For me, the Shimano New 600 EX was another turning point on Shimano’s road to world domination. Despite its lack of a slant parallelogram, it was the first Shimano derailleur that I liked better than its SunTour equivalents (the clunky SunTour aRX, the beautiful super-light but fragile Cyclone II and, later, the gross Cyclone 6000 series). After all the nonsense of Positron and Aero AX, Shimano had gone back to basics and played a blinder.

The New 600 EX was solidly constructed and very nicely finished, but most of all it had a very clean, elegant ‘engineered’ look. This is hard to appreciate today - because a great many derailleurs over the last 25 years have imitated this look - but that is part of what makes a classic.

Another fine feature of the whole New 600 EX gear set was its use of 6mm Allen key bolts throughout. One Allen key for everything - now there’s a thought.

Finally, just as the ‘real’ first mountain bike derailleur was the SunTour V GT that Gary Fisher fitted to his clunker, so the ‘real’ daddy of the Shimano mountain bike line was the GS version of the New 600 EX. Not only did the Deore XT line (after a few false starts) adopt its look, geometry and pulley cage design, but also, in the early days, many mountain bikers adopted the New 600 EX as their derailleur of choice.

• Derailleur brands: Shimano
• Categories: Shimano - the Ultegra story, Shimano - the Deore XT story
• Country: Japan
• Date of introduction: 1982
• Date of this example: 1984 (two letter date code is IF)
• Model no.: 6207 GS
• Weight: 221g
• Maximum cog: 34 teeth
• Total capacity: 34 teeth
• Pulley centre to centre: 75mm
• Index compatibility: friction
• Chain width: 3/32”
• Logic: top normal
• B pivot: sprung
• P pivot: sprung
• Materials: largely aluminium, steel inner pulley cage plate