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…Advertisement
SunRace 1x 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 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 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.