Vintage SIMPLEX Rear Derailleur for Old Mercier Gitane Bikes DAR14

DAR14: the right rear mech for a French classic

The Simplex DAR14 answers a recurring problem on 1970s French machines: finding a rear derailleur that actually belongs on the frame. If you are assembling a Mercier or Gitane and the existing mech is mismatched, worn beyond use, or simply missing, this is the component that restores the drivetrain to a coherent, period-plausible state. The body combines plastic and steel, exactly as the original units did. No oxidation is noted on this example.

This is not a modern replacement hacked onto a vintage dropout. It is the rear derailleur that many French touring and sport builds were designed around. The photos are part of the description: they show the actual condition, wear pattern and the plate finish, so inspect them closely before committing to this piece for your project. Minor cosmetic marks from storage may be present, as expected on any fifty-year-old component that has not been refinished.

Why it matters for a period build

Vintage rear mechs are not interchangeable in the way modern gruppos are. The DAR14 sits in a narrow window: it works with the cable routing, dropout geometry and chainline that were standard on many French road frames. If you already have a Simplex front mech or shifters on the bike, this rear unit completes the set. It is worth checking the pulley cage and spring action on arrival; on this sample no major mechanical defect is flagged.

The steel/plastic build keeps the weight reasonable while remaining robust enough for distance riding. That mix was a hallmark of Simplex production in this era and is not easy to find in good condition today. Many surviving examples show heavy oxidation, but this one is listed with no rust.

Key specifications

• Oxidation: No
• Country of origin: France
• Material: Steel/Plastic
• Manufacturer part number: 0000

For a complete Simplex drivetrain, consider pairing this DAR14 with a matching Simplex rear derailleur for Peugeot, Gitane and Mercier builds or a Simplex SLJ rear derailleur for Peugeot PX10 and Eroica machines if you need a slightly different cage length or ratio. Both share the same French production lineage and visual language.