The Shimano Ultegra RD-R8150 brings Dura-Ace-level electronic shifting precision to the Ultegra R8100 groupset — with 58% faster actuation than the previous-generation Dura-Ace RD-R9150 and a fully integrated wireless unit that eliminates the need for a separate junction box. Whether you're sprinting for the line or navigating a technical descent, this derailleur delivers fast, accurate, silent shifts every time.

Highlights

• 58% faster shifting than the previous-generation Dura-Ace RD-R9150
• HYPERGLIDE+ technology enables precise shifting under extreme pedalling load
• SHIMANO SHADOW RD mechanism — super low-profile design prevents chain-stay contact
• Integrated D-Fly wireless unit, charging port, LED indicator, and function button
• Single cage length handles all compatible cassette configurations (up to 34T)
• Wireless communication with STI levers; wired to BT-DN300 battery via EW-SD300 cable
• Four fluorine-coated link bushings for smooth, consistent movement
• Aluminium cage plates with GFRP body construction for stiffness and light weight

Di2 Integration & Wireless Connectivity

The RD-R8150 integrates the D-Fly wireless transmitter, LED status indicator, function button, and USB charging port (EW-EC300) directly into the derailleur body — no separate E-tube junction required. The rear and front derailleurs connect to the BT-DN300 battery via EW-SD300 wired cables, while shift levers communicate wirelessly via Bluetooth and ANT+. A replaceable charge-port cover protects the connector in all conditions.

HYPERGLIDE+ & Shadow RD Technology

HYPERGLIDE+ chain profiles work in concert with the Di2 actuator to deliver fast, precise shifts in both directions — even under high pedalling load. The SHIMANO SHADOW RD design keeps the cage tucked low to eliminate chain-stay strikes during rough or aggressive riding, contributing to quiet, smooth operation at all cadences.

Construction

The cage uses aluminium plates for lateral stiffness, paired with a glass-fibre reinforced polymer (GFRP) body and composite sealed-bearing pulleys (11T guide and tension). Four fluorine-coated link bushings reduce friction and extend service life. The result is a 262g derailleur that punches well above its weight class in real-world performance.

Compatibility & Fit

The RD-R8150 is designed for the Shimano Ultegra R8100 12-speed road groupset and is cross-compatible with Dura-Ace R9200 Di2 system components. It supports compact (50/34T) and semi-compact (52/36T) cranksets with a maximum front chainring difference of 16T and a total capacity of 39T. Compatible cassettes include CS-R8100 and CS-R9200 in 11-28T, 11-30T, and 11-34T configurations. Compatible STI levers: ST-R8150, ST-R8170, ST-R9250, ST-R9270, ST-R8060, ST-R9160, ST-R9180. Mount type: conventional (direct attachment).