To celebrate the 25th anniversary of the first Dura-Ace groupset, Shimano released a special commemorative groupset including this 9 speed derailleur. Note the subtle golden ‘25’ written to the left of the Dura-Ace logo.

Other differences were a titanium hanger bolt and cable clamp bolt, stainless steel pivot points and (for some reason) black pulleys with white writing on them.

• Derailleur brands: Shimano
• Categories: Shimano - the Dura-Ace story
• Country: Japan
• Date of introduction: 1998
• Date of this example: 1998? (no two letter date code)
• Model no.: 7700 SS
• Weight: 189g
• Maximum cog: 27 teeth
• Total capacity: 29 teeth
• Pulley centre to centre: 50mm
• Index compatibility: 9 speed
• Chain width: 3/32”
• Logic: top normal
• B pivot: sprung
• P pivot: sprung
• Materials: aluminium