K-Edge Long Cage Derailleur Conversion for Shimano Di2 Road

K-Edge Long Cage Derailleur Conversion for Shimano Di2 Road

K-Edge Long Cage Di2 Derailleur Conversion

Note:  K-Edge has discontinued this product and we can no longer provide this service.  This being said, if you reach out, we’re happy to talk to you about other newer options that provide similar functionality.

Here in Vermont we have a lot of mountains (no kidding!), and roads that go up and over those mountains. Gearing is thus a major concern for many of our clients.  From items like long cage derailleur conversions to wide range aftermarket cassette cogsJ-Tek pulleys and Wolf Tooth RoadLinks, we work diligently to be aware of the latest options for a variety of drivetrains and how well they work.

One of the most common requests for lower gearing we get has been for Shimano’s Di2 system.  While the latest generation Ultegra 8020 and 8070 goes to a 34T large cassette cog out of the box (and we’ve seen more than a few people run 36T), Shimano’s previous two generations of components were not so generous in their gearing. Shimano’s two generations of Dura Ace Di2 road rear derailleurs (7970 and 9070), and the first generation of Ultegra Di2 (6770), could only safely be used with cassettes equipped with a largest cog of 28 teeth. While you can read on-line about people getting them to work with 30 teeth, using some sort of jiggery-pokery, these usually only work under some limited conditions and the risk of the derailleur being ripped off the bike accidentally increases markedly. Ultegra 6870 Di2 officially increased the cassette capacity to 30 teeth and I have had good luck with cassettes up to 32 teeth.  However, this may still not be as low as you want and thus you are out of luck putting low gearing on the previous two generations of Di2 components. K-Edge to the rescue…

K-Edge has developed a replacement rear derailleur pulley cage for 6870, 6770, 7970 and 9070 Di2 rear derailleurs that can accommodate cassettes up to 36 teeth. I wrote about this conversion at https://fitwerx.com/index.php?s=K-Edge, and we have had this conversion performed by K-Edge for many clients to date.

One limitation of the K-Edge Long Cage Conversion Kit was that the derailleur had to be shipped to K-Edge and thus the turn-around for this conversion was 2 to 3 weeks. Given the delay, it was not something we could offer on a “while-you-wait” basis. Today, we can do the K-Edge Long Cage Conversion Kit in-house; send us your derailleur and we can install the kit and send it back to you.  We usually install and send back derailleurs within 48 hours of receiving them.

If you have an older Shimano Di2 system and want to lower gearing, we can now take care of you in-house by providing a K-Edge long cage derailleur conversion to your existing rear derailleur or supplying a new longer cage rear derailleur.  Contact Us and start spinning up those hills with (relative) ease using a K-Edge long cage derailleur conversion!

About Ian

From first time riders to Olympians, Ian has helped thousands of athletes achieve their cycling and triathlon goals. Ian develops much of the Fit Werx fitting and analysis protocols and is responsible for technology training and development. He is regarded as one of the industry leaders in bicycle fitting, cycling biomechanics and bicycle geometry and design. He is dedicated to making sure the Fit Werx differences are delivered daily and provides Fit Werx with corporate direction and is responsible for uniting our staff and initiatives.

Find out more about Ian Here


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3 Responses to K-Edge Long Cage Derailleur Conversion for Shimano Di2 Road
  • David Maxwell

    I have been running a K-Edge long cage on my di2 Dura ace 9070 for over 5 years. I am currently running with a KCNC 11-40 cassette and Absolute Black 46-30 chainrings, it works really well on my gravel bike. I think the quality of all of the components in this set-up have given it longevity.

  • Dean

    Can you guys still do this conversion to a Ultegra 6770 rear mech?

    • Ian

      You can pick-up a complete long cage mechanical MTB rear derailleur in combination with a conversion pulley system to work with a dropbar shifter for substantially less money. This has pretty much eradicated modification of the mechanical derailleurs. Also, the conversion kits today are electronic specific and usually don’t easily bolt to mechanical. Hope this helps!

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