Just last November in Tapiei, SunRace showed us new 12-speed SRAM replacement derailleurs and cassettes. But apparently that was only the beginning, as they already have four more 1x rear derailleurs in the works with new revised 1x-specific geometry, plus a new 12-speed cassette that works on Shimano’s workhorse HG freehub body…

SunRace 1x horizontal parallelogram derailleur prototype

SunRace 12speed budget mountain bike 1x-specific horizontal parallelogram derailleur prototype

So why did SunRace introduce a line of 12-speed mountain bike derailleurs just last fall, only to supplant them with new designs claiming to be better just a few months later? Those MZ (with carbon cage) & MX (with alloy cage) derailleurs we saw in November still shared SunRace’s long-standing slant parallelogram design which works best on more narrow cog size ranges than current 1x cassettes. They were essentially just old SunRace 10 & 11 speed designs with a longer cage to fit a larger rear cog. But that older shifting geometry (that SunRace SunTour actually invented back in the 1960s) moves the lower knuckle of the derailleur down & in as it shifts up the cassette which does not tend to maintain consistent distance from derailleur pulley to cog when you factor in the necessary chain wrap for wide modern 1x gearing spreads.

So a new horizontal parallelogram design like on SRAM’s current X-Horizon derailleurs and the new Shimano M9100 XTR, allows better chain gap & wrap control plus more precise derailleur actuation.

SunRace 12speed budget mountain bike 1x-specific horizontal parallelogram derailleur prototype

So the new SunRace 12-speed design if for a 1x-specific derailleur meant to be a budget alternative to top Shimano & SRAM setups. This derailleur will be made available in four versions, two each that work with Shimano or SRAM shifters and cassettes, with either the same carbon pulley cage MZ option, or the alloy cage MX option.

SunRace told us pricing had not yet been officially set, but that the MX option should be slightly cheaper than an SLX derailleur, and the MZ just under XT pricing. Curiously, the Shimano compatible MX & MZ versions of the new derailleur will be available to consumers first, before any real thoughts of SLX or XT 1×12. Expect the Shimano style to arrive in October 2019. The SRAM compatible ones will be a couple of months later, still anticipated before the end of this year.

SunRace 11-51T Shimano HG compatible cassette

Following up on the 10-50 & 10-52 12-speed cassettes that SunRace introduced last fall as replacements for your SRAM cassette on XD drivers, now they will offer a Shimano compatible version as well. This new 11-51T Shimano replacement cassette fits on a standard HG freehub body and uses a standard lock ring.

The 11-51 cassette features steel cogs on a pair of aluminum carriers, dished in to allow them to extend up and over the tapering spokes of your rear wheel for that larger cog. While the gearing range is limited to an extent, the compatibility with almost every wheelset on the market is a big plus. The new cassette will be available in May with a pricetag of about $100. No word if the premium machined version that is made for Eagle will get a Shimano model as well.

The SunRace derailleurs and cassettes look like they are most likely to see application as lower-cost replacements when you damage or wear out the 1x 12 speed setup on your mountain bike. But SunRace offers shifters too, which means you could build up your own complete wide-range 1x MTB drivetrain at a fraction of the cost of the premium alternative.



    • jeffrey Leonard on

      With a high offset upper jockey pulley the derailleurs arent actually longer than early derailleurs that utilized a 36t on triples they tend to be shorter well that is for non shimano derailleurs that is.

  1. Dockboy on

    Is that derailleur as big as it looks? Holy heck, I think it’d have ground clearance issues if used with 26″ or smaller!

  2. Donald Trumpet on

    Yea after the rock riders leave their hangers hanging off some granite. Maybe some sense on front derailleur design will happen. I say bring back 3×9 with 11-36 cassettes with a 27-36-45. If that doesn’t work then do something about the muscles in your legs.

    • Eggs Benedict on

      I understand the need for taller gears at times, but 45-11, that’s yuge. How about a compromise, a 2X, 26-36 with an 11-40 cassette. Maybe someone already offers something like that.

    • Mark on

      I don’t want to sound like a zealot, but electronic drivetrains would also help. With a 2x or 3x setup, the electronics could keep you from shifting into the extreme gears, so you can go with an even shorter chain and shorter cage derailleur.

    • blahblahblah on

      yeah but 3X on a modern mtb with big tires and linkage suspensions you would end up with a massive q factor at the cranks, and i think that’s the only thing 1x is good for(provided you only use the middle 5-6 cogs)

    • antoine on

      You can buy allk the 3x stuff and 2x stuff you want. There are still plenty options out there. I know i love my 1X and wouls never go back to 2 or 3. 3 simply never worked on preper mtb sutff, Chain simply don’t stay on medium ring. Also big and small were really not that usefull. 2X has slightly better chain retention but you always end up on the wrong ring shiting all the time on track with short climbs and descent. Very frustrating.
      1X just does everything fine. Chainlind is better because there is no more cross chain.

      • Eggs Benedict on

        Knowing when and how to shift the front der doesn’t require mad skillz, just requires paying attention. And there most certainly is cross chaining on a 1X system. The chain retention issue must be with full suspension bikes. Because I’ve never experienced a problem with it, and I don’t use a clutch rear der. (actually mine has a clutch, I just shut it off).

  3. Growthmind on

    I think this is fantastic for consumers. We’ll have more options – keep buying SRAM or shimano at a premium or maybe buy SunRace or GX, etc. More options for consumer are good, and it keeps some pressure on the dominant companies to provide better quality and service. I may not ever buy SunRace, but I’ll benefit indirectly from what they do in the market.

  4. satanas on

    Two questions:

    1. What are the intermediate cogs on the 11-51 cassette?
    2. Is the shift lever a Rapidfire+ clone, or is there only the one lever? (Can’t tell much from the pix.)

  5. Tiago on

    Are there any planned road shifters for this? I’m waiting for a nice gravel’ish 1×12 mechanical setup for my next build.


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