Early 50s La Gazelle - Eau-de-Nil 🛠️ The Merlot Aftermath 🍷

[Mickeyspinn]

I think I could squeeze a 5 out of my 4 speed with a bit of jiggery. I think it's the main tension spring at the dropout pivot that's the issue....bit close to chain. I've got a 20 tooth up top think 23 -24 doable however I notice your dropout is quite different in where the derailleur pivot mounts! Which leads me to think yours is more likely a 5?! Maybe those axle placing thingamiggies give you the option of 4 or 5 depending wether they're in or off the bike?
Here's a pic of my dropout and mount placement.

You've got the luxe dropout....mines the here world here's the first four speed derailleur ...er we'll just weld the hanger onto existing dropout for now...

If your derailleur as it is feels free and the push rod isn't gritty or seized measure how much travel it has....I'll check it against mine ....that'll tell you instantly. The travel is preset not like modern derailleurs....it's all done on the pushrod.

 

[Mickeyspinn]

Simplex rear gear lever, down-tube mount. Again, model and date unknown.

Lever is a bit stiff, but it all appears it works as it should. What will I expect when I start to take it apart - just something straight forward with some friction bushes / washers or 3 million tiny ball bearings that will fall out?

View attachment 659971

You will find simplicity ...nothing more!
Probably about 5 or 6 bits.
Rear derailleur.... different matter

 

[Mickeyspinn]

Your chain!.....can't quite see.....is that a simplex chain .... phhwooaar

 

[Woz]

LAM Super Dural Course...
https://velobase.com/ViewComponent.aspx?ID=988012E7-A52C-4836-BF1A-E954616811BA&Enum=117&AbsPos=4

Excellent - cheers for this. Photo is helping to see how these puppies fix to the handle bars - just checked and these look exactly the same.

There is a slotted screw on the inside. Might need to do some grinding on a flat bladed screw driver.

Looks like the screw drives a wedge out to fix them to the bars. Going to be fun too see if it's a left handed thread or if I need to turn the other way.

 

[Woz]

Essential tool #1 - a magnifying glass. How the hell did they get so much text on such small objects is beyond me.

Bingo - got a positive identity of the chain. Sedis Yellorex - and the dates are lining up fellas

 

[vcballbat]

Tour de France was offered in two versions 3-4 speed ⅛ chain and 4-5 speed 3/32 just got to figure out whats the difference or just measure the chain.

 

[Woz]

Oooof. This research is actually driving me nuts. Top help there @vcballbat

From the Simplex catalogue 1953 - 1954.



From the Simplex catalogue 1955 - 1956. It says 20 tooth maximum capacity.




Note to other people - don't by an old French bike without wheels. Can't believe this is that complicated.

 

[Woz]

So, if I'm getting this right it looks like there is a Simplex Tour de France mech. on a Competition hanger, 24 teeth max sprocket, 20 teeth max capacity. Going to measure and compare that chain with 3/32" now.

 

[Mickeyspinn]

C'est simplex! What's the problem?
What's your dropout width...measure how much movement you've got on derailleur.....at least that will tell you how many cogs it had last...and chain....1/8 or 3/32.....process of elimination will give the answer

 

[Mickeyspinn]

How I see these little derailleurs is they're not a rando type gear set.....race close ratio.....your gonna have to muscle up lad.