Technical evolutions of the VéloSoleX : a chronology

In this panorama I will detail in particular the evolution of the "real" Solex, i.e. a bicycle with an auxiliary engine equipped with a special roller transmission on the front wheel. This means that this panorama will not take into account the Micron, the Flash, the 6000 and the Ténor.

In order to obtain a good quality product, Solex decided in 1940 to create a prototype which will lead in 1942 to the production of some units that will be tried out by the employees. Here are the characteristics of this pre-fabrication model :

  • it is a bike with an open frame made of a curved tube
  • the wheels are of 650
  • the front brakes have blocks and rear brakes have drums
  • the engine is 45 cc
  • the roller transmission uses a runner
  • the crank head is overhung on the crankshaft
  • the cylinder is out of the line of the wheel
  • the carburetor functions through a pump with a membrane, which is activated by the pressions and depressions in the crankcase
  • the gas overflow is drawn back to the tank
  • the front light is on top of the engine and the taillight is placed under the luggage rack.

The prototype will be perfected, and this will allow in April 1946 the mass production and commercialisation of the first Vélosolex. This '46 model has the following characteristics:

  • it's a 45cc of 0.4cv, at 2,000 rounds/minute
  • a lever at the right thumb serves as a moderator and decompressor. It was added to the experimental model
  • to switch between bicycle mode and moped mode, the carburetor top must be pulled up until the "click" of the bolt. To put it back in moped mode you only have to unlock the bolt placed on an articulated plate
  • the black frame is unisex
  • the wheels are 650
  • the handlebar is chromed
  • the brake handles are inverted
  • the black light is on top of the magnetic wheel
  • the bottom of the rear mudguard is painted in white, in order to conform to the road regulations
  • the crankcase of the chain is made of steel
  • the luggage rack is made of wire and has a tool kit in the front and a pump on the right
  • the seat is suspended on three springs
  • the one-liter tank allows to drive for 100 kms at 25 km/hour, and the cap is used to measure the oil in the gas mix.
  • the whole bike weighs 25 kgs

In 1946, new changes will be made, and more particularly the rear fork and its riggings are no longer welded but bolted to allow easier repairs. In 1948 the tool kit is moved to the end of the luggage rack, and a reflector is added to the rear mudguard to replace the white painted line.

In 1951 a new model appears. Here are the characteristics that differentiate it from the former model :

  • a clutch/pull up lever is tightened on the cylinder head and held by a hook located on the stem of the handlebar.
  • a steel cap hides the gas pump
  • a center stand holds the bike by itself
  • a net that protects skirts is installed between the rear fork and the mudguard; this device had been installed on the 1942 models but was left out during production
  • wheels are reduced to 600, which reduces the overall size by 8 cm

In 1951, the brakes are equipped with large rowels to adjust them, and those can be moved by hand. The rounded rims become flat.

The october 1953 model is the first one with a name, or actually a number: it is called "type 330." This new model offers particularly modifications on the engine:

  • the cubic capacity is 49 cc
  • the horse power is 0.5 cv
  • the torque is improved, which improves the performances uphill
  • the spark plug is tightened aslant on the front of the cylinder head
  • the air filter cap is fixed on the cylinder head and hides the decompressor
  • the driver is protected from gas leaks by a vertical metal sheet
  • the seat is articulated by its peak and suspended by two springs
  • the shape of the 330 exhaust pipe follows the fixation rod of the mudguard

In 1954, they'll make a second of the 330 with a luggage rack made of pressed steel sheet

The september 1955 model, called the 660, is mainly modified on the bicycle:

  • the frame tube stops at the pedals and is extended by the rear fork. The right arm of the rear fork is used as crankcase for the chain, and the whole thing is covered with bent steel sheet; this case covers the central stand, the crank gear, the platform of the foot rest, the rigging of the rear fork and the seat
  • the light is part of the plastic cap that covers the engine and is centered above the front wheel
  • two ribs are added to stiffen the tank and the cap of the magnetic wheel

In april 1957 the 1010 appears with modifications on the engine:

  • a new cylinder with a U sweep
  • a new piston with a slightly curved cap
  • a hemispheric cylinder head
  • a new exhaust with an S-shaped tube and a muffler fixed on the wheel hub
  • a new air filter, with more capacity and oval to cover the cylinder head

In september 1958 the 1400 appears with only slight modifications: smaller wheels (550), thicker tires.

In october 1959 the 1700 comes out with:

  • an automatic compound clutch
  • the cooling system of the engine that functions with a turbine coupled with the magnetic wheel

In June 1961 the 2200 will come out. Here are the main changes:

  • it has a spark plug tightened on top of the cylinder head
  • it is covered by the case of the air filter, painted in black and adorned with the sign S2200
  • its horse power is 0.7 cv

In October, 1964 the 3300 comes out. The changes are on the bicycle part:

  • the frame is rectangular, made of sheet metal
  • the seat is larger and suspended by only one spring
  • it now comes with a rear drum brake
  • a squared front light on top of a 2200 engine

The 3800 comes out in May, 1966 :

  • it has a better torque to improve its performances uphill
  • first color appears with the name in white letters on a red band, on top of the air filter cap

In 1968, the 3800 will still pioneer color: the whole cycle will be introduced in blue or red, with white rims ; and in 1969 they'll add steel mudguard. Those are the "luxury" models.

When Motobécane buys out the company in 1974, the 3800 will be modified with :

  • a new, larger light set on the back in 1977
  • straight brakes in 1986
  • reflectors are installed on the front and rear forks in 1986

You'll also find a pictures of a splited engine of 3800.

The 5000 is introduced in 1971 and will be sold at the same time as the 3800. It is the first time that the launch of a model doesn't imply the replacement of the former model. This 5000, which is available in 4 colors (yellow, orange, blue lagoon, off-white) has the following caracteristics :

  • smaller wheels (2*16 inches) with white-rimmed tires
  • the mudguards are made of stainless steel
  • the handlebar with elevated handles is the same as the Micron
  • the light is installed at the center of the handlebar support
  • the luggage rack is modified with profiled elements and ends with a plastic buffer
  • the toolbox is under the seat
  • the engine mount is replaced by a mecanism with a rod and a crank fixed to the fork

In 1973, this model is offered in a foldable version called "Plisolex." It can be folded at the basis of the central support by tilting the seat and the handlebar and by untightening the engine.

And a special thanks to Anne-Sophie who realy helped me translate this page (to mail her)

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