{"product_id":"sunrace-cassette-mz903-12-speed-11-51t-black","title":"Sunrace Cassette Mz903 12 Speed 11-51T - Black","description":"\u003ch2 data-end=\"49\" data-section-id=\"2ycft4\" data-start=\"0\"\u003eSunRace Cassette MZ903 12 Speed 11-51T (Black)\u003c\/h2\u003e\r\n\r\n\u003ch3 data-end=\"66\" data-section-id=\"c32iwk\" data-start=\"51\"\u003eWhat Is It?\u003c\/h3\u003e\r\n\r\n\u003cp data-end=\"468\" data-start=\"67\"\u003eThe SunRace MZ903 is a wide-range \u003cstrong data-end=\"126\" data-start=\"101\"\u003e12-speed MTB cassette\u003c\/strong\u003e designed as a cost-effective alternative to Shimano and SRAM Eagle systems. It gives you a huge gear range (11–51T) for steep climbing and fast rolling sections, and it fits standard \u003cstrong data-end=\"363\" data-start=\"310\"\u003eShimano HG (Hyperglide) 8–11 speed freehub bodies\u003c\/strong\u003e, which is a big reason many riders choose it for 1×12 conversions.\u003c\/p\u003e\r\n\r\n\u003chr data-end=\"473\" data-start=\"470\"\u003e\r\n\u003ch3 data-end=\"491\" data-section-id=\"1iz91iu\" data-start=\"475\"\u003eKey Features\u003c\/h3\u003e\r\n\r\n\u003cul data-end=\"966\" data-start=\"492\"\u003e\r\n\t\u003cli data-end=\"556\" data-section-id=\"m4f1e\" data-start=\"492\"\u003e12-speed MTB cassette with wide 11–51T range (463% gear range)\u003c\/li\u003e\r\n\t\u003cli data-end=\"653\" data-section-id=\"11z2j27\" data-start=\"557\"\u003eCompatible with Shimano 12-speed drivetrains and many SRAM Eagle setups (derailleur dependent)\u003c\/li\u003e\r\n\t\u003cli data-end=\"726\" data-section-id=\"l3v4oz\" data-start=\"654\"\u003eFits standard Shimano HG 8–11 speed freehub (no Microspline\/XD needed)\u003c\/li\u003e\r\n\t\u003cli data-end=\"820\" data-section-id=\"1kdobv8\" data-start=\"727\"\u003eHybrid construction: steel cogs for durability + alloy largest sprockets for weight savings\u003c\/li\u003e\r\n\t\u003cli data-end=\"912\" data-section-id=\"viwr7v\" data-start=\"821\"\u003eShift-optimized tooth profiling for smoother gear transitions (“Fluid Drive Plus” design)\u003c\/li\u003e\r\n\t\u003cli data-end=\"966\" data-section-id=\"6k2wjp\" data-start=\"913\"\u003eCommon 11-13-15-17-19-21-24-28-33-39-45-51T gearing\u003c\/li\u003e\r\n\u003c\/ul\u003e\r\n\r\n\u003chr data-end=\"971\" data-start=\"968\"\u003e\r\n\u003ch3 data-end=\"991\" data-section-id=\"1yl5694\" data-start=\"973\"\u003eSpecifications\u003c\/h3\u003e\r\n\r\n\u003cul data-end=\"1374\" data-start=\"992\"\u003e\r\n\t\u003cli data-end=\"1025\" data-section-id=\"1oddvio\" data-start=\"992\"\u003eType: MTB Cassette (1×12 speed)\u003c\/li\u003e\r\n\t\u003cli data-end=\"1041\" data-section-id=\"exqiry\" data-start=\"1026\"\u003eRange: 11–51T\u003c\/li\u003e\r\n\t\u003cli data-end=\"1060\" data-section-id=\"1d1pkfj\" data-start=\"1042\"\u003eSpeeds: 12-speed\u003c\/li\u003e\r\n\t\u003cli data-end=\"1106\" data-section-id=\"3tmdnm\" data-start=\"1061\"\u003eFreehub: Shimano HG (8–11 speed compatible)\u003c\/li\u003e\r\n\t\u003cli data-end=\"1156\" data-section-id=\"1khdy2u\" data-start=\"1107\"\u003eCog layout: 11-13-15-17-19-21-24-28-33-39-45-51\u003c\/li\u003e\r\n\t\u003cli data-end=\"1295\" data-section-id=\"13x7qyu\" data-start=\"1157\"\u003eConstruction:\r\n\t\u003cul data-end=\"1295\" data-start=\"1175\"\u003e\r\n\t\t\u003cli data-end=\"1218\" data-section-id=\"kra8f2\" data-start=\"1175\"\u003eSteel smaller cogs (high wear resistance)\u003c\/li\u003e\r\n\t\t\u003cli data-end=\"1259\" data-section-id=\"v0o7g0\" data-start=\"1221\"\u003eAlloy larger cogs (weight reduction)\u003c\/li\u003e\r\n\t\t\u003cli data-end=\"1295\" data-section-id=\"pbw3ns\" data-start=\"1262\"\u003eAlloy spider carrier + lockring\u003c\/li\u003e\r\n\t\u003c\/ul\u003e\r\n\t\u003c\/li\u003e\r\n\t\u003cli data-end=\"1374\" data-section-id=\"t6p4yx\" data-start=\"1296\"\u003eWeight: ~510–580g depending on version\u003c\/li\u003e\r\n\u003c\/ul\u003e\r\n\r\n\u003chr data-end=\"1379\" data-start=\"1376\"\u003e\r\n\u003ch3 data-end=\"1389\" data-section-id=\"yntdlk\" data-start=\"1381\"\u003ePros\u003c\/h3\u003e\r\n\r\n\u003cp data-end=\"1710\" data-start=\"1390\"\u003e✔ Works with widely available Shimano HG freehubs (easy upgrade path)\u003cbr data-end=\"1462\" data-start=\"1459\"\u003e\r\n✔ Huge climbing range (51T bail-out gear is excellent for steep trails)\u003cbr data-end=\"1536\" data-start=\"1533\"\u003e\r\n✔ Generally cheaper than Shimano Deore\/SLX 12-speed cassettes\u003cbr data-end=\"1600\" data-start=\"1597\"\u003e\r\n✔ Solid durability thanks to mostly steel construction\u003cbr data-end=\"1657\" data-start=\"1654\"\u003e\r\n✔ Compatible with many Shimano 12-speed derailleurs\u003c\/p\u003e\r\n\r\n\u003chr data-end=\"1715\" data-start=\"1712\"\u003e\r\n\u003ch3 data-end=\"1725\" data-section-id=\"yncdlj\" data-start=\"1717\"\u003eCons\u003c\/h3\u003e\r\n\r\n\u003cp data-end=\"2075\" data-start=\"1726\"\u003e✖ Heavier than Shimano or SRAM higher-end cassettes\u003cbr data-end=\"1780\" data-start=\"1777\"\u003e\r\n✖ Shifting is slightly less “buttery” than Shimano Hyperglide+ systems\u003cbr data-end=\"1853\" data-start=\"1850\"\u003e\r\n✖ Wear rate can be faster under heavy riders or aggressive riding\u003cbr data-end=\"1921\" data-start=\"1918\"\u003e\r\n✖ Compatibility tuning can be sensitive (B-screw and derailleur setup matter a lot)\u003cbr data-end=\"2007\" data-start=\"2004\"\u003e\r\n✖ Not true HG+ ramping, so under load shifts can feel less refined\u003c\/p\u003e\r\n\r\n\u003chr data-end=\"2080\" data-start=\"2077\"\u003e\r\n\u003ch3 data-end=\"2109\" data-section-id=\"lom3wk\" data-start=\"2082\"\u003eWho Is It Suitable For?\u003c\/h3\u003e\r\n\r\n\u003cul data-end=\"2352\" data-start=\"2110\"\u003e\r\n\t\u003cli data-end=\"2156\" data-section-id=\"jtioyu\" data-start=\"2110\"\u003eMTB riders upgrading to \u003cstrong data-end=\"2156\" data-start=\"2136\"\u003e1×12 on a budget\u003c\/strong\u003e\n\u003c\/li\u003e\r\n\t\u003cli data-end=\"2196\" data-section-id=\"1blb3c5\" data-start=\"2157\"\u003eRiders without Microspline or XD hubs\u003c\/li\u003e\r\n\t\u003cli data-end=\"2250\" data-section-id=\"1lq6spu\" data-start=\"2197\"\u003eTrail riders needing a \u003cstrong data-end=\"2250\" data-start=\"2222\"\u003ewide climbing gear range\u003c\/strong\u003e\n\u003c\/li\u003e\r\n\t\u003cli data-end=\"2307\" data-section-id=\"1gqmowf\" data-start=\"2251\"\u003eE-bike riders wanting affordable replacement cassettes\u003c\/li\u003e\r\n\t\u003cli data-end=\"2352\" data-section-id=\"3bkvn7\" data-start=\"2308\"\u003eBike builders doing drivetrain conversions\u003c\/li\u003e\r\n\u003c\/ul\u003e\r\n\r\n\u003chr data-end=\"2357\" data-start=\"2354\"\u003e\r\n\u003ch3 data-end=\"2381\" data-section-id=\"10onbcu\" data-start=\"2359\"\u003eWho Should Use It?\u003c\/h3\u003e\r\n\r\n\u003cp data-end=\"2412\" data-start=\"2382\"\u003eThis cassette is ideal if you:\u003c\/p\u003e\r\n\r\n\u003cul data-end=\"2632\" data-start=\"2413\"\u003e\r\n\t\u003cli data-end=\"2474\" data-section-id=\"hr31kw\" data-start=\"2413\"\u003eWant \u003cstrong data-end=\"2474\" data-start=\"2420\"\u003e12-speed performance without changing your freehub\u003c\/strong\u003e\n\u003c\/li\u003e\r\n\t\u003cli data-end=\"2524\" data-section-id=\"86wcsa\" data-start=\"2475\"\u003eRide steep terrain and need a 51T climbing gear\u003c\/li\u003e\r\n\t\u003cli data-end=\"2568\" data-section-id=\"1fs88nc\" data-start=\"2525\"\u003eAre building or upgrading a mid-range MTB\u003c\/li\u003e\r\n\t\u003cli data-end=\"2632\" data-section-id=\"1rt7tgk\" data-start=\"2569\"\u003ePrioritize value and compatibility over premium shifting feel\u003c\/li\u003e\r\n\u003c\/ul\u003e\r\n\r\n\u003cp data-end=\"2767\" data-start=\"2634\"\u003eIt’s especially popular in South Africa-style trail conditions where durability + cost matter more than marginal shifting refinement.\u003c\/p\u003e\r\n\r\n\u003chr data-end=\"2772\" data-start=\"2769\"\u003e\r\n\u003ch3 data-end=\"2789\" data-section-id=\"1g7992f\" data-start=\"2774\"\u003eBottom Line\u003c\/h3\u003e\r\n\r\n\u003cp data-end=\"3118\" data-start=\"2790\"\u003eThe SunRace MZ903 11–51T is one of the best-value ways to run a modern 12-speed MTB drivetrain on a Shimano HG hub. It’s not as refined as Shimano Deore or SLX cassettes, but it delivers a massive gear range, solid durability, and wide compatibility at a much lower cost—making it a very practical upgrade or replacement option.\u003c\/p\u003e\r\n","brand":"SUNRACE","offers":[{"title":"Default Title","offer_id":46323332546782,"sku":"CS661Z","price":1985.0,"currency_code":"ZAR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1242\/8790\/files\/23778_b0a3502e2ef359e23d93e13ff69c0a7d.jpg?v=1780579055","url":"https:\/\/onlino-bicycle-shopco.shop\/products\/sunrace-cassette-mz903-12-speed-11-51t-black","provider":"Online Bicycle Shop","version":"1.0","type":"link"}