RoadLink Tech Page

The RoadLink is a simple device that offsets the position of your 10 or 11 speed Shimano road derailleur to make it possible to run a wide-range cassette as large as 11-40!   It is an ideal solution for riders looking to convert their road, gravel, cyclocross, or commuter Shimano drivetrain bike to attain the simplicity and reduced weight of a single front chainring...and without giving up the gear range of a double.  It is also great for riders with double chainring bikes that want lower gearing for those ultra steep climbs. It does this by moving your derailleur to an optimal location for these wider range cassettes.  
Below, we will cover the Gear Range, Derailleur Capacity, Compatibility, Specs, and FAQs.....

Gearing Range Improvement:

Here is a plot showing what ranges the RoadLink enables. Note that the 1x setups with 11/40 cassettes have nearly the same range as the double setups, with the only downside being bigger jumps between the faster gears.  This might not be ideal for your Tuesday Night Worlds group ride, but it is something to consider for all-road or gravel!

Explanation of Derailleur Capacity:

As mentioned, the RoadLink moves Shimano 10 and 11 speed rear derailleurs to an optimal position for wide range cassettes.  What the RoadLink does NOT do is expand your derailleurs capacity, as that is a function of the derailleur mechanics.  What is capacity you ask?  Capacity is how much chain slack the deraileur cage can absorb measured in number of teeth.  To calculate the capacity you need for a given setup use the following formula:
(Biggest Chainring - Smallest Chainring) +(Biggest Cassette Cog - Smallest Cassette Cog)
The derailleur capacity is a specified number that Shimano publishes and here are some "typical" numbers (Ultegra).  Please consult the Shimano Tech page for exact capacity:
  • 28t total capacity for an SS (Short Cage) Ultegra rear derailleur
  • 37t total capacity for an GS (Medium Cage) Ultegra rear derailleur (not available in Dura Ace)
  • We have found the actual capacity to be about 2 teeth bigger than the published numbers, so 30 and 39 respectively in these cases
Example case 1:
I want to run an 11/36 cassette with my compact Dura Ace 9000 setup and 50/36 chainrings.  
Using the formula (50-36)+(36-11) = (14+25) = 39 so your short cage rear derailleur (only length offered in the Dura Ace Trim) cannot handle this amount of tooth change.  The Medium Cage (GS) Ultegra has roughly 39t of capacity so it would work in this setup!
Example case 2:
I want to run an 11-40 cassette with my Ultegra that has 46/36 chainrings (this is a classic touring/all road setup!) and a GS (medium cage) rear derailleur
Using the formula (46-36)+(40-11) = 10+29 = 39 so your Ultegra medium cage WILL work with this massive range setup!
Example case 3:
I want to run an 11/40 cassette with my compact Dura Ace 9000 setup in a 1x configuration (remember that Dura Ace only comes in a short cage version as of 2015-16)
Using the formula (50-50)+(40-11) = 0+29 = 29 so your short cage rear derailleur can handle this setup!

RoadLink General Compatibility:

  • 10s Cassette Compatibility:
    • 11-32: Not Required (medium cage rear derailleur works) 
    • 11-34: Single or Double Chainring
    • 11-36: Single or Double Chainring (front rings can be no more than 14 teeth different e.g. 50-36)
    • 11-40: Single or Double Chainring (front rings can be no more than 10 teeth different e.g. 46-36)
    • 11-42: Not Supported
  • 11s Cassette Compatibility:
    • 11-32: Not Required (medium cage rear derailleur works)
    • 11-36: Single or Double Chainring (front rings can be no more than 14 teeth different e.g. 50-36)
    • 11-40: Single or Double Chainring (front rings can be no more than 10 teeth different e.g. 46-36)
    • 11-42: Not Supported
  • Other Compatibility Notes
    • The RoadLink is compatible with ten- and eleven-speed Shimano road derailleurs and shifters.
    • The RoadLink mounts only to standard derailleur hangers.
    • Double chainrings are only supported with GS (medium cage) rear derailleurs
    • Triple chainrings are not supported (medium cage rear derailleurs cannot accommodate that big of a change)
    • Direct Mount-native frames are not supported.   
    • Roadlink does work with SRAM and Campy Drivetrains, but is optimized around Shimano.  See the FAQs below.
    • Due to the lack of a clutch mechanism on Shimano road derailleurs, secondary chain retention (front derailleur or chain device) may be needed, especially for rough- or off-road use.
    • Due to variations in derailleur hanger geometry, chainstay length, chainring size, B-screw adjustment, and suspension configuration, individual results will vary.
  • One final key note on compatibility is that there are some derailleur hangers that our out of Shimano's spec for the 7.9 dimension pictured below.  If your derailleur has an extra long "tang" you can file it down to this dimension to allow the RoadLink to fit.

RoadLink Specs:

RoadLink FAQs:

1.  Can I use a 10 speed mountain bike rear derailleur with road shifting?  - No, they are not compatible
2.  Can I put a medium cage Utegra Derailleur Cage on my Dura Ace rear deraileur?  - Yes you can and it effectively makes a Dura Ace Medium Cage rear derailleur.  Installation is fairly simple and you can buy this medium cage from a number of sources including your local bike shop.
3.  Can I use this to make an 11-42 cassette work?  - Not reliably across all bikes so we just say "No".
4.  Can I use the RoadLink with Campy? - The RoadLink is optimized for the Shimano road derailleur geometry.  That's not to say that it won't help with Campagnolo, but we haven't really quantified the effect on their derailleurs (but a truly optimal solution might place the derailleur in a slightly different spot). 
5.  Can I use the RoadLink with SRAM? - The Roadlink will work with SRAM but again, is optimized for Shimano.  Note that SRAM has other wide range road gearing options available too.