Shimano Dura-Ace black (7100)

Shimano Dura-Ace black derailleur (7100) main image

Following their experiences supplying the Shimano Crane to a European pro racing team Shimano became convinced that the key to success at pro level was a combination of sophistication and durability. They wanted to combine the indestructability of the Campagnolo Nuovo Record with (whisper it quietly) the sophistication of the SunTour Cyclone and Superbe.

The result was this derailleur - the Shimano Dura-Ace (7100). It is a heady cocktail of 3mm and 6mm allen bolts (even the adjustment screws) and cold forged aluminium. The pulley wheels have two part bronze bushings, like Campagnolo, and, in a curious echo of the Sanko-sha Procyon, it incorporated a ‘Synchro-Line Mechanism’ whereby the cable outer stop and the cable clamp bolts were kept aligned by a pin through the each of the relevant pivots.

I am rather fond of this rear mech, it is sophisticated without being complex and, to this day, it remains Shimano’s only real attempt at making a truly lightweight derailleur. This black example is particularly stylish.

  • Derailleur brands: Shimano
  • Categories: Shimano - the Dura-Ace story
  • Country: Japan
  • Date of introduction: 1977
  • Date of this example: 1977 (two letter date code BI, stamped on the pulley cage plate)
  • Model no.: 7100 or DA-100
  • Weight: 175g
  • Maximum cog: 26 teeth (Sutherland’s 4th edition)
  • Total capacity: 26 teeth (Sutherland’s 4th edition)
  • Pulley centre to centre: 46mm
  • Index compatibility: friction
  • Chain width: 3/32”
  • Logic: top normal
  • B pivot: sprung
  • P pivot: sprung
  • Materials: aluminium

Browse associated documents.

Shimano Bicycle System Components (12/1978)

Shimano Bicycle System Components (12/1978)

  • Publisher: Shimano
  • Date: December 1978
  • Derailleur brands: Shimano
  • Derailleurs: too numerous to list here
Shimano Bicycle System Components (December 1978) front cover thumbnail