Several members of the team rode the new Shadow RX derailleur at the 2017 Almanzo 100, but rain and temperatures that hovered around 40 degrees forced many of the team to skip the race or withdraw early. All told, only about 100 starters finished the event. Not exactly the best test conditions.

Price Matches may only be honored on identical items. The product must be the same make and model (i.e., the same size, color, year, etc.). series braking was considered benchmark and I think Ultegra R8000 exceeds it in terms of power and modulation. Shifting is also on par, and while R8000 weighs a touch more, you can easily lose that weight elsewhere on the bike. Since I started testing the new groupset, many have also asked me whether it is as good as Dura-Ace 9000 and I’d have to say, yes, pretty much. The added weight for the clutch is about 30-40g. The RD-RX805 model has a claimed weight of 280g (compared to 249g for the RD-R8050) and the RD-RX8050 weighs 248g (compared to 210g for the RD-R8000).

Shadow Geometry shifts the majority of the derailleur mechanism below the cassette and chainstay, keeping it out of harm’s way, leaving only the main pivot proud of the frame.

Accurate, dialled and metered shifting from a mechanical rear derailleur, the Shimano Ultegra R8000 11-Speed Rear Derailleur, GS provides neat, crisp and clear-cut shifting prowess to the rider looking for pinpoint accuracy in their rear derailleur. Both models come with a GS long cage that fits cassettes between 11-28t and 11-34t. Lawrence explained the company added room for the 34t cog after test rides on the steep gravel roads in Colorado. That’s pretty low for road 2x gearing, but a few steps away from the 11-42t many 1x users are used to (in case you’re thinking about a RX805 single chain ring setup).The new brakes also include the same ‘booster’ bar that was introduced with the new 9100-series brakes. This thin metal plate sits between each of the brake arms, bridging the gap between the pivots and is said to “reduce deformation and improve braking efficiency.” For me, the biggest difference of R8000 over 6800 is the shape of the brake lever. The curve for your index finger is more pronounced and if, like me, you like to wrap your finger around the bar when on the hoods then you'll find it very comfortable. If you're fitting a new derailleur, you should definitely apply assembly grease on the screw thread of the derailleur pad. You can find our selection of assembly greases here.

When I press the cage gently with my finger to bring it forward, the noise disappears and the chain no longer seems to "vibrate" above the top pulley (you can watch the difference on the video, looking the chain just above the top pulley). Thoroughly wiggling it in a workstand, the tension of the cage pivot feels a little bit stronger than the previous generation, which should help to keep things quiet on rougher terrain. You will probably also need to install another derailleur cable to get the derailleur working. You can find these cables here. As part of the trip to Spring Valley, MN, I joined other journalists in racing the Almanzo 100 gravel race on an Allied Alfa All-Road bike equipped with the new Di2 Ultegra RX805 rear derailleur. By chance, I got the opportunity to experience the gravel life with both a non-clutch Dura Ace R9150 rear derailleur and the new RX805. The Ultegra derailleur is designed with Shimano's Shadow-Link design. As a result, the derailleur is located further under the cassette, so that the derailleur is better protected and shifts faster. Even in bad conditions, this derailleur will still shift well!

The latest iteration of the Shimano Ultegra groupset, R8000, offers a huge leap in performance and aesthetics over the previous 6800 version which makes it an absolute joy to use. I can't see any reason to spend more on a groupset – the only question is whether it does enough to justify its price against its cheaper sibling, 105. I think i end up with about 4-5mm of gap between upper pulley and the 30T cog - If this shift has i grinding noise, i found that the gap is too small and need another 1mm or 2 to become noisy but with no "grinding" (and i don´t meen grinding noise like bad indexing - its different på grinding, more like the upper pulley hitting the cog type of sound)