From 1984 to 1996 Shimano's top two road groups were Dura-Ace 7400 and the mid-level 600, which picked up the Ultegra name along the way. On eBay the two lines are listed under a confusing mix of names: 600, 600 EX, "Tricolor", 600 Ultegra, Ultegra 6400, Dura-Ace 7400, 7402, 7403. This guide sorts out the names, the sub-series and the brake designs, and explains the one compatibility rule that catches most buyers: old Dura-Ace rear derailleurs index differently from every other Shimano road derailleur of the period.
How 600 became Ultegra
The 600 name goes back to the mid-1970s. In rough order, the generations you will see are:
- 600 (6100 series), mid-1970s to early 1980s, friction shifting.
- 600 EX "Arabesque" (6200 series) from 1978, named for the swirling pattern engraved on its parts.
- 600 AX (6300 series), an early-1980s aerodynamic detour.
- New 600 EX (6207), a cleaner friction design from the early-to-mid 1980s, followed by the RD-6208, marked "Shimano 600 SIS", the first indexed 600 rear derailleur, from about 1986.
- The 6400 series from 1988. The parts are marked "Shimano 600", with a three-colour band on the rear derailleur's outer plate and the crank arm. That band is where the "Tricolor" nickname comes from.
Sheldon Brown's notes record that the Ultegra name was added to 600 in the early 1990s, and that the "600" designation was dropped when Ultegra went to 9-speed for the 1998 model year with the 6500 series. In practice, "600 Tricolor", "600 Ultegra" and "Ultegra 6400" describe the same family. The model number stamped on the part tells you more than any of those names. Within the family, the RD-6400 is the late-1980s 7-speed derailleur, and the RD-6401 is its 8-speed successor from the early-to-mid 1990s, with a revised pulley cage.
Dura-Ace 7400 and its sub-series
Dura-Ace 7400 arrived in 1984 with SIS, the first indexed shifting system to work reliably. Disraeli Gears identifies five versions of the rear derailleur:
- 7400, 1984: 6-speed, no b-tension screw, a 6 mm Allen cable clamp and bronze-bushed pulleys.
- 7400, 1985: still 6-speed, with a b-screw and pivot seal added and a revised pulley cage.
- 7401, 1986: 7-speed, with the outer cage plate labelled "6S-7S SIS".
- 7402, from 1988, in two styles: a broad redesign for 8-speed with a plastic shield on the b-pivot, a concealed p-pivot, a clicking cable adjuster, a 5 mm cable clamp, a spring-tension dial and "Integrated 8 SIS" on the cage. Disraeli Gears has a 7402 dated 1996, so the design stayed in production until the end of the series.
Sheldon Brown's timeline adds the 7403 designation: 8-speed Hyperglide and Superglide chainrings around 1990, then STI brake-shift levers and dual-pivot brakes in 1991. Shimano parts usually carry a two-letter date code, with the first letter for the year and the second for the month. Our dating guide has the key. The 7402 parts in this catalog are the RD-7402 rear derailleur, the FD-7402 front derailleur, SL-7402 down-tube levers and the FC-7402 crankset.
Single-pivot or dual-pivot brakes
Model numbers are the only reliable guide here, and eBay titles often get them wrong. According to Velobase:
- The BR-7400 and the BR-7402 are single-pivot calipers.
- The BR-7403, marked "SLR-S" and made from about 1991 to 1996, was the first dual-pivot Dura-Ace brake.
- The BR-6400 is a single-pivot SLR caliper from 1988 to 1990, replaced by the dual-pivot BR-6403 from 1991.
- All four are listed with 39–49 mm reach, so check your frame before assuming they will fit a 1970s bike built around longer-reach brakes.
Sheldon Brown sums up the trade-off: dual-pivots are easier to keep centred and can have more mechanical advantage, but they track a slightly out-of-true rim less well than single-pivots.
What mixes and what does not
The key rule comes from Sheldon Brown's Dura-Ace compatibility article. Pre-1997 Dura-Ace rear derailleurs move a shorter distance of cable per shift than the 600 EX SIS derailleur and everything that followed it. In practice:
- A 7400-series rear derailleur indexes with 7400-series shifters set for the right number of cogs.
- A 600, 6400 or other non-Dura-Ace SIS rear derailleur indexes with non-Dura-Ace shifters.
- Dura-Ace 6-, 7- and 8-speed rear derailleurs are interchangeable with one another, and so are the non-Dura-Ace ones.
- An old Dura-Ace lever can drive a non-Dura-Ace derailleur through an alternate cable routing at the clamp bolt.
Cassettes are less fussy. Shimano cassettes with the same number of cogs use the same spacing whether or not they are Dura-Ace. The exception is the Uniglide era, which ran through 1989: the threaded smallest cog on Dura-Ace Uniglide used a smaller thread so it could carry an 11-tooth top. 8-speed Uniglide was made only for the 1989 model year, so it is scarce. Hyperglide, with all cogs splined and a lockring, followed in 1990. Dura-Ace freehub bodies up to 1996 thread into the hub shell and don't interchange with other Shimano hubs, though the 6-, 7- and 8-speed Dura-Ace bodies interchange with each other. Rear spacing is generally 126 mm for 6- and 7-speed road hubs and 130 mm for 8-speed.
The cranks are close cousins. The FC-7400, FC-7402 and FC-6400 all use a 130 mm bolt circle and a JIS square taper, but Velobase lists different recommended bottom bracket lengths for the Dura-Ace and 6400 cranks, so match the spindle to the crank. Shimano's Superglide chainrings were designed as matched pairs, and Sheldon Brown notes that mixing them still works, just a little less smoothly.
Choosing between them
If you are restoring a bike, match what it came with. The model numbers on the original parts tell you which generation that was. If you are building a bike to ride, the practical question is the shifter. Decide between Dura-Ace and 600 first, then buy the rear derailleur from the same family, and confirm 126 or 130 mm spacing before you buy wheels. For hub and threading questions across brands, see the compatibility guide.
Before you bid
- Read the model number on the part rather than the title: RD-7400, 7401, 7402; RD-6208, 6400, 6401; BR-7402 or 7403; BR-6400 or 6403.
- Ask for the date code if originality matters.
- Confirm that the derailleur and shifter are from the same indexing family.
- Check rear derailleur pulley wear and pivot play, and on brakes look for seized pivots and missing hardware. The inspection checklist covers the rest.
