Motobecanes are a point of contention in most bike shops. The brand was once one of the top three French bicycle manufacturers, the other two being Gitane and Peugeot. In their heyday all of these companies manufactured bikes that were worthy of the Tour de France. Unfortunately, here in the United States, we mostly see the dregs of their production line, the thousands of budget-oriented Bike Boom ten-speeds that these companies shipped overseas in order to make a quick buck. It's these Bike Boom-era relics that have created the groundswell of distaste for French bicycles in the bike shop world. Like most machines from the Bike Boom, these bicycles tend to be cheap, heavy, poorly functioning, and with really awful parts. They're hard to service and, particularly in the case of French bicycle manufacturers with their penchant for non-standard part sizing, they are becoming increasingly difficult to find replacement parts for.
This particular Motobecane stands in stark contrast to most Motobecanes that I have seen, and is a beautiful reminder of what the company was capable of. Made of high-quality steel, with some very elegant brazing and neat design touches, it's simply a great old bike. It helps that it shipped with Campagnolo components and that the owner has kept it in great shape. Based on the components on the frame this particular bike dates to the early 1980s, probably '81-'83. There are no particularly rare items to be found on it, but everything on the bike is nice, clean, works very well, and adds up to a vintage bike that's worth keeping. However, I would be heartbroken if some clueless hipster out there decided to turn this thing into a fixie. It's not going to win the Tour any more, and it might not be great for doing serious road riding, but its much cooler as a fully-geared functional road bike than as a bastardized fixie conversion with pursuit bars and purple Deep-V's.
The Maillard Helicomatic
There is one component on the bike that is worth mentioning, if only because it can cause problems down the road. Maillard, a French bicycle component manufacturer, developed the Helicomatic freehub system in the early '80s. It shipped on a large number of manufacturer's bikes, including Motobecane and early Trek road bikes, and was quite common at one point in time. The Helicomatic freehub was designed to step around some of the problems associated with multi-gear freewheels, specifically how hard it could be to get a freewheel unstuck from a hub (it usually involves large tools, a bench vice, and a special freewheel removal socket), and the fact that freewheels, especially once they began using six and seven gears, had a tendency to bend axles due to the unbalanced torque load that was placed upon the rear wheel.
The Maillard Helicomatic is elegant in its own way, and prefigures Shimano's freehub cassette body that would eventually come to dominate the bike market. The freewheel mechanism slides onto a rigid hub body that is covered with helical splines and is held in place with a lock ring. The lock ring was easy to remove with a special Maillard tool (or pipe wrench if the tool is not available, just be gentle), and the splines meant that the gears were easy to remove from the wheel. Placing the bearings farther outboard meant that the problem of bent axles could be avoided. The freewheel itself could also be disassembled so that custom gearing options could be created. The Maillard Helicomatic tool is worth mentioning because it's pretty neat in its own right. It had a splined lockring removal tool, a bottle opener, and a spoke wrench all in one handy package. They're hard to find these days since most of them have been relegated to bottle-opening duty by the bike mechanics of the world.
But this doesn't mean that you should go right out and replace all of your Helicomatic rear wheels with modern parts. These wheels worked fine-ish when they were in good shape. More than likely anyone should be able to use these parts until they explode and replace them when necessary. Just keep in mind that small issues could lead to replacing the back end of your bike.