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ShimanoUltegra Di2 RD-RX805 Rear Derailleur


Item # SHI00KT

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  • Gray, Long ($284.99)
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Item # SHI00KT

Ultegra RD-RX805 Rear Derailleur

  • New clutch-equipped Ultegra Di2 rear derailleur designed for rough roads and gravel
  • Clutch system improves shifting and silences chain slap when things get choppy
  • Compatibility with both 1x and 2x drivetrains as well as most Shimano Di2 shifters
  • Durable alloy construction will give you years of on- or off-road use
  • Long cage handles up to a 34t sprocket
  • Di2 electronic shifting is precise and can be customized
  • Low-profile Shadow design helps avoid damage from impacts or during a crash

Tech Specs
Cage Lengthlong
Capacity[long] 39t
Cassette Range[long] 11-28t through 11-34t
CompatibilityShimano Ultegra R8050 and 6870 Di2, Shimano Dura-Ace R9150 and 9070 Di2
Recommended Useroad
Manufacturer Warranty2 years

Actual Weight

Gray, Long

Claimed Weight

Claimed weights are provided by the vendor.

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Actual weights are measured in-house by the Competitive Cyclist team.

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What do you think about this product?


>Rating: 5

Extra gear range & added security

I've put it through the wringer

Made some upgrades to my gravel/CX bike this spring, including the addition of this RX derailleur. Coming from the 1x world, I knew how much I wanted to avoid chainslap when riding on rough surfaces but I wanted additional gear range while being able to run 2x set-up with 50/34 chainrings. This derailleur easily clears an 11-34 cassette and I'm sure folks have found ways to expand that even further. The on/off clutch system is pretty nice, really helps keep the chain under control. The only time I ever turn the clutch off is just to take my wheel off. If I do another Di2 build, I'm definitely getting this derailleur again.