Look 381 frame hanger

Look 381 derailleur hanger: features and specificities

The Look 381 derailleur hanger is a small component that plays a crucial role in the durability and performance of a road bike. Often overlooked, it is an essential part of the frame structure, as it connects the rear derailleur to the rear triangle of the bike.

What is a derailleur hanger ?

A derailleur hanger is a metal or alloy piece attached to the bike frame near the rear dropout. It holds the derailleur in place and absorbs shocks in case of a crash or derailment. On a high-end frame like the Look 381, the hanger is designed to protect the carbon frame by acting as a mechanical fuse: the hanger bends or breaks, but the frame remains intact.

Features of the Look 381 derailleur hanger

• Specific compatibility: this hanger is designed exclusively for the Look 381, an iconic frame from the French brand.

• Durable material: usually made from CNC-machined aluminum, it combines stiffness and lightness, in harmony with the frame it complements.

• Precise fit: its machining respects the exact tolerances of the Look frame, ensuring perfect alignment of the rear derailleur and smooth gear shifting.

• Safety component: in case of impact, it can be replaced easily, preventing damage to the carbon frame or rear dropout.

Specificities of the Look 381 frame

The Look 381 is a legendary frame, ridden by professional cyclists in the early 2000s. Made from monocoque carbon, it stands out for:

• Its lateral stiffness, offering optimal power transfer.

• Its vertical compliance, thanks to the design of the seat stays.

• Its race-oriented geometry, inherited from the Look bikes used in the Tour de France.
  In this setup, the derailleur hanger plays a discreet but vital role, ensuring drivetrain reliability while protecting the carbon structure.

Why replace a Look 381 derailleur hanger ?

Over time, a hanger can bend, crack, or break, especially after a crash or lateral impact. A misaligned hanger quickly results in:

• Inaccurate gear shifting.

• Risk of chain drop.

• Extra strain on the derailleur and chain.

Replacing it with a hanger specifically designed for the Look 381 restores smooth and precise shifting performance.

In summary

The Look 381 derailleur hanger is much more than a small spare part: it’s a strategic component that protects the carbon frame and ensures the proper function of the rear derailleur. Easy to replace in case of damage, it helps maintain both the performance and longevity of a legendary frame like the Look 381.