Which Motobecane Is This?
 

A friend has got the Motobecane in the picture, but I don't find its serial number. Can you help with identifying the model?
https://cimg8.ibsrv.net/gimg/bikefor...3722ab6832.jpg
https://cimg2.ibsrv.net/gimg/bikefor...ad0d2eb6e9.jpg
https://cimg4.ibsrv.net/gimg/bikefor...4f3d4e065c.jpg
https://cimg6.ibsrv.net/gimg/bikefor...c7bc25178c.jpg

Look through specs here for components and colors that match

​​​​​​https://bulgier.net/pics/bike/Catalogs/Motobecane/

My guess would be late 70s to early 80s "Mirage."

If you ask here:

https://www.bikeforums.net/classic-vintage/

User T-Mar will eventually come along and tell you not only the exact date it was made, but the maker's name, and the names of said maker's wife and pets.

'83 Mirage.

Specs don't fit with the ones link Dirt Farmer's link, in particular mine is 10 speed, but that link says 83 mirage is 12 speed.

Thanks, just tried, let's see!

Thanks; This looks a great source.
I tried; strangely I didn't find any fit! Mine is 2*10 speed, 2040 tubing, hi resilient tubing, Huret groupset, colour is gold(ish). Any idea?

Many times bike parts manufacturers stamp a production date into the components. The one I use most often is the date code stamped into the inside of the crank arm. You can also look for a date stamped into the reverse side of the brake arms and in the center of the hub. That will give you a production date within a couple months of the bike being made.
This must be one of the cheaper models as Motobecane used Stronglight cranks on the better models. I owned a Motobecane Le Champion 10 speed for many years before giving it away when I moved on to recumbent bikes. Bikes made in France generally used French threaded components. The Japanese adopted the English thread used by most other brands so French threaded components are hard to come by.