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  • Shimano - Ultegra Di2 RD-6870 Rear Derailleur - Gray

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  • Shimano - Ultegra Di2 RD-6870 Rear Derailleur - Gray

Shimano Ultegra Di2 RD-6870 Rear Derailleur

sale from $159.95 $228.9928% Off

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    • Gray, Short Cage
      sale $159.95
    • Gray, Mid Cage
      sale $169.98
    5510

    10 Reviews

    Details

    A close second.

    Shimano’s Ultegra Di2 RD-6870 Rear Derailleur features much of the same level of performance as the Dura-Ace group without the podium-topping price tag. Taking its cue from the Dura-Ace 9070, the profile of the 6870 has been trimmed, making it leaner than the previous Ultegra Di2 rear mech. The 6870 Di2 rear now also has 11-speed shifting capability with sleeker, more professional-looking wiring and a mid-cage version that can accommodate a 32t cog in the rear.

    Shimano’s electronic shifting features E-Tube technology, which allows you to customize shifting speed and even program how many gears the rear derailleur shifts through when holding the shift button down. Finally, the 6870 rear derailleur has built-in crash protection. In the event of an accident, the rear mechanism will actually compress and tuck away.

    • Slimmer profile
    • 11-speed shifting capability
    • Mid-cage accommodates a 32t cog in the rear
    • E-tube technology
    • Built-in crash protection
    • Item #SHI0657

    Tech Specs

    Material
    aluminum
    Claimed Weight
    254 g
    Recommended Use
    road cycling, cyclocross
    Manufacturer Warranty
    3 years

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?

    Nice!!

    • Familiarity: I've put it through the wringer

    I've had the 6770 and now this 6870 and the work just like they should, quite, fast and precise. The 6870 is much smaller than the previous 10 speed 6770, the cable hides better too since the exit port come in the back between it and the seat tube. Don't spend extra for Dura-Ace, unless you get it at the same price, Ultegra is just like dura Dura-Ace, just a few grams heavier, diet for a week and your there.

    Durable & Precise

    • Familiarity: I've put it through the wringer

    I've been extremely impressed with the performance of the Ultegra Di2 rear derailleur. I've logged considerable miles off road on my gravel bike, and while it's been banged around a bit, it hasn't missed a beat. It still delivers precise, quick shifts every time.

    Durable & Precise

    Reliable

    • Familiarity: I've put it through the wringer

    I purchased a bike with Ultegra Di2 about a year ago. It was my first foray into electronic shifting and it's just flat out reliable. The batteries last forever and you get quality dependable shifting. In the year that I've had it, I have had zero hickups.

    Sticking with it!

    • Familiarity: I've put it through the wringer

    Building a new bike is always exciting and it's always tempting to try new things. The drivetrain decision was particularly easy this time however, after my previous experience with Ultegra Di2. The light weight and sexy lines of the Dura Ace Di2 group are indeed tempting, but for the cost you can't go wrong with the Ultegra. I have had exactly :::zero::: issues with my previous group other than problems I have inflicted (read: derailleurs are not-crash-proof). This also makes the Ultegra a great option if you race, where close quarters and periodic pavement sampling are a fact of life.

    Works great, easy to install

    • Familiarity: I've put it through the wringer

    I bought this as part of an upgrade to 11-speed for my Trek Domane. Installing the derailleur was the easiest part of the installation. I got the medium cage because I wanted to use a 32-tooth cog on my cassette.

    The derailleur was very easy to install. I don't have the special tool Shimano recommends for disconnecting and connecting the Di2 wire to the derailleur, but I did it easily with my fingers. I disconnected and unbolted the old derailleur and bolted on the new one. I connected the wire, and tested it - it worked immediately.

    After putting on a new 11-speed chain, I ran through all the gears and it worked right away. Adjusting the Di2 is simple, first the limit screws and then the shifters. All 11 gears worked immediately, and the derailleur is fast and quiet. I've used it a lot on steep hills and on the flats, and it works like Di2 should - accurate, fast, and quiet.

    Flawless shifting, great value!

    • Familiarity: I've put it through the wringer

    I have been riding a full Ultegra Di2 setup for more than a year and I am never going back to mechanical if I can help it! Why? Perfect shifts, front and rear, easy setup, expandability (currently using the

    Flawless shifting, great value!

    consistent & reliable shifting

      i'm running the 6770 on both of my road bikes and i love how effortless the shifting is. no missed shifts, no adjustments for cable stretch/fatigue that often results in chain rattle. i have > 2,500 miles on these derailleurs and they have been very reliable, even in long rainy rides. battery life is sufficient for several months of shifting between charges. micro adjustment makes dialing in various/different cassettes very easy to do, even on the fly. i will never go back to mechanical.

      I am currently running Ultegra 6770 Di2 10 speed drivetrain. Can I convert to the newer 11 speed by changing to a Ultegra 6870 rear and Front derailleur, cassette, and chain or will I need the new junction box too?

      One bike mechanic told me that you need to replace the brake shifters as well because the 10-speed shifter only accommodates 10-speeds. Plus, there's the question of whether your old Di2 has an external battery that you'd like to replace and make it internal. In that instance you'd need wiring, the internal battery and a junction box too. One other potential issue is whether your rims can accommodate 11 speeds. I discovered that not all 10-speed rims can accommodate 11-speeds.

      I am currently running Ultegra Di2 10 speed drivetrain. Can I convert to newer 11 speed by changing rear derailleur, cassette, and chain or will I also need to change shifters?

      Best Answer

      Bill,



      Ideally, you want the entire drivetrain to be Di2 but you can make do with rear derailleur, cassette, and chain. The front shifting won't be perfect, but it will work. Shifters, Wires, and battery don't need to be updated but you may need to plug them in for a firmware update.