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Shimano Ultegra RX RD-RX800 11s Rear Derailleur Shimano Ultegra RX RD-RX800 11s Rear Derailleur
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Shimano Ultegra RX RD-RX800 11s Rear Derailleur

Mfg PartNum:IRDRX800GS
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Backorder: This item is currently not in stock but is available to purchase today as a backorder. The expected availability date shown above is our best estimate as to when it will be shipped to you, but this date is subject to change based on our receipt of this item from its vendor. Shipping in the continental US is free for all backorder items (for international orders, our customer service team will contact you when the item is available to ship). Your credit card will not be charged until your item ships (Paypal requires payment up front, but you can cancel for full refund). Anytime prior to shipment, your backorder can be cancelled by contacting our customer service team.

Shimano's Ultegra RX RD-RX800 11s Rear Derailleur features a clutch design that eliminates chain drop on rough terrain and provides a better interface with a Shimano 1x set up.

B-Stock - This product has one or more B-Stock units available. These units can be purchased at a discount (see option select). B-Stock units were returned from other customers and may have missing or damaged packaging materials. These units are otherwise as new. The full manufacturer warranty applies. Click Here for more information.

Mfg PartNum: IRDRX800GS 

Ordered by Most Relevant First
5 stars
4 stars
3 stars
2 stars
1 stars
Reviewed 11/5/2018
by ScottieMo
Daily Commuter
New England
Value Rating
Overall Rating
5 of 5 customers found this review helpful.
One of my favorite upgrades

Conclusion A clutched rear mech will probably become a standard for everyone but triathletes.

I bought this upgrade to replace a dying 6800 rear mech. I am a daily commuter, mixed surfacelong ride weekender. Shifting is crisp, but the real pleasure has been a lack of chain slack or slap. My chainline stays tight no matter where I'm riding. I ride over potholes, train tracks, dirt trails, fire roads and overall poorly maintained roads. The other nice part is that the cable is now tucked underneath everything rather than to the outside in the 6800 series, so it should take less abuse. Adjustments on the barrel adjuster are easier as well.

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Reviewed 1/21/2021
by Anonymous
Competitive Racer
Value Rating
Overall Rating
3 of 3 customers found this review helpful.
Fantastic for taking your bike offroad!

This is such an amazing difference for a cyclocross/gravel bike. When I ride on the road I mostly leave the clutch flipped off (it makes the shifting a little stiffer), but when I get to a trail it's easy to flip on and almost entirely eliminates the chatter of your chain on the chainstay. I find that it helps keep the chain from jumping gears or falling off in very rough stuff as well. I don't notice the stiffer shifting action amid the bumps of riding offroad, so that's a non-issue for me. Mostly, it's soooo much quieter to ride down a trail. I love it!

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Reviewed 8/5/2019
by Otto Von K
Overall Rating
1 of 2 customers found this review helpful.
Very smooth

Works as advertised. Im primarily a road cyclist but love that I can tighten up the chain for excursions on gravel and modest dirt tracks.

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Reviewed 7/1/2019
by Anonymous
Overall Rating
Great upgrade

Needed a replacement for my worn 105 derailleur and wanted a clutch. This fit the bill, shifts are crisp, no complaints.

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Reviewed 11/2/2018
by Dolan
Competitive Racer
Overall Rating
5 of 5 customers found this review helpful.
So far, so great

So, it adds 40 grams over a standard Ultegra derailleur, but if you're looking at this, you know it's well worth it. After a number of CX races and gravel rides with it, the clutch noticeably works in the sense that you don't notice the chain slap you did before, and you don't notice your chain dropping. There's a little bit more friction, and shift effort is a tiny bit higher, but well worth it for the peace of mind this derailleur gives you.

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