Top Tube Size
Made in Taiwan.
Fourth Letter in the serial indicates year of production (1997 or 1998). X in the example above indicates production Month (E to L - May to Dec). Y in the example above indicates production Month (A to D - Jan to April).
Bikes made in Taiwan usually had an 8 month production and shipping timeline before they were sold in bike shops around the world. In May of any year, factories would usually switch production to making models for the following year.