With the Crane, Shimano pulled out all the stops in an attempt to make a truly world-class derailleur. It was an all aluminium design with a dropped parallelogram - a world first. The finish was excellent with that anodised ‘glow’ that Campagnolo had perfected. The chromed parts were bright and polished.  The pulleys had a two part bushing system so that bronze rotated on bronze. Even the springs seemed to have less of a tendency to lose their tension. All very classy.

Shimano were not backward in coming forward with the price - which set new records for a Japanese derailleur (even if it was still someway from Campagnolo’s extravagant pricing).

The only fly in the ointment was SunTour’s patent on the slant parallelogram. The Crane never changed gear quite as well as the much more lowly SunTour V series - despite Shimano’s puff about the efficacy of their ‘servo pantagraph’ design with its two sprung pivots.

This is a handsome black example of the fourth generation of Crane with Dura-Ace-(7100)-style hollow Allen bolts with plastic seals at the two main pivots. This, seemingly small, improvement saves 23g.

This example also has the extremely smooth-running steel pulley wheels that I noted on the Shimano Crane (DB-100 1st style) in this collection.

____________________________________________

1. •Brand: Shimano
   

2. •My category: Shimano - the Dura-Ace story
   

3. •Country: Japan
   

4. •Date of introduction: 1977?
   

5. •Date of this example: unknown (no two letter date code)
   

6. •Model no: DB-100
   

7. •Weight: 230g
   

8. •Maximum cog: 28 teeth (Sutherland’s 4th edition)
   

9. •Total capacity: 28 teeth (Sutherland’s 4th edition)
   

10. •Pulley centre to centre: 46mm
    

11. •Index compatibility: friction
    

12. •Chain width: 3/32”
    

13. •Logic: top normal
    

14. •Pivots: two sprung pivots
    

15. •Material: aluminium, with steel pulley wheels
    

0108/D