27"/69cm frame was uncommon but not rare. Several manufacturers made them, but usually only in one model. That model was generally an entry level bicycle, about 2nd from the bottom of line. This was typically the best seller for most manufacturers and so they offered it in the largest size range. Examples from the early 1980s include the Centurion LeMans, Fuji Supreme, KHS Gran Sport, Lotus Excelle, Miyata 210, Panasonic Sport, Raleigh Olympian and Sekai Grandtour.