If you think wide range cassette adapters are just for mountain bikes, think again. Relic MTB showed off this 40-tooth cog that slips onto the back of a Shimano 10 or 11 speed cassette. It comes with an 16-tooth intermediate cog to replace the 15 and 17 usually found in the lower third of the cassette. But if you think that’s big…

This demo unit shifted from the stock cassette to the oversized one surprisingly smoothly, and it works because they’ve knocked off the Goat Link, which gives the chain the necessary space between the derailleur’s upper pulley and the cog…and allows for enough chain wrap.

It works with 10-speed cassettes with a 28t big cog, and 11-speed cassettes with up to a 32-tooth cog. Weight for all three parts is ~92g.

Just in case SRAM Eagle’s 50-tooth isn’t enough, there’s this 52-tooth cog. Like the Road 40T, it slips onto the back of a Shimano cassette and comes with a 16t intermediate cog and a spacer to go between the largest stock cog and the oversized piece.

System weight is 146g for all three parts with the 52-tooth cog, and there’s a 50-tooth cog kit that’s 2g less. Pricing wasn’t set, and the parts are promoted on their homepage but aren’t yet listed in the product section.



        • TheKaiser on

          nunya is kind of right, in that while the spacing is the same between cogs on 11spd road and MTB cassettes, the cassette body width is not the same. 11spd road had to go to a slightly wider cassette body, since the largest cog does not cantilever out over the spokes, as it does on a MTB. Having said that, MTB 11spd is the narrower of the 2, and could be used on a road cassette body with a spacer behind it, so there is compatibility in that direction, just not the other way around, so ThreeRingCircus was correct that a MTB 11-40 could be used.

        • dl on

          Exactly, on my commuter bike I’m running 1x with the XT 11-46 cassette using a Rival 1x RD. Everything works like a charm.

      • Duster13 on

        huh??? You can run an 11-40 using shimano di2 road shifters with xtr di2 front and rear derailleur and an str 11-40 cassette. Same thing with Sram mechanical road shifters.

  1. King County on

    I agree with ‘BMX”, that there is always a triple, but for the guy that has a dedicated double group / no triple option, this is for him. I am not that guy, but someone is out there that is loaded up for touring, has his kid on a baby seat, dog in a trailer, …bbq,sink, etc, etc..

  2. Mr. P on

    Otherwise known as the “I quit!” gear.

    As suffering increases on steep climb and the donuts catch up with you
    – shift into the “I quit!” gear
    – ride to side of road
    – throw bike off cliff

    • whatever on

      Yeaaaaa, a bike snob. I bet you haven’t won a Tour de France or Giro Italia, therefore you are not worthy. See how easy it is to pass judgement.

      Not everyone is 20-25 and 140 pounds that ride 5 days a week. Plus many people don’t have the genetics. Frankly, I have better things to do than to be consumed by one activity, or be defined in any way by that activity.

      Beyond all that, a company wants me to give them my money, then said company needs to give me something I want. And if that means a very low gear, then guess what…….

      • Rider X on

        I was surfing BR and MR P was like,
        Real cyclists climb hills in 42 small chain ring and straight block cassette
        And I’m, like, “yeah, whatever!”

        Cause this is my
        United States of Whatever!

      • boo on

        on 32×34 ive a hard time finding stuff i cant climb without reserve and i climb steep stuff. i basically go 32 for mtb style steep loose stuff on my cx. im 20% bodyfat male.. i could not use 40×34 i dont think.

        tldr try 32×34 first

    • Duster13 on

      Yeah, I love all the clowns that think they can ride up anything with an 11-27 and then when they get to any type of inclination that “spin” their crank at about 30 rpm’s like you. hahaha

  3. Dude on

    Make a 34, (35?), or 36 to fit my existing 11-32 gravel bike setup and I’d consider it… 40 is maybe a jump too far. At least for me. If I’m gonna need a 40 in the back, I’m taking the MTB out.

    • Rod Diaz on

      Dude – I am running an 11-36 SRAM cassette on an 11 speed Shimano hydraulic brake system. Front is 46-36.

      No issues, I didn’t even need to reverse the B-screw to clear the larger cog. I know this exceeds both the Shimano deraileur specs and the notification on SRAM that such a derailleur is only for their 1X system. I use a KMC chain now, but it worked with the old Ultegra one as well. Give it a try, maybe?

  4. fred on

    working on my prototype 29er rim with integrated 210t cog. 1x, 2x, and 3x compatible for your various drivetrain setups. possible 27.5 version in the works.

  5. Ed Ng on

    No need for this nonsense if you’re running SRAM on your road bike–a GX 2×10 long cage has the take-up to run a 50/34 compact double with as wide range as 11-42 just fine and you don’t even need to faff with a RoadLink. The GX 2×10 long cage will even work on an 11-speed cassette/2×11 bike because the 11-speed shifter will ensure it moves the right amount between cogs out back as all of the SRAM Exact Actuation stuff is cross-compatible (hence why the SRAM 11-speed MTB stuff, which is X-Actuation, DOESN’T jive with the rest). I’ve run a SunRace 11-40 cassette with 50/34 rings on a road bike exactly this way in the past by using the GX 2×10 long cage RD. I decided to ditch the double entirely with my new bike and run Rival 1 Long Cage with CS-M8000 11-46 cassette and a narrow-wide direct mount 44T oval and I get all the range I ever needed (I don’t tend to spin as hard as possible down descents, so it’s not like I am missing the 50×11).


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