Groupset · 1988–mid-1990s

Shimano 600 / 600 Ultegra (6400)

The 6400 series was Shimano's second-tier road group of the late 1980s and early 1990s. Wikipedia's list of Shimano groups dates the 6400 group to 1988 as a 7-speed SIS group nicknamed "Tricolor", followed by the 8-speed 6402 with STI levers in 1992 and the 9-speed Ultegra 6500 in 1997. Sheldon Brown explains the naming that confuses listings: the Ultegra name was added as a suffix to 600 in the early 1990s, and "600" was dropped in the 1998 model year. Earlier 600 groups, like the 600 EX, came before this. For compatibility, 6400 parts use the standard Shimano road cable pull, so they index with other non-Dura-Ace SIS parts of the same speed count but not with Dura-Ace 7400 levers or derailleurs. Cranks use 130 mm chainrings, and Sheldon Brown lists the bottom bracket spindle at 113 mm. Calipers from the 1988 launch are single-pivot, since Shimano's dual-pivot brakes came in the 1990s.

4 references tracked in the gruppo.