Model: Motobécane BG 42
History: The commercial success of the Solex made many envious.
Motobécane, despite the sales of its mopeds, was one of them.
Launched in the 1950s, the Motobécane BG was intended to be a direct competitor to the Solex. With its roller drive and engine under the bottom bracket, the BG was also considered "safer" in terms of handling.
However, this machine did not achieve the commercial success Motobécane had hoped for. The simple Mobylette was more powerful than the roller-driven model.
Nevertheless, this moped, like the BG 43 that succeeded it, is a torquey, easy-to-use machine and perfectly at home in a collection of roller-driven mopeds.Work to be done: This moped was aesthetically in quite good condition, but the engine was out of order. Therefore, it was necessary to:
Restore the frame while preserving the original patina,
Completely overhaul the engine, improving performance,
And naturally replace all worn parts for maximum safety (tires, brake overhaul, etc.).
Timeline:
Complete disassembly of the engine and new overhaul: bearings, oil seals, carburetor: this engine remained "100% original". The completely "worn out" cylinder head was replaced with a newer Airsal model. Problem: this cylinder is square, whereas the original cylinder is round. It was therefore necessary to round the cylinder so that it could visually take its place in the assembly.
Complete disassembly and repair of the clutch: friction material, pads, etc..... and all this while respecting the fact that this clutch is entirely mounted in reverse of more classic ones since the engine itself rotates... in reverse.
Cleaning and polishing of the frame, repair of the "silver" stripes, as they were erased by wear and polish,
Polishing of chrome and aluminum,
Replacement of tires,
Reassembly and adjustment of the chassis, particularly the condition of the cabling and brakes, essential for rider safety,
Running-in of the entire assembly.
When riding, it's primarily a moped, therefore a more powerful machine than an original Solex 3800. Its ride is pleasant, torquey on ascents, and easy to use with its clutch.
It is naturally less adept at climbing than a chain-driven moped, and the roller tends to slip when the road is wet... nothing abnormal for a roller-driven moped. The slideshow shows the final result, and the video shows the proper functioning of the assembly.