DISRAELI GEARS

Huret Allvit (2500 early 1977 version)

The Huret Allvit was a milestone in derailleur history. It was the first parallelogram derailleur designed for the mass market. With its wacky parallelogram geometry and its pulley cage pivot concentric with the guide pulley, it made a real attempt to maintain an even chain gap and provide a decent change over 14 to 28 tooth freewheel.

In its various guises the Huret Allvit was the first French parallelogram derailleur and the first derailleur from any nation to break into the all important American market for leisure bicycles.

Despite this historic role, I always disliked it. It weighed a ton, its adjustment screws were all over the place and most of all it had too many small plates joined by too many dodgy pivot bolts. In British weather, maintained by oil-shy British cyclists, it either rapidly loosened off and became horribly imprecise or it rusted solid.

The Huret Allvit was one of the longest lasting derailleur designs in history. There is an untold number of different variants - certainly more than 30. These can, perhaps, be best understood by dividing them into 4 'eras', which are defined by the design of the main arm:

  • The first 'era' ran from 1958 to 1960. During this period the main arm was largely flat and the parallelogram mechanism was in full view. I have been told that these models had model numbers in the 1800s - although I have never seen this in print.
  • For the second 'era', from 1961 to 1967, the main plate was completely redesigned to become the Allvit's signature wrap-around body, encasing the paralelogram mechanism. The main plate had a flattish area around the head of the b-pivot bolt, but had a pointed reinforcing rib running down the rest of its length. These models had numbers in the 1900s.
  • 1968 to 1975 saw a third 'era'. The main arm was again redesigned, losing the reinforcing rib and gaining a triangular, almost heart-shaped logo. The model numbers were still in the 1900s.
  • The fourth 'era' ran from 1976 to 1983. I personally never saw many problems with the main arm, but in 1976 it was redesigned again, now with what could almost be described as buttresses around the head of the b-pivot bolt, and the return of the pointed reinforcing rib running down the rest of its length. Now the model numbers were initially in the 2500s and later in the 2700s. The last Allvits were probably produced in 1983.

So I hope that's clear then!

Focussing down onto the fourth 'era' some of the variants include:

  • 1976 saw yet another extensive redesign. The main arm now had what could almost be described as buttresses around the head of the b-pivot bolt. The pointed reinforcing rib running down the rest of its length made a welcome return. The parallelogram was also slightly redesigned. The 'décorée' versions, and their red pulley wheels, were consigned to the dustbin of history, and all models had an annoying plastic button at the b-pivot bolt.
  • The 1976 range included the standard Allvit (2500) for Huret ends, the standard Allvit (2540) for Campagnolo ends, the long cage Super Allvit (2548) for Huret ends, the Super Allvit (2554) for Campagnolo ends, the ridiculous Allvit Safety (2546) for Huret ends and the Allvit Safety (2549) for Campagnolo ends.
  • For 1977 the tension pulley was changed from a ballbearing item to a plastic object with plain bearings.
  • And so to the final change, in 1978. The parallelogram was changed from being screwed together (and demountable) to being totally rivetted (and not demountable). To celebrate this change (for the worse) Huret added the Roman numerals 'III' to the model names - indicating that Huret regarded these derailleurs as being the third of something - or, perhaps,as being as mad a King George III. As you might expect, Huret had never used the numerals 'I' or 'II' and this was clearly at least the fifth redesign of Allvit - so one can only shrug in a Jean-Paul Sartre kind of way.
  • The 1978 range was a masterpiece. It included the standard Allvit III (2700) with a rivetted on hanger plate, the standard Allvit III (2700 H) for Campagnolo ends, the long cage Super Allvit III (2748) with a rivetted on hanger plate, the Super Allvit III (2748 H) for Campagnolo ends, the clown-car Allvit Safety III (2746) with a rivetted on hanger plate and finally the Allvit Safety III (2546 H) for Campagnolo ends.
  • Mercifully, I believe that that may conclude the Allvit story.

This is a fairly tidy Huret Allvit (2500) from early 1977. Some of its attributes are:

  • The main arm had a hint of 'buttresses' around the head of the b-pivot bolt and a pointed reinforcing rib running down the rest of its length
  • The word 'Allvit' is stamped into the reinforcing rib. The word 'Huret' is stamped at the bottom of the main arm in a speckled oval.
  • The hanger plate is attached with a proper allen bolt at the b-pivot.
  • The parallelogram has removable, bolted pivots.
  • At the guide pulley, the leading tip of the outer parallelogram plate has a 'fold'.
  • The guide pulley is a full ball-bearing item with black plastic teeth. The tension pulley has teeth and a plain bearing.

  • Derailleur brands: Huret
  • Categories: Huret - the astoundingly complex Allvit & Luxe
  • Country: France
  • Date of introduction: 1977
  • Date of this example: Week 8 1977 (stamped 0877 on parallelogram plate)
  • Model no.: 2500
  • Weight: xxxg including hanger plate
  • Maximum cog: 30 teeth (source: Huret)
  • Total capacity: 34 teeth (source: Huret)
  • Pulley centre to centre: 50mm
  • Index compatibility: friction
  • Chain width: 3/32”
  • Logic: top normal
  • B pivot: unsprung
  • P pivot: sprung
  • Materials: largely steel with the inner parallelogram plate made of bronze?

Ref. 2263