Top Tube Size
Made in Taiwan.
The fourth digit in the serial indicates year of production (1999 or 2000). X in the serial indicates production Month (E to L - May to Dec). Y in the serial indicates production Month (A to D - Jan to April).
Mirra 540 Air model abbreviation is MA, M54 or 54.
Bikes made in Taiwan usually had an 5-8 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.
HT˚ = Head Tube Angle, ST˚ = Seat Tube Angle, ST = Seat Tube Length to top, CS = Chain Stay Length, BB = Bottom Bracket Height, WB = Wheel Base Length, SO = Stand Over, W = Weight. All dimensions center-to-center unless otherwise noted. Dimensions provided in millimeters. Chainstay and Wheelbase dimensions given as minimum lengths. Maximum lengths are up to 20mm longer