Freewheel Atom 4 speed

Atom 4-speed freewheel: an iconic component of vintage bicycle drivetrains

In the world of vintage bicycles, some mechanical parts have stood the test of time and earned a legendary status. Among them is the Atom freewheel, a key component of the drivetrain on many bikes from the 1960s to the 1980s. Especially sought after in its 4-speed version, it still appeals today to restoration enthusiasts, vintage touring cyclists, and collectors of classic bikes.

What is an Atom freewheel ?

A freewheel is an essential part of a bicycle’s rear transmission system. It threads onto the rear hub and allows the wheel to rotate when pedaling while permitting coasting when the rider stops pedaling. “Atom” refers to a well-known French manufacturer, active during the mid-20th century, famous for producing durable, affordable, and precise freewheels.

The Atom 4-speed freewheel is recognizable by its French-threaded hub compatibility (34.7 x 1 mm), making it a match for many hubs of that era, including those from Maillard or Normandy. It was commonly fitted to road bikes, city bikes, and touring bicycles produced during the post-war golden age of cycling.

Technical specifications of the Atom 4-speed freewheel

Here are the typical features of this classic component:

• Number of cogs: 4-speed (often 14-17-20-24 teeth or similar)

• French thread: 34.7 x 1 mm (not to be confused with English/BSA threading)

• Steel body: solid construction, sometimes with reinforced rings

• Ratchet mechanism: reliable internal pawl system, simple to service

• Compatibility: works with vintage friction derailleurs (Simplex, Huret, Sachs, etc.)

• Approximate weight: 400–450 grams

Thanks to its robust design, the Atom freewheel remains a trusted choice for mechanics and restorers working on classic bike drivetrains.

Why choose an Atom freewheel for your vintage bike ?

Using an Atom freewheel helps you stay true to the original period of your bicycle. It ensures historical authenticity while still offering decent performance for light riding or display purposes.

Main benefits include:

• Easy maintenance: ball bearings can be cleaned and re-greased with basic tools

• Original vintage part: ideal for accurate restorations

• Broad compatibility: fits many classic steel frames and hubs

• Easy to replace: standard French thread, compatible with most vintage freewheel tools

Final thoughts

The Atom 4-speed freewheel is more than just a mechanical part – it’s a symbol of a cycling era where function met elegance. Sturdy, simple, and satisfying to ride, it remains a top pick for lovers of vintage bicycle drivetrains. Whether you're restoring a Peugeot, Motobécane, or Gitane, this iconic freewheel will bring your old-school ride back to life.

Looking for vintage drivetrain parts? Browse our shop for classic freewheels, derailleurs, and cogs to complete your retro rebuild !