1999 GT Speed Series. U.S.A made XL Speedes 6061-T6 aluminum frame with Box chainstays. U.S.A. made Precision chain adjusters. New threadless full CrMo GT Stiletto fork with inverted GT Piston Stem. GT CNC'ed aluminum chainwheel. GT 3-piece aluminum crank with aluminum spindle and sealed-bearing BB. GT Rhythm System wheels. GT AA Pro tires. GT CrMo 4-piece pro handlebar. Dyno Lip grips.
Top Tube Size
Made in USA.
Third and fourth digits in the serial indicate year of production. 1998 or 1999. MM in the example above indicates production month
Bikes made in USA usually had an 4-6 month production and shipping timeline before they were sold in bike shops around the world. Bikes welded in the second half of the year would normally be made for the following year.
For more detail on what the serial number means on your mid school GT BMX, check out our easy-to-follow serial number guide.