What are the actual sizes? The only time Trek actually list the frame size in the catalog is in 1995.
Some of the early bikes had a size sticker on the frame also with the measurement. From 1996 onwards, the bikes were simply listed as S,M, or L, although the size stickers continued on the actual frame for a short time.
Note that the above Trek measurement is from the crank centre to the top of the top tube. Most people measure from crank centre to top of the seat post clamp, so the above sizes are then slightly larger. Trek must have realised this, for in the 1997 Retail Technical Manual they have changed their method of measuring to the top of the seat post clamp, which they call "seat tube length". Now the sizes are: