Look derailleur hanger

Look derailleur hanger: a key component to protect your bike frame

When we think about transmission and performance on a road bike or MTB, we usually focus on derailleurs, the chain, or the chainrings. Yet, one small part plays a crucial role in protecting your frame and keeping your drivetrain efficient: the Look derailleur hanger. Specifically designed for Look frames, it ensures a solid connection for the rear derailleur while acting as a safety device in case of impact.

What is a Look derailleur hanger ?

The derailleur hanger is an aluminum piece, sometimes forged or CNC-machined, that connects the rear derailleur to the bike frame. On a Look frame, it is shaped to perfectly fit the stays and dropout area, respecting the geometry and alignment of the rear triangle. Its two main functions are:

• Providing a solid mounting point for the rear derailleur, ensuring smooth and accurate gear shifts.

• Protecting the frame during a crash or impact: the hanger bends or breaks before the carbon or aluminum frame is damaged.

Features of a Look derailleur hanger

Each Look frame model requires a specific derailleur hanger, which explains the wide variety of references available. Key features include:

• Compatibility: every hanger is designed for a particular Look frame series (road, gravel, or MTB).

• Material: most are made from lightweight yet durable aluminum.

• Fixing system: usually attached with two bolts to the rear dropout for maximum stiffness.

• Precise alignment: essential to maintain smooth shifting and prevent premature drivetrain wear.

Why replace a Look derailleur hanger ?

A Look derailleur hanger can easily bend after a crash, a side impact, or simply through long-term use. Common symptoms include:

• misaligned rear derailleur;

• inaccurate gear shifting;

• chain skipping;

• unusual rubbing noises.

If you notice these issues, it’s best to replace the hanger immediately to protect both your transmission and your frame.

How to choose the right Look derailleur hanger

To find the correct hanger for your Look bike, you should check:

• the exact Look frame model (frame number or production year);

• the type of rear derailleur mounting system;

• the compatibility with your drivetrain (Shimano, SRAM, or Campagnolo).

Today, many manufacturers offer original or compatible Look derailleur hangers, making replacement easier while maintaining your bike’s performance.

In short, the Look derailleur hanger may be a small part, but it’s essential for protecting your frame and ensuring optimal shifting performance. A small investment that can save you costly repairs and keep your rides smooth and safe.