VintageSteelEU

I have recently purchased a new (old) Motobecane frame. As you can see in some photos, it had Italian Columbus stickers, which were obviously fake (and the seller was upfront about that). According to the seller, the frame is Reynolds 531. He bought the bicycle 10 years ago, so I'm guessing that's what he has been told by the previous owner (and not much else). I have no idea if it's 3 R531 tubes or 9 and can't see any obvious markings. I also don't know what Motobecane model or year it is, so I'm hoping the wealth of knowledge of this forum members will be able to fit the gaps. Any help will be much appreciated

So, let's start with things I know.
1. Head badge seems to be original to the bike. Haven't removed it yet (I've built a bicycle on the frame the day I received it to be able to do work on my previous one and still have something to ride on), but it looks as legit as any I've seen so far. As far as I know, this type of head badge was used from 1978 onwards (no idea if they stopped using it at some point, judging by the catalogues they kept using this one until the bitter end in 1984).
2. Headset is a mash-up of Motobecane's cones with Stronglight V4 Competition locknut. So I'm guessing it was Motobecane one originally and the old locknut got damaged or was looking natty (Stronglight one is in a very good condition). In itself, it's not that important, but I think it would suggest it was a bicycle for the domestic market possibly?
The reason I'm thinking that is the lugs (Bocama Professional cut-out?), which suggest higher tier model (they used simpler lugs on mid range and lower end) and that would mean either Shimano or Campagnolo headset. Then again, the whole headset doesn't have to be original to the bike.
3. Lugs look like Bocama Professional with cut outs. I understand Motobecane used Nervex lugs in early - mid 70's and in late 70's they used non-cut out ones for lower end / mid range models and cut-out ones for higher end of their range. This would point to a Grand Jubilee, Grand Record, Le Champion or Team Champion range of the bicycle (or C range in continental Europe)
4. First thing that puzzles me. Ending of seat stays, sort of wrapped around the seat tube lug. Not completely, just a bit. I think this would rule out Team Champion (which is fine, these are great bicycles anyway)
5. Second thing that puzzles me is a seat stay bridge. It's sort of plain. Again, that would seem to rule out Team Champion.
6. Speaking of seat stays, there is no brazed on chain holder (???) and no sign it was damaged or removed.
7. Next puzzling thing. Mudguard eyelets on chain stays and font fork. Surely they wouldn't put them on Team Champion on Le Champion (racing models). Did they put them on Grand Record or do these mean I have Grand Jubilee or European equivalent?
8. Bottom bracket shell had originally two cable guides brazed onto it (one is missing).
9. It has several holes at the bottom, these look like they were there from new. Though the bottom bracket itself (aluminium protective shell) had indents (maybe 0.5mm deep and concave) in corresponding areas looking like someone did use a drill.
10. No braze on bosses for shifters (so needs clamp-on downtube shifters)
11. Paint is genuine (not sure if inside the lug cut-outs and on the BB shell as well)
12. Rear brake cable guides are braze-on.
13. Seat post appears to be 26.8mm
14. Dropouts are Huret

The date might be sorted. I had a closer look at the bottom bracket and there is J?9 stamped in there. This might not correspond with anything at all, but could it mean it was assembled in 1979?

cb400bill

Pic Assist - https://www.bikeforums.net/g/picture/23945303

satbuilder 

Motobecane Champion Team bicycles in the late 1970's (the blue ones) were made with Columbus tubing. As I understand it, there was a falling out with Reynolds over 753 tubing.

What is in the photos however, does not look to me like a Champion Team frame.

unworthy1

very interesting frame: I do think you have something from the European market but there are some similarities to the approx. 1979 US model Grand Record. For example the long-point BCM lugs, the Huret ends and the cable choices which have above BB for the drive cables but clamp-on shifters plus cable barrels for the rear brake cable.
Also the fork crown appears similar.
If yours is built from the same spec'd tubing it may be 3-mains Vitus 172 and fork blades, the remainder unknown steel.
Never seen a BB shell with what seems like the FD guide snapped off or...?
otherwise good chance the components were different as the USA model came with mostly Shimano 600EX.
the seatpost is a bit suspect I suggest you check the OD of the seat tube to determine if this frame has Metric or Imperial tubing and then re-check what seat post should fit a Vitus 172 tube (assuming this is what you got).
Take a look at this catalog scan from Velobase and see yourself what I have been referencing: Motobecane Catalog 1979

T-Mar

It has the Huret dropouts with the integral cable stop, so it's no older than 1978 model year. Detail photos are great but I'd like to see an overall phboto and one of the stay caps.

noobinsf 

According to the catalog unworthy1 posted above, it looks like the 79 Grand Record came in that blue, and it would have come with a black headset locknut, which may be why the previous owner decided to swap it for a chrome one.

VintageSteelEU

General view
I uploaded more images initially, but somehow they didn't get through. Big thanks to the moderator for salvaging the ones present.

Here are the seat stays:

VintageSteelEU

Personally I'm not fussy about the tubing too much. If it's 172, I'm happy, if it's Reynolds, that's ok too. One easy way to tell would be stripping the paint, but I'm not quite sure whether I want to repaint it in original colour or just touch up.
As for the BB cable guide on the non-drive side, perhaps it sustained damage somehow (not sure how that could happen though) or one of the previous owners didn't want it for some reason. Whatever happened, the base of it is still there, so the top must have been removed and filed smooth. Which is also why I think the grey paint on the BB is not original (also, there is blue one underneath visible through the scratches to the top grey / silver coat).
Seatpost diameter-wise, the seat tube is 28mm and the current seat post is 26.8mm. Fits alright, doesn't seem to be too loose. Perhaps it could be a bit wider, looking at the back of the seat tube. I have 27 and 27.2mm seatposts somewhere and I will try them next week.
As for the diameters in that catalog, I've been informed previously by Verktyg in another thread that some of those are incorrect.

due ruote 

Interesting. I have a 1978 Team Champion (Columbus SL) and the Venn overlaps are these:
Bocama lugs with cutouts.
Color (Brilliant Blue).
Huret dropouts (mine lack the eyelets).
Fork crown/reinforcements/chrome appears identical.
Top tube cable guides are identical.

Among the differences I see:
Stay caps are flat on this bike; mine are concave.
Stay ends at the dropout are rounded; mine are fish-mouth.
This bike has cable guides on the BB; mine uses a clamp-on guide (although the 78 catalog indicates they should be brazed on).

So I would say it's clearly not a TC, but whatever it is, it's quite nice. The fender eyelets are a bonus in my opinion.

repechage

That chain stay crimping was seen on other Reynolds 753... Motobecane had a falling out with Reynolds allegedly regarding 753...
If you were a bike mfg and had this tubing hanging around that you could not otherwise officially use...

I have a later 70's TC and I am not sure What it is made of. Steel tubing definitely.

VintageSteelEU

The colour is great. I'm going to do my best to keep it and focus on touching up as opposed to full repaint. I don't know what these guys at Motobecane were using to paint their bikes, but it's better than almost enything I've seen riding around town. I had to repaint my previous one (no chance for saving the paint, too much damage) and it looks good, but original Motobecane paint is in a league of its own.
I have a 1979 C5 (European equivalent of TC) frame, which came to me in a pretty bad shape and still requires sending off to a frame builder for some repairs. Huret dropouts the same style, minus eyelets, chromed fork crown (the whole fork is actually chromed underneath the paint, which I suspect is the case with the blue one as well). It has both derailleur cable guides on the BB shell and the same lugs. Differences, other than eyelets: different seat stay caps, different style seat stay bridge. And, as mentioned, no eyelets.
My previous Grand Sprint had no eyelets either (and no BB cable guides, which I actually prefer), I was using chromed and rubberised P clamps. Hence mudguard on the blue still looks wonky, I transplanted all the components from the previous frame (which will be built up with nearly all French / Swiss components except for the seat post) and didn't have the time to adjust the mudguards properly yet. P clamps are a decent enough solution, but I definitely prefer to just use the eyelets.

due ruote 

I agree about the color. I got mine new and kind of babied it, so it’s in fairly good shape. But for the occasional nick, the color match has been vexing. Metallic blue Testors is decently close, but I’ve not been able to tweak it to really match. A body shop scan might be required.

unworthy1

if your measurements are accurate, a 28mm seat tube (Metric tubing) with PROPERLY sized 26.8 seat post means a wall thickness of 0.4, which is very thin-walled. This is in the neighborhood of Reynolds 753 tubing, lighter stuff than 531DB or Vitus 172 DB, AFAIK. Typical seat post for Metric 531 DB should be 26.4 (or sometimes 26.6) and note there's no butting in the top of the seat tube.
So I am still in doubt of something being correct in this here scenario: either the OD of the seat tube, the size of the seat post, or that the post fits that tube.
But I will stand to be corrected...

VintageSteelEU

Seat tube diameter is approximately 28mm. Depends where you check and there is, of course, some marigin of error, even with digital calipers Didn't get close to 28.6 anywhere on that tube, so I'm going with 28mm.
According to the catalogues and corrective information on this forum, the top tier of Motobecane bicycles from around 78 / 79 should have 26.6mm seatpost. But, I did ask about Motobecane seatposts before and got some answers here: Motobecane C5 / C51 1979 / 1980 seatpost diameter
Very good info from Verktyg there.

The seatpost currently in this blue Motobecane is a modern, but cheap and cheerful seat post I got based on the measurements by the previous owner. I have ordered a nicer Stronglight aero, but wasn't sure if it's going to arrive on time and ended with two 26.8mm seat posts. I have some seat posts in various diameters, so I will be able to test this seat tube. But, the current seat post seems to fit pretty well. Whether this would be measurement stated by Motobecane when the bicycle was being sold in a shop, I don't know. If anything, it would seem that it might actually be undersized. I'm not basing this on any scientific or measured qualities, I'm basing it on the tactile feedback when installing it. I will run some more thorough tests and measurements next week, for now I needed the bicycle on the road, so the only thing I did was to gently go with a rounded file around the inside of the seat tube, but that didn't do anything to the actual wall thickness.
The thing is, how well these seat posts I have have been measured before the stamping. What was happening to the seat tube during production of the bicycle? Did they choose the right seat tube or grabbed one from another source, because of some mix-up? How the bicycle was used throughout the past 43 years, was it ever knocked down, was the seat tube ever hit with something heavy? These are all questions I wouldn't be able to answer, so my attitude right now is:
1. Take a setpost that's close enough and see if it fits.
2. To loose? Grab one with a larger diameter.
3. Too tight? Grab one with a smaller diameter or if it's just a bit too tight, a piece of sanding paper.

unworthy1

Chas certainly knows his stuff especially when pertains to Gitanes and other FR makes. I would follow his very well-presented advice and also do your own "GO, NO-GO" test fitting as you intend, and watch the gap at the back of the seatlug for no pinching.
I am really happy with my own US model 1974-ish Grand Record (full 531DB and the black/red-orange paint scheme) it really delivers on the "French Ride promise"!

SurferRosa

Be nice to see the underside of the BB shell.

VintageSteelEU

Here we go. Please note that what in photo 3 looks like bad rust is, in fact, just bad lighting.

VintageSteelEU

I will try to get it to some local body shop and see whether they are able to match the colour. Should I get something Like a RAL value, I'll be sure to report it here. Would be nice if we could have some sort of database of Motobecane paint colours from various periods and modern equivalents...

And an update on the frame identification. When it comes to seat posts, I have tried 27.2mm, 27mm and another 26.8mm. 27.2 is no go. 27mm will go in and can be taken out, though the fit is a bit tight. Not overly so, it doesn't have to be forced. Another 26.8mm is more or less as the current one - will go in fairly easily but not drop in or silde in under its own weight and can be taken out fairly easily. So probably the correct diameter would be somewhere between 26.8mm and 27mm.

Looking at the photos of the steerer tube I have noticed an additional stamp I didn't see before. There is "NERVOR" stamped above the for race, very faintly. Took additional photo (below). I'm aware of Nervar and Nervex, but never heard of Nervor. I've seen some other posts mentioning it (in all the photos I've seen so far it's amuch bigger stamp and more pronounced than on mine), but nothing conclusive so far. I guess need some more research into this.

VintageSteelEU

Well, still can't be 100% sure and I would have to strip the paint to figure out what tubing it uses, There would be clear stamps underneath it. It is lighter than my GS with Vitus 888 tubing, with the same components (and exactly the same size). So it would have to be V172, R531 (as the seller claimed) or C SL (which it's not).
But I had a look at every 78/79 Motobecane photo and catalogue I could find (not a bad task), comparing various models, lugs, forks, seat stays, BB shells etc. Definitely Bocama lugs and they are cut out, which would leave us with Grand Jubile, Grand Record, Le Champion, Team Champion - or the continental Europe equivalent (CT/CTM 3, C3, C4,C5). GJ and GR had short ones, so LC and TC. Then looking at the seat stay caps, definitely not TC / C5. There are some models in 1978 which seem to have similar seat stay caps (C2 and C3 - Grand Sprint / Grand Record, at least as much as I can see in the catalogue, that's not always consistent with photos of C2 and C3 I found elsewhere), but they also have short Bocama lugs. This combination leads me to believe that this blue frame might be C41 (or Le Champion equivalent) from 1979.
Comparing the way it rides to my previous Grand Sprint frame, I have to say there doesn't seem to be much of a difference. GS seemed to be a bit happier taking narrower turns, but then I was riding it everyday for a year, whilst I'm still getting used to the current one. It is different, but can't put my finger on how exactly quite yet.