Shimano Rear Derailleur CUES RD-U4020 – 2×9-Speed, Long Cage, Black

Shimano CUES RD-U4020: Smooth Shifting for Everyday Riding

The Shimano CUES RD-U4020 rear derailleur is designed for smooth, well-defined gear changes and dependable everyday performance. Specified for a 2×9-speed drivetrain with an 11–36T cassette, this black long-cage model combines SHADOW design with Top Normal operation.

From a ride through the city to a route out into nature, the RD-U4020 helps make regular cycling a comfortable part of your routine. It is engineered and tested for sustained performance with e-bikes, provided the complete drivetrain is compatible.

Key Features

• 2×9-speed specification: For a compatible drivetrain with two front chainrings and nine rear sprockets.
• Smooth, defined shifting: Designed for comfortable, predictable gear changes.
• Everyday reliability: Developed for regular riding.
• E-bike suitability: Engineered and tested for lasting performance with e-bikes.
• SHADOW design: As specified for this model.
• Long cage and Top Normal: The configuration supplied for this listing.

Specifications

• Brand: Shimano
• Series: CUES
• Model: RD-U4020
• Drivetrain: 2×9-speed
• Specified cassette range: 11–36T
• Design: SHADOW
• Cage: Long, SGS
• Operation: Top Normal
• Colour: Black
• E-bike suitability: Yes, with a compatible setup
• Manufacturer article number: ERDU4020SGS
• Article number: 2091123820
• EAN: 4550170172039
• Supplier code: 4055149509934

Compatibility and Installation

This listing is specified for a 2×9-speed, 11–36T setup. Do not assume compatibility with an 11–46T cassette. Confirm Shimano's compatibility information for the shifter, chain, cassette, front gearing and mounting arrangement before installation. Follow the manufacturer's fitting and adjustment instructions.

Frequently Asked Questions

Which drivetrain is this derailleur specified for?

The supplied specification identifies a 2×9-speed drivetrain: two front chainrings and nine rear sprockets.

What cassette range is specified?

The stated range is 11–36T. Do not treat this as an 11–46T model.

Is it suitable for e-bikes?

Yes. The supplied product details state that it is engineered and tested for sustained performance with e-bikes. Confirm compatibility with the complete drivetrain.

Does it have a long cage?

Yes. This version has a long cage, identified by SGS in the manufacturer article number.

Does SHADOW mean it has a clutch?

The supplied information specifies SHADOW, not SHADOW PLUS, and does not confirm a clutch. A clutch function is not claimed in this listing.

Will it work with any 9-speed shifter?

Do not assume universal compatibility from the speed count alone. Check Shimano's compatibility information for this exact derailleur and your shifter.

What colour is this version?

This listing is for the black RD-U4020.