Huret Allvit red (1900D 1968? version) derailleur

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 third 'era' some of the variants include:

1969 saw an extensive redesign. The rib was removed from the main arm and a larger, heart-shaped logo was introduced. There were possibly two models, 1900D (for décoré) and 1900. The décoré version had a printed logo and a plastic cap at the b-pivot bolt. The plain vanilla version had a stamped logo, with a randomly dotted background, and no plastic cap. The pulleys were Huret's signature steel, ball bearing pulley wheels with round plastic 'tyres'.
Sometime around 1970, both the Allvit 1900 and 1900D got the same new logo. This was the stamped heart-shaped design with a background that was a fine grid of lines.
1970 also saw a third version - the Allvit CS (1900CS). Aimed at the US market, this had a 'Cable Saver' - a sprung cable adjuster that operated in a way similar to the sprung cable clamp of the highly successful Shimano Lark and Shimano Eagle.
Perhaps in 1972, the guide pulley was changed from being round to having teeth
Also in 1972 Huret introduced the Super Allvit (1999) and (1999D). These had a long pulley cage and could handle a 34 tooth sprocket. Unlike the standard version they also had a toothed, ball bearing tension pulley.
Possibly in 1975, the pulley cage plates on the standard Allvit (1900) were lengthened to 50mm, and there were three 'struts' at the tension pulley. Also, the tension pulley was changed from a round, ball bearing item to a toothed pulley with a plain bearing.

This is a catastrophically batterted, but largely complete, 1968, Huret Allvit (1900D) with red logos and pulley wheels. I believe that it is missing the plastic button at the b-pivot bolt.

Some of its attributes are:

It has a wrap-around body that 'encases' the mechanism. It has a heart-shaped logo.
The, rather fine, gold on red logo is painted onto a thin plate stuck on the main body.
The spacer between the main body and the hanger plate is steel.
The pulley cage spring is trapped by a set of 2 hooks integrated into the outer pulley cage plate.
It has Huret's signature steel, ball bearing pulley wheels with round red plastic 'tyres'.

My memory is that these red versions were barely seen in the UK. Were they restricted to certain markets like the USA?