zola1

Hi,

Can anyone help :-

Newbie here from the UK with some questions, i am in the process of carrying out a refurbishment of a Motobecane bike (model unknown !).

Here are some pictures enclosed could anyone advise me on what model/year/spec it is ?...as i would like to restore some of the original features ( crank is a modern Shimano with odd pedals etc) i do not know what the original Crank would have been ? any thoughts ?



this is not my bike but the headbadge is exactly like this one


The non original white paint is in very poor condition and i am in the process of stripping it back to metal to inspect and repair the frame, there were 3 layers of paint on top the original colour which is a light blue metallic finish that i found underneath the Headbadge,(which has paint bleed damage from a red paint job !...are the Headbadges available ?)..

I would like to fit the original style of decals to the frame and forks again any thoughts on suppliers ?

Her is a list of the specification of some of the parts fitted :-

Forks have "Huret" stamped on the lower wheel spindle bracket, Brakes are Weinmann, Derailller is Huret,Chrome clips holding the rear Brake cable to the top frame are "Sachs", Handle bar top yoke is "Pivo", Handle bars are "Pivo".



Any help would be much appreciated.

kind regards

Derrick

stevegreer

Derrick, it is a bit hard to tell since it's not the original paint job and it doesn't have all of the original parts. But if that is the original head badge, then it could possibly be a 1972 or 1973 Grand Touring or Grand Record. The only thing that makes me unsure is the design on the seat tube. Do you know what the frame material is? 1020 or Reynolds 531?
You can see the head badges here: VeloBase.com - Head Badge Gallery

zola1

Hi Steve,

Many thanks for the info, how do i differentiate between the frame materials you mentioned ?... "Do you know what the frame material is? 1020 or Reynolds 531"

here is a link i found https://www.retrobike.co.uk/forum/viewtopic.php?t=195804 thats a great looking bike ..thats what im looking at trying to get the bike look like.

Derrick

zola1

Here are some photos of the frame and forks :- there are some id no's stamped on the top of the forks, do they mean any thing ?



[ATTACH=CONFIG]443241



Derrick

stevegreer

I'm not sure about all vintage bikes, but my '87 Trek has a label on the seat tube close to the bottom bracket that tells the type of steel. I believe it is a foil sticker, so since your frame has been repainted several times, it is likely it was removed if there was one. As far as the type of steel, if it is a Grand Touring then it is 1020. If it is a Grand Record it is Reynolds 531.

The stamped numbers could either be a serial number from the manufacturer, or it could have been stamped by one of the owners to be used as an anti-theft ID. My dad took me and my brother to the local police station when I was a kid and they stamped and recorded a serial number on the underside of the bottom bracket on our BMX bikes. That way, if they were ever stolen they could be ID'd using those serial numbers. Not sure which is the case here. Maybe someone with more knowledge in that realm will be able to answer.

Here is a good link for the Motobecane catalogs (Many thanks to BigChief for posting this in another thread!). So many beautiful bikes in their lineups in the '70s and '80s! bulgier.net - /pics/bike/Catalogs/Motobecane/

wrk101

Method #1 : seat post OD.

Method #2 : Weigh the frame and fork accurately. Higher end should be around 5 pounds, maybe 5 1/2 pounds to 6 pounds MAX. Low end should be MUCH heavier.

Stamped number on steering tube could be date code. My guess "A76" = January 1976. "610" = maybe sequence number, no idea.

zola1

Thanks guys excellent advice, I will measure the seat post OD and the weights of the frame and forks. Looking at the specs it looks like the closet mine compares component wise is the Nomade or Mirage..I'll do the weighing that should help narrow things down.

Derrick

stevegreer

You could be right about the serial number. But if the A76 denotes the date of manufacture then that would lead me to believe that either the fork is not original or the head badge isn't. So the mystery deepens.

auchencrow

Measure the seat post. Generally a 26.4 or larger seat post diameter indicates a Reynolds '531 Moto frame.

zola1

On the base of each of the front fork drop outs it is stamped. " Huret" would this be the Derailer company ?

stevegreer

Yes. The '73 Grand Touring came with Huret derailleurs.

zola1

Here is a picture of the lower forks and the BB axle, the axle I am unsure of the make ? It has no's stamped on it but no make! It's dimensions are 122mm (not incl the threads) ..the crank is a modern Shimano set ... The bearing surfaces are pitted as are the chrome bearing cups so I would like to change the for these Bottom Brackets - Components but would like to keep the Chrome outer retainers. Has anyone done this mod ? Any tips

Derrick

stevegreer

That's a bit out of my realm. All I do know is that Motobecane BBs are French threaded. As long as you stick with French thread you should be fine.

zola1

Ok thanks .. Those French engineers chose some unique thread combinations eh, Its good to see that the Velo site stocks them at a good price. I will email them about how the BB assembly looks like when it is fully assembled with their part as I am unsure if their sealed bearing pack accepts the Original chrome locking plate !

wrk101

It won't, those are bottom bracket cups that go with a spindle. You either have to find a replacement spindle, or buy a replacement cartridge bb. Your choice.

rgver

Motobecane also used Swiss threaded BB.

stevegreer

That's good to know. Do you know what years and/or models?

rgver

I don't know when any change overs were, or what models they were used on. It was just something else to consider.

stevegreer

Ok thanks for bringing that up, though!

zola1

Thanks for the heads up on the spindle set up, I will make a call on that ref he info from you guys. Here are some frame shots , more Huret stamping on the rear drop outs ( does this just signify what was recommend as a Derailer or ?

Various numbers have been stamped on the frame not sure if they mean anything ? And the word Bom below the fork head ? Its interesting what they are for ?

Any thoughts guys ?

Any ideas what this grub screw is for ? Block of plastic looks u/s



Derrick

rgver

Huret is who made the dropouts, they are forged with an integral derailler hanger, certainly not what you would find on a low end bike.

eschlwc

a swiss threaded bb uses french threading, but the fixed cup follows the reverse threading direction (tightening to the left) like the british/iso standard. both my motos are like this ('76 and '80).

based on the headbadge, i'd say the bike is older than '76.

my '76 531 moto has a 26.6 seatpost.

kroozer 

The Motobecane line-up sold in the US was quite different from the European models. Different model names, finishes, components, etc.

stevegreer

You think so? This link shows a '72 and '73 that has the exact same head badge as his. I know that's not a true indicator since head badges can be changed, but it was the basis for my guess for his being one of those years. Do you have pictures posted of yours somewhere? I'd love to take a look at them. Motos are some beautiful bikes!
VeloBase.com - Head Badge Gallery

zola1

my hole size is 26.6mm for the seatpost mount.