The 1987 GT Pro Series Team. The team model is the same bike used by GT Factory Racers. Its been designed with rider input to be the ultimate race bike, and its choice components include GT Power Series™ Cranks, GT Sealed Bearing Hubs, DK Stem, IRC Tires and Dia-Compe 901 Brakes front and rear. Colors: Black White. Chrome, and GT Blue
Headset Size
1"
Seatpost Size
22.2
Top Tube Size
Unknown
Original Colours
XX860000 XX870000
Made in USA.
The XX in the example above indicates production month. The third and fourth characters in the serial indicates year of production. 1986 or 1987.
Bikes made in Overseas usually had an 3-6 month production and shipping timeline before they were sold in bike shops around the world. Bikes welded in the later months of the year would normally be made for the following year.