{"product_id":"supersprox-stealth-rear-sprocket-ktm-husqvarna-gasgas-rst-990-orange","title":"SuperSprox - Stealth Rear Sprockets - Orange","description":"\u003ch1\u003eSuperSprox Orange Stealth Rear Sprockets for KTM, Husqvarna \u0026amp; GasGas\u003c\/h1\u003e\n\u003cp data-path-to-node=\"1\"\u003e\u003cspan\u003eThe Supersprox Stealth Rear Sprocket (RST-990 series) is a hybrid-material 520 drive sprocket engineered for off-road,\u003c\/span\u003e\u003cspan\u003e cross-country,\u003c\/span\u003e\u003cspan\u003e and motocross motorcycles.\u003c\/span\u003e\u003cspan\u003e Standard drive options present an inherent compromise:\u003c\/span\u003e\u003cspan\u003e 7075-T6 all-aluminum sprockets offer low rotating weight but wear out rapidly under abrasive mud and chain grit,\u003c\/span\u003e\u003cspan\u003e while solid steel sprockets offer high longevity at the cost of substantial unsprung rotating mass.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-path-to-node=\"2\"\u003e\u003cspan\u003eThe Stealth architecture resolves this trade-off by joining an induction-hardened,\u003c\/span\u003e\u003cspan\u003e high-carbon steel outer tooth ring to an aircraft-grade 7075-T6 aluminum inner carrier using permanent high-strength stainless steel rivets.\u003c\/span\u003e\u003cspan\u003e The outer steel teeth deliver up to three times the operating lifespan of an aluminum sprocket and resist chain hook formation under heavy throttle loads.\u003c\/span\u003e\u003cspan\u003e The CNC-machined 7075-T6 aluminum inner core reduces rotational mass by roughly 50% compared to a solid steel unit,\u003c\/span\u003e\u003cspan\u003e decreasing gyroscopic inertia to maintain light suspension action and crisp throttle response.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch4 data-path-to-node=\"3\"\u003eFeatures:\u003c\/h4\u003e\n\u003cul data-path-to-node=\"4\"\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,0,0\"\u003e\u003cb data-path-to-node=\"4,0,0\" data-index-in-node=\"0\"\u003eHybrid Bi-Metal Architecture:\u003c\/b\u003e\u003cspan\u003e Combines high-carbon steel outer teeth for extended wear resistance with a 7075-T6 aluminum carrier for reduced rotational mass.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,1,0\"\u003e\u003cb data-path-to-node=\"4,1,0\" data-index-in-node=\"0\"\u003eExtended Wear Life:\u003c\/b\u003e\u003cspan\u003e Delivers up to three times the service life of an all-aluminum rear sprocket under abrasive off-road mud and sand conditions.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,2,0\"\u003e\u003cb data-path-to-node=\"4,2,0\" data-index-in-node=\"0\"\u003eRotational Weight Reduction:\u003c\/b\u003e\u003cspan\u003e Approximately 50% lighter than a standard all-steel sprocket,\u003c\/span\u003e\u003cspan\u003e reducing unsprung inertia at the rear wheel.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,3,0\"\u003e\u003cb data-path-to-node=\"4,3,0\" data-index-in-node=\"0\"\u003eHigh-Strength Riveted Construction:\u003c\/b\u003e\u003cspan\u003e Outer ring and inner carrier are secured using patented inter-locking geometry and high-tensile stainless steel rivets.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,4,0\"\u003e\u003cb data-path-to-node=\"4,4,0\" data-index-in-node=\"0\"\u003eSelf-Cleaning Tooth Profile:\u003c\/b\u003e\u003cspan\u003e Machined mud grooves between teeth channel trail silt,\u003c\/span\u003e\u003cspan\u003e clay,\u003c\/span\u003e\u003cspan\u003e and sand outward from the chain rollers to minimize driveline tension spikes.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,5,0\"\u003e\u003cb data-path-to-node=\"4,5,0\" data-index-in-node=\"0\"\u003eCorrosion-Resistant Finish:\u003c\/b\u003e\u003cspan\u003e Anodized aluminum inner core with electro-plated protective coating on the steel tooth ring.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4 data-path-to-node=\"5\"\u003eWhat's in the Box:\u003c\/h4\u003e\n\u003cul data-path-to-node=\"6\"\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,0,0\"\u003e\u003cspan\u003e1x Supersprox Stealth 520 Rear Sprocket (RST-990 Series)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,1,0\"\u003e\u003ci data-path-to-node=\"6,1,0\" data-index-in-node=\"0\"\u003e(Note: Sprocket mounting bolts sold separately. Select required tooth count and inner carrier color from the variant dropdown before checkout).\u003c\/i\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eFitment:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ch4\u003e1991–2027 – KTM 125–500cc EXC-F, XC-W, XCF-W, XC, XC-F, SX, SX-F\u003c\/h4\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ch4\u003e2014–2027 – Husqvarna 125–501cc FE, TE, FX, TX, FC, TC\u003c\/h4\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ch4\u003e2021–2027 – GasGas 125–500cc EC-F, EC, EX-F, EX, MC-F, MC\u003c\/h4\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ch4\u003e2000–2014 – Husaberg 125–570cc TE, FE, FX\u003c\/h4\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4 data-path-to-node=\"7\"\u003eFitment Notes:\u003c\/h4\u003e\n\u003cul data-path-to-node=\"8\"\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"8,0,0\"\u003e\u003cb data-path-to-node=\"8,0,0\" data-index-in-node=\"0\"\u003eChain Pitch:\u003c\/b\u003e\u003cspan\u003e Standard 520 drive chain.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"8,1,0\"\u003e\u003cb data-path-to-node=\"8,1,0\" data-index-in-node=\"0\"\u003eMounting Pattern:\u003c\/b\u003e\u003cspan\u003e Standard KTM 6-bolt pattern (150 mm bolt circle diameter \/ 125 mm inner hub register \/ M8 countersunk bolt holes).\u003c\/span\u003e\u003cb data-path-to-node=\"8,2,0\" data-index-in-node=\"0\"\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"8,6,0\"\u003e\u003cb data-path-to-node=\"8,6,0\" data-index-in-node=\"0\"\u003eIncompatible Platforms:\u003c\/b\u003e\u003cspan\u003e Does \u003c\/span\u003e\u003cb data-path-to-node=\"8,6,0\" data-index-in-node=\"29\"\u003eNOT\u003c\/b\u003e\u003cspan\u003e fit KTM 690 Enduro \/ Husqvarna 701 Enduro \/ GASGAS 700 ES (larger 6-bolt hub pattern),\u003c\/span\u003e\u003cspan\u003e or KTM 790\/890\/1090\/1190\/1290 Adventure platforms.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"12\"\u003e\u003cb data-path-to-node=\"12\" data-index-in-node=\"0\"\u003eSprocket Bolt Torquing Technique:\u003c\/b\u003e\u003cspan\u003e Never tighten sprocket bolts from the bolt head side.\u003c\/span\u003e\u003cspan\u003e The countersunk Allen or Torx head should be held completely stationary with a bit while you tighten and torque the nut on the inside of the wheel hub flange.\u003c\/span\u003e\u003cspan\u003e Rotating the tapered countersunk bolt head against the sprocket chamfer can gall the aluminum recess and cause false torque readings.\u003c\/span\u003e\u003cspan\u003e Clean all hub threads,\u003c\/span\u003e\u003cspan\u003e use medium \/ blue \u003cspan style=\"text-decoration: underline;\"\u003e\u003cstrong\u003eSTUCK NUTZ\u003c\/strong\u003e\u003c\/span\u003e threadlocker on the threads,\u003c\/span\u003e\u003cspan\u003e and torque the M8 nuts to the factory specification of \u003c\/span\u003e\u003cb data-path-to-node=\"12\" data-index-in-node=\"506\"\u003e35 Nm (25.8 ft-lbs)\u003c\/b\u003e\u003cspan\u003e in a criss-cross star pattern.\u003c\/span\u003e\u003cspan\u003e Always replace worn locking nuts when mounting a new sprocket.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"13\"\u003e\u003cb data-path-to-node=\"13\" data-index-in-node=\"0\"\u003ePairing with New Chains:\u003c\/b\u003e\u003cspan\u003e Installing a new Supersprox Stealth rear sprocket on a worn or stretched drive chain will prematurely ruin the steel teeth.\u003c\/span\u003e\u003cspan\u003e As a drive chain stretches,\u003c\/span\u003e\u003cspan\u003e its pitch spacing increases,\u003c\/span\u003e\u003cspan\u003e concentrating the entire drive load onto the tip of a single sprocket tooth rather than distributing it evenly across the bottom of the tooth valley.\u003c\/span\u003e\u003cspan\u003e Always measure chain elongation across 20 links or install a new front countershaft sprocket and quality sealed 520 chain at the same time to maximize drivetrain longevity.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"14\"\u003e\u003cb data-path-to-node=\"14\" data-index-in-node=\"0\"\u003eGearing Changes \u0026amp; Chain Guide Clearance:\u003c\/b\u003e\u003cspan\u003e Moving up in tooth count (e.\u003c\/span\u003e\u003cspan\u003eg.,\u003c\/span\u003e\u003cspan\u003e swapping a stock 48T or 50T to a 51T or 52T for technical singletrack) shifts the rear axle forward in the swingarm swing block slots and increases the overall sprocket diameter.\u003c\/span\u003e\u003cspan\u003e Verify that the lower chain guide has adequate vertical and lateral clearance for the larger sprocket radius; on 51T and 52T sprockets,\u003c\/span\u003e\u003cspan\u003e lower chain guide wear blocks may need to be adjusted or set back to prevent the chain rollers from dragging heavily against the guide housing.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cbr\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0622\/5720\/1317\/files\/MADE_IN_CZECHIA.jpg?v=1744046246\" alt=\"\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003ePart Number: RST-990\u003cbr\u003e\u003cbr\u003e\u003c\/p\u003e","brand":"Supersprox","offers":[{"title":"48T","offer_id":51086536540325,"sku":"SPRSPRX-RST-990-48-ORG","price":101.0,"currency_code":"USD","in_stock":false},{"title":"49T","offer_id":51086536573093,"sku":"SPRSPRX-RST-990-49-ORG","price":101.0,"currency_code":"USD","in_stock":false},{"title":"50T","offer_id":51086536605861,"sku":"SPRSPRX-RST-990-50-ORG","price":101.0,"currency_code":"USD","in_stock":false},{"title":"51T","offer_id":51086536638629,"sku":"SPRSPRX-RST-990-51-ORG","price":101.0,"currency_code":"USD","in_stock":false},{"title":"52T","offer_id":51086536671397,"sku":"SPRSPRX-RST-990-52-ORG","price":101.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0622\/5720\/1317\/files\/SuperSprox_Rear_Sprocket_KTM_Orange_RST-990-ORG.png?v=1793691769","url":"https:\/\/www.tmbrmoto.com\/products\/supersprox-stealth-rear-sprocket-ktm-husqvarna-gasgas-rst-990-orange","provider":"TMBR MOTO","version":"1.0","type":"link"}