And here it is... Shimano’s very first mountain bike derailleur. This first version of the Shimano Deore XT (M700) is a subtle blend of the Shimano Deore (DE20) - see that Centeron lever - and the Shimano New 600 EX (6207 GS) - with its clean, uncluttered lines and straight-forward pulley cage.

The Deore XT (M700) appeared a year later than the SunTour MounTech - but still ran off with the mountain bike crown because of what it lacked - complexity. Shimano claim all sorts of stuff about improved seals on the sprung pivots and other off-road refinements - but I am never quite sure about the reality of this. Mainly the Deore XT (M700 1st style) was a well-made, simple, strong gear, that had the good luck to appear just when the market was looking for a well-made, simple, strong gear. But then, luck is what happens when preparation meets opportunity.

Personally I liked the New 600 EX better - that Deer Head logo still seems too hunting-lodge-kitsch - you can almost hear the skirl of the pipes and feel the itch of Harris Tweed against your skin - or perhaps Woody Allen might shoot you and strap you to his car fender... But I did appreciate that the adjustable cable outer stop and the Centeron lever were handy features when using the long cables that thumbshifters required.

A milestone in derailleur history.

• Derailleur brands: Shimano
• Categories: Shimano - the Deore XT story
• Country: Japan
• Date of introduction: 1983
• Date of this example: 1983 (two letter date code is HH on the pulley cage plate)
• Model no.: M700
• Weight: 236g
• Maximum cog: 34 teeth (Sutherland’s 6th edition)
• Total capacity: 40 teeth (Sutherland’s 6th edition)
• Pulley centre to centre: 85mm
• Index compatibility: friction
• Chain width: 3/32”
• Logic: top normal
• B pivot: sprung
• P pivot: sprung
• Materials: aluminium with a steel Centeron lever and inner pulley cage plate

Ref. 86