Shimano R8000 derailleur hanger - Y3E998020

Shimano ’s Y3E998020 derailleur hanger is an essential mounting component for Shimano Ultegra R8000 11-speed rear derailleurs (and GRX/RX800-compatible models, depending on the setup). It connects the derailleur to the frame dropout, whilst also providing safety in the event of an impact.

It is sometimes referred to as a bracket axle unit or derailleur mount, and is a standard component of the Shimano Direct Mount / conventional mounting system.

What is this component used for?

This unit has several important functions:

• To securely attach the derailleur to the frame via the hanger
• To ensure the rear derailleur is correctly aligned
• To act as a ‘sacrificial’ part in the event of a fall (it bends before the hanger or frame breaks)
• To ensure compatibility between different types of frames and derailleurs Shimano R8000

It is therefore one of the critical yet cost-effective components of the drivetrain.

Compatibility

Part number Y3E998020 is used on:

• Shimano Ultegra RD-R8000 (11-speed)
• Certain GRX RX810 / RX812 versions
• Certain Ultegra RX (RX800) derailleurs, depending on configuration

It is available in several variants depending on the mounting type (standard / direct mount), but this version corresponds to the most common standard mounting.

Key features

• Genuine part Shimano
• Compatible with road and gravel bikes (R8000 / RX800)
• Quick and easy to fit
• Protects the frame dropout in the event of a fall
• Precise derailleur adjustment
• Low cost for an important safety component

FAQ

What exactly is this part for?

It acts as a link between the frame and the rear derailleur, whilst ensuring the system is correctly positioned.

Is this part essential?

Yes. Without it, the derailleur cannot be fitted correctly to a standard frame.

Can it be replaced easily?

Yes, it is designed to be replaced quickly in the event of impact or breakage.

Is it compatible with other groupsets Shimano?

It is primarily designed for the R8000 groupset, but may be compatible with certain GRX and RX800 derailleurs, depending on the setup.