{"product_id":"moto-master-1210-2812-15t-front-countershaft-sprocket-for-yamaha-yz85-hardened-steel-428-chain","title":"Moto-Master 1210-2812 15T Front Countershaft Sprocket for Yamaha YZ85 — Hardened Steel 428 Chain","description":"\u003cp\u003e\u003cb\u003eMoto-Master — Elite Core Power Delivery and Hardened Steel Armor for Motocross Racing Mini-Cycles\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003eThe most common cause of sudden engine-to-wheel power drop on the track is rapid wear and grooving on the countershaft sprocket from high-RPM mini-cycle acceleration. Standard front gears suffer from a \"durability gap,\" where extreme torque loads from aggressive clutch drops cause teeth to warp, misaligning the drive chain and increasing frictional drag on the engine. The Moto-Master 1210-2812 Front Countershaft Sprocket solves this drivetrain fatigue pain point for youth racing pilots by utilizing premium, top-grade hardened steel engineered to manage continuous high-RPM stress without losing its flawless geometric profile.\u003c\/p\u003e\n\u003cp\u003eThis isn't an ordinary front drive gear; it is a weight-optimized racing component engineered for seamless System Synergy with your mini-bike's transmission output shaft and final drive loop. Formed via precision machining with zero grinding imperfections, this 15-tooth sprocket sports a natural steel finish built to resist heavy friction and surface galling under severe conditions. By preserving factory-accurate tooth geometry, it creates a Matched Performance interface with your drive chain, maximizing power transfer straight to the rear wheel while maintaining a true Factory Quality standard from the gate drop to the checkered flag.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003e1210-2812 (15 Tooth Front Countershaft Sprocket):\u003c\/b\u003e A top-grade hardened steel front drive sprocket designed for 428 pitch configurations to deliver custom gearing setups on high-revving mini platforms.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eTop-Grade Hardened Steel Alloy:\u003c\/b\u003e Crafted from industrial-strength premium steel that undergoes specialized heat treatment to ensure excellent core density and resistance to tooth wear.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003e428 Chain Size Optimization:\u003c\/b\u003e Machine-cut to seamlessly interface with standard high-performance mini motocross 428 chains, eliminating tight links and rough rolling resistance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eConcentric Precision Machining:\u003c\/b\u003e Built to perfect geometric circular specs without stamping flaws, eliminating countershaft vibration and securing consistent case clearance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eDebris Shedding Mud Grooves:\u003c\/b\u003e Engineered with deep, clear relief channels that expel packed sand and clay instantly, stopping chain jumping during wet track conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eHigh-RPM Stability:\u003c\/b\u003e Hardened spline pathways lock firmly onto the Yamaha countershaft with minimal tolerance play, protecting output shaft splines from expensive stripping.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cb\u003eMoto-House MX Pro Tip:\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003eWhen swapping out your mini-racer's countershaft sprocket, always double-check the wear on the rest of the drivetrain assembly. To secure a high-level Matched Performance and shield your fresh steel gear from accelerated rounding, never wrap an old, loose chain around a brand-new sprocket. We strongly advise replacing the front gear, rear sprocket, and a high-tensile 428 drive chain at the same exact time. Clean the countershaft splines completely, apply a light coat of grease, and ensure a new factory lock washer or snap ring is correctly crimped into place.\u003c\/p\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; text-align: left;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #f2f2f2;\"\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #ddd;\"\u003eYear\u003c\/th\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #ddd;\"\u003eMake\u003c\/th\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #ddd;\"\u003eModel\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e2002 - 2025\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003eYamaha\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003eYZ85\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003e2022 - 2025\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003eYamaha\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #ddd;\"\u003eYZ85 LW (Large Wheel)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eFAQ Questions\u003c\/h3\u003e\n\u003cp\u003eQ) \u003cb\u003eWill a 15-tooth front sprocket provide my YZ85 with more acceleration or higher top-end speed?\u003c\/b\u003e\u003cbr\u003eA) Going to a 15-tooth front sprocket (adding teeth over stock) will significantly increase your mini-cycle's top-end speed and smooth out the power delivery across long track sections, making it ideal for fast, wide-open outdoor tracks.\u003c\/p\u003e\n\u003cp\u003eQ) \u003cb\u003eDoes this countershaft sprocket require a specialized racing chain?\u003c\/b\u003e\u003cbr\u003eA) No, this sprocket is precisely cut to work with any high-performance 428-pitch non-sealed or sealed motocross racing chain standard to the Yamaha YZ85 platform.\u003c\/p\u003e\n\u003cp\u003eQ) \u003cb\u003eDoes this kit include a replacement lock washer and countershaft nut?\u003c\/b\u003e\u003cbr\u003eA) No, this includes the individual 15-tooth hardened steel front sprocket only. We highly advise reusing your factory hardware or replacing the locking tabs with OEM parts if they show signs of bending stress.\u003c\/p\u003e\n\u003cdiv style=\"margin-top: 20px; text-align: center;\"\u003e\n\u003ca href=\"\/search?q=Moto-Master+Front+Sprocket\"\u003eMoto-Master Front Sprockets\u003c\/a\u003e | \u003ca href=\"\/search?q=Yamaha+YZ85+15+Tooth+Front+Gear\"\u003eYamaha YZ85 15T Gears\u003c\/a\u003e | \u003ca href=\"\/search?q=Moto-Master+1210-2812+Collection\"\u003eMoto-Master 1210-2812 Collection\u003c\/a\u003e\n\u003c\/div\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cb\u003eMoto-House MX – Choice of Champions\u003c\/b\u003e – is located in Clermont\/Montverde, FL. We are the best motocross shop in Central Florida with lightning-fast shipping.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"MOTO-MASTER","offers":[{"title":"Default Title","offer_id":44495827533907,"sku":"610171115","price":26.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1754\/5421\/files\/5569944.png?v=1776227626","url":"https:\/\/motohousemx.com\/products\/moto-master-1210-2812-15t-front-countershaft-sprocket-for-yamaha-yz85-hardened-steel-428-chain","provider":"Moto-House MX","version":"1.0","type":"link"}