non-fixie 

Yes, there's room for mudguards and yes, both brakes that were on the bike (LAM demi-ballon in the rear) do have a long reach, like 85-90 mms.

Some other thoughts:

I've looked at other frames with this Simplex shifter mount, and seen similar damage on some of them. Seems like it may well be the result of chafing from the shift lever (and rusting as a result of the metal being bare) so the mount may be original after all.



The vertical brake bolt in the rear brake bridge indicates it was probably made with mudguards in mind, right?



Also, double eyelets on the fork ends point in the same direction:

S28546

Vertical brake bolt and double eyelets is pretty clear it was intended to be fendered and is not a converted race bike.

Aubergine 

I am far from the most knowledgeable person here for old French bikes, but here in France I have seen many 650b bikes with 3 to 5 speeds. Peugeot, as should be obvious from the picture, had the Helium sub-brand. So, it seems to me quite likely that the bike was originally set up with the 650b wheels and a 5 speed (or less).



Hope that offers some minor help.

Millstone

Nice find, load of work, interesting/vague background...


Yeah, I'm intrigued!

non-fixie 

Yes, that and the rather long wheelbase.

Thanks. Yes, I've run into those. Both with 650B and with 700C wheels. The latter were possibly export versions, as 28" was the standard size in my area. And it leaves me wondering if there's actually a difference in the frames. As long as you use caliper brakes and a slotted generator mount you can go both ways, it seems.

Nice Helium, BTW.

.

Thanks. Well that vagueness is one of the main reasons I bought this and many of my other bikes. I like the detective work involved in finding out what is what. And watching the collective knowledge on this forum do its magic.

Munny

Hi Non-Fixie,

I'd like to ask you how the LeSimplex shifter looks
See my picture


This because it would help dating your rusty french bike
From the equipment that looks period
So far it looks post wwII to me but this may help to narrow the period

Good for you, now you can find 650B tyres at D4 shops, at a very low price. Unless you want to spend for names.

The picture is from an intriging Belgian randonneur that I bought in last quarter (Too many new bikes and no time)
The shifter with the S is more recent than with "Le Simplex made in france" and that S marked shifter is already visible on a 1949 Simplex catalog visible on DisraelliGears
I assumed my randonneur being older than that.

non-fixie 

Thanks, @Munny. It's the one with the "S":



This seems to jibe well with my guesstimating the frame to be from the late forties or early fifties.

What are those D4 shops that you speak of? Can't seem to find them. The demi-ballons that I did find online are €9 a pop, so those won't be a problem. However, the wheels that came with the bike are a mixed bag. The front looks like it could be original, but the rear is a replacement, I think. Both have steel rims, unfortunately.

You do realize you will now have to show us the rest of that randonneur, don't you?

non-fixie 

I removed the BB tonight. It came out quite easily, together with a handful of French soil.



No markings to indicate a manufacturer, alas. At first glance it looked OK, but not all is well:

noglider 

I have a cottered spindle. You want me to measure it?

Munny

How are they called again? Not Triathlon, not Pentathlon... ?
You also have them in NL

French BB?

non-fixie 

Ah, Decathlon. Lousy web shop, but cheap tires indeed. However, at 490g a piece for the B'Twin 650B, there's probably no room for an inner tube. Great for testing purposes, or a beater, but for a "nice" bike I'd be looking for something weighing half that.

Yes, the BB is French.

And I still need to establish the correct seat post size. The one that came with the bike is somewhat oval, and measures between 25.6 and 26.6 millimeters, so I'm expecting something like 26.4 to work. I need to go through my stash and see if I have one to confirm that.

non-fixie 

Thanks for the offer, Tom. Much appreciated. But I don't think it will be necessary. I'm sure I have a nice replacement in my stash. Somewhere ...

juvela

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Fittings appear too late for cycle.

Had same thought for chainset in first images.

Lends support to the idea that machine originally came with single plateau gearing.

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non-fixie 

My guess is that chainset and derailleurs were replaced at the same time time, somewhere in the seventies, or maybe even early eighties. You may well be right on the single plateau gearing. Removing more of that black paint may confirm that.

What would be your estimate of the velo's birth date?

juvela

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No guesses as to birthday.

When you get me back prior to 1959 am in terra incognita.

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mountaindave 

subscribed.

Munny

My dear

When you are looking at these fat tyres, expensive rubber is not lighter.
It is the large quantity of rubber that makes the impressive weight
That one at 9 € = 490g
A swalbe HS159, same price, is ... 580g
A WTB Horizon TCS 650B is lighter than the schwalbe at 515g but ... 5 times the price

Would you want to increase the assets of a know commercial company promoting old 650b, well well ... I see a "Compass 650B x 48 Switchback Hill TC" saving you a mere ...12g and so expensive.

The Japanese groote bos are in the same weight range and same expensive ...

I run these Btwin on a bike and besides the weight, my problem is that they are a bit loose on damp ground

Concerning the front derailleur, you also miss the chain guard and the combine scuicide chainguard derailleur would complement this bike

See you at the ronde

juvela

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One additional contradiction noticed -

While both of the cycle's wheels are clearly solid axle the axle slots in the frame ends look to be more than ample to accept a ten mm hollow axle -





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non-fixie 

Thanks, you've obviously already done my homework for me.

I will admit that I'm a little disappointed. Based on my experience with 700c Paselas, I'd expected to find something in the 300-400g range. Will keep the 700C option in mind.

Absolutely!

non-fixie 

Indeed. I hadn't realized, but I unknowingly confirmed that already in post # 22.

juvela

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the frame's chainstay gear hanger looks like it may be Cyclo item nr. T/E:





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Super_Sport

Subscribed.

Love these mystery frames.

Road Fan

I think the original pic of the downtube, showing the added shift lever clamp, supports that. It looks like the bike was originally made for a single front chainring and a rear derailleur. But it also looks like an original downtube braze on was removed (drive side). Was there a similar witness mark on the non-drive side?

Designing the frame for single shifters and adding a single clamped on lever was common for French bikes even up to the late '60s or early '70s. I have a '70 ish UO-8 that was made like that.

Dieptriest

did you take a look at this site? www.classicrendezvous.com/France
it's more for the racing bikes, but maybe you see some similarities with yours.

that's how i found the brand and model of my daughters bike. a Jeunet Captivante model 190.

and when i look at the pictures, i see some similarities with LeJeune models.

1speed4me

Interesting bike, made any more progress with it?

I just now joined this site after this thread popped up on a google search for "French 650b". I'm currently building/acquiring parts for a bike that I would like to use old 36h 650b hoops on. Are these hoops in good condition, and if so would you sell them? Or maybe you have another pair that you would consider letting go?

Apologies for posting this here, being a new member doesn't allow me to PM just yet.