Thursday, September 30, 2010

Simplex Tour de France.

As many of you that have read my previous postings will know I have a keen interest in the history of derailleur gears and have accumulated a sizeable collection.

It has been suggested that I write a little about interesting models on a regular basis. This I will try to do in the hope that some of you will also find the subject interesting.

My first derailleur was an early French Simplex Tour de France model which I fitted to my Raleigh Lenton Sports in place of its original Sturmey Archer four speed hub gear. The Simplex was a three speed and had a much closer range of ratios than the Sturmey but it was a derailleur and that is what all the racing men used.

An early Simplex "Tour de France" model.

The Simplex Tour de France was the most popular racing derailleur in the period following the second World War. It was used by many of the top riders of the day including the Tour de France winners Robic in 1947, Coppi in 1949 and Kubler in 1950.

<Ferdi Kubler wins the 1950 Tour using a Simplex TdF derailleur.

A 1950 TdeF with it's wonderful presentation box.

An exploded view of the TdeF derailleur.

Like most derailleurs in the forties and fifties The Tour de France is a "push rod" design. The derailing cage with it's pulleys is attached to the end of a telescoping shaft. The cable is attached to the other end of the shaft by means of a toggle chain. Pulling the cable pulls the derailing cage to the next smaller sprocket. When the cable is released a large coil spring pushes the cage back. This central coil spring also applies tension to the chain.

The big advantage that the Simplex had over it's rivals was a second chain tensioning spring and pivot at the upper end of the main arm. This spring loaded pivot ensures that the upper pulley remains close to the sprockets irrespective of sprocket size. The close coupling of pulley and sprocket ensures crisp gear changes.

There is a nut at the end of the shaft that holds the whole mechanism together. It was not unknown for this nut to come off the shaft whereupon the spring shot a multitude of parts across the road much to the despair of the rider and the hilarity of his riding companions.

The patented "two sprung pivots" design was peculiar to Simplex from its introduction in 1946 TdeF model right through the Simplex range until the company's demise in the late eighties. Now all derailleurs use this design.

Fausto Coppi on his Simplex TdeF equipped Bianchi. 1949.

During their hey-day Simplex had factories in Italy and Germany. No doubt Coppi used Italian made Simplex which were somewhat better finished than those made in the parent factory in Dijon.

The Simplex Tour de France model was made in four types: three speed and four speed for 1/8" chain and four speed and five speed for 3/32" chain.

For it's time the Simplex Tour de France was a relatively reliable and efficient mechanism. The UK distributer described it in their advertisements as: "The gear with guts and glamour".


fred said...

Absolutely fascinating stuff. My first entry into dérailleurs was on a Raleigh Rocket, with Simplex dérailleurs. They remain oddly unique in design, albeit others must have used the chain link too from that era, Sturmey Archer obviously using it successfully for generations with their internal hub.

I'd almost forgotten all about that model. Many thanks Mike for jogging the memory.

Any more on dérailleurs much appreciated by me. Hurets and Mavics also of much interest, as well as the obvious Italian ones.

It has been noted by more than a few non-cyclomanics as to how much engineering you get in a rear-dérailleurfor a very modest price. Of course, the Japanese really promoted that aspect, but still, in the last few decades, some amazingly good European ones also available for very little cost.

The function a good dérailleur performs comes close to being exquisite, both in geometry and actual performance.

A topic that fascinates me also.

fred said...

No function to edit that I'm aware of, so I must correct my previous post.

It was a Raleigh "Blue Streak" not "Rocket".

The Blue Streak was the UK's first military missile, designed to delivered a nuclear payload. Ironically, it was cancelled in 1960, the year Raleigh brought out their namesake machine.

Pictures of both Mike's Lenton and the Blue Streak are here:

Joseph said...

Excellent topic. I was plonking around the interwebs, and thought I weuld see what's going on at Mariposa. I didn't know you had retired. I hope you're enjoying it, and I hope you continue this series.

Lluis Ciclista said...

Unknown said...

Hello! Fantastic article!!
Can anyone advise me on how I might purchase a 5-speed Simplex TDF?

-- BlackRockJohnny (not my real name)