MAVIC 845 derailleur main image

By 1989 it was more than clear that MAVIC needed a replacement for the venerable MAVIC 801/851series. The Shimano Dura-Ace SIS (7400) had been launched in 1984, and index shifting was spreading through the pro peleton like wildfire. More importantly, Shimano was making index shifting available at lower price points, and consumers were starting to see it as the norm.

MAVIC's response was to create a Shimano Dura-Ace SIS (7402), but with French characteristics. The derailleurs were manufactured by Simplex, loosely based on their Simplex Vallée model, but MAVIC breathed on the detailing. The derailleurs were completely demountable, the finish on the castings was higher (if not to Shimano Dura-Ace standards), there were lots of, nicely machined, stainless steel small parts, bizarrely, the pulley wheels had needle roller bearings and finally there was the signature hard anodising of b-pivot bolt, parallelogram plates and pulley cage plates. Ah, and I almost forgot, they were also reassuringly expensive.

The styling was clean, simple, refined and modern, but it lacked the enticing eccentricity of MAVIC's earlier models. These derailleurs are quietly nice, but far from heart-stopping.

The MAVIC 840 series was offered with three different lengths of pulley cage:

  • The MAVIC 840 with a 46mm cage.
  • The MAVIC 841 with a 70mm cage 'for triple chainsets'.
  • And a later addition of the MAVIC 845 with a 75mm cage for 'mountain bikes'
  • Which brings me to the naming convention. Complete the number sequence: 800, 850, XXX. Does 840 spring to mind? Would 900 not seem more natural? How about if the 800 series was launched in 1979 for model year '80, and the 850 series was launched in 1984 for model year '85, what would you call a series launched in 1989 for model year '90? Does 840 spring to mind? Would 900 not seem more natural?

    And why is the short cage derailleur for double chainsets the 840, the longer cage model for triple chainsets 841, but the very long cage model for mountain bikes the 845? What is it about 842 that would be so wrong? Simplex were the masters of a confusing naming conventions - and MAVIC seem to have been infected with their disease.

The MAVIC 845 was the long pulley cage derailleur in the MAVIC 840 series. It was particularly dull because it had very conventional looking, steel, pulley cage plates that weighed a ton.

But at least it was jazzed up for those zany, hedonistic, bad-ass, mountain bike boys with a colourful sticker that celebrated MAVIC's involvement with the Paris-Dakar mountain bike race. Most excellent, dudes.

  • Derailleur brands: MAVIC, manufactured by Simplex
  • Themes: A riot of colour
  • Country: France
  • Date of introduction: 1990
  • Date of this example: unknown
  • Model no.: 845
  • Weight: 297g
  • Maximum cog: 32 teeth (Sutherland’s 6th edition)
  • Total capacity: 44 teeth (Sutherland’s 6th edition)
  • Pulley centre to centre: 75mm
  • Index compatibility: 8 speed
  • Chain width: 3/32”
  • Logic: top normal
  • B pivot: sprung
  • P pivot: sprung
  • Materials: aluminium including the adjustable cable outer stop and the hanger bolt, but with steel pulley cage plates

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