{"product_id":"rk-racing-chain-gb420mxz-140-gold-140-link-lightweight-mx-racing","title":"RK Racing Chain GB420MXZ-140 Gold 140 Link - Lightweight MX Racing","description":"\u003cp\u003eOur review of the GB420MXZ-140 finds it aimed squarely at riders who demand a race-ready, non O-ring chain that sacrifices neither strength nor weight. The bottom line: this chain is for serious motocross racers running 50cc to 125cc open class bikes who want the lightest possible drive chain without giving up tensile strength. The combination of chrome-moly construction, oversized alloy pins and RK's HIT heat treatment delivers a tangible upgrade in durability and performance compared with many stock chains.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n \u003cli\u003e\n\u003cstrong\u003eChrome-moly construction:\u003c\/strong\u003e Provides high strength and fatigue resistance for repeated impacts and hard use on motocross tracks.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eSeamless rollers and bushings:\u003c\/strong\u003e Reduce friction and wear, helping the chain run smoothly and extend service life between replacements.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eOversized special alloy pins:\u003c\/strong\u003e Add shear strength where it matters most, improving reliability under aggressive acceleration and jumps.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eHIT heat treatment:\u003c\/strong\u003e RK's Heat Induction Transfer process hardens all components for better wear resistance and consistent performance over time.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eLightweight design:\u003c\/strong\u003e At roughly 1.76 lb, the chain lowers rotating mass, which benefits throttle response and handling on lightweight race bikes.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eHigh tensile rating:\u003c\/strong\u003e A maximum tensile strength of 5000 ft-lb gives confidence for professional level 50cc to 125cc competition.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThis chain is best for competitive motocross riders and racers running small-displacement open class bikes who need a non O-ring option that is both light and exceptionally strong. Mechanics and racers who prefer periodic relay-style maintenance will appreciate the clip master link and the chain's focus on peak performance rather than low-maintenance sealing.\u003c\/p\u003e\n\u003cp\u003eRiders who want a maintenance-free sealed chain or those on larger displacement machines should look elsewhere; the GB420MXZ is optimized for performance on 50cc to 125cc race bikes rather than street-focused longevity or O-ring lubrication retention.\u003c\/p\u003e\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n \u003cli\u003eOutstanding strength-to-weight ratio for improved acceleration and handling.\u003c\/li\u003e\n \u003cli\u003eDurable construction with heat-treated chrome-moly and special alloy pins for longer wear life.\u003c\/li\u003e\n \u003cli\u003eSeamless rollers and bushings smooth operation and reduce premature wear.\u003c\/li\u003e\n \u003cli\u003eGold finish that customers note looks great on many bikes while performing reliably.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n \u003cli\u003eNon O-ring design requires more frequent cleaning and lubrication than sealed chains.\u003c\/li\u003e\n \u003cli\u003eDesigned for smaller race classes, so not intended for larger displacement street bikes.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n \u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eGB420MXZ-140\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eSeries\u003c\/td\u003e\n\u003ctd\u003e420 Series\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eLinks\u003c\/td\u003e\n\u003ctd\u003e140\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003ePin length\u003c\/td\u003e\n\u003ctd\u003e15.7 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eMaximum tensile\u003c\/td\u003e\n\u003ctd\u003e5000 ft-lb\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e1.76 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eMaster link type\u003c\/td\u003e\n\u003ctd\u003eClip\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe GB420MXZ-140 is a focused racing chain that delivers elite strength in a very light package, making it a smart buy for 50cc to 125cc open class riders who prioritize performance over low-maintenance convenience. Its heat-treated chrome-moly build and oversized pins offer excellent durability for competitive use, giving strong value to racers seeking measurable improvements on track.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eIs this chain suitable for motocross racing?\u003c\/strong\u003e\u003cbr\u003eYes, it is built for motocross racers and rated for professional level 50cc to 125cc open class competition.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the chain use a master link and what type?\u003c\/strong\u003e\u003cbr\u003eThe GB420MXZ-140 uses a clip master link for assembly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow does the chain balance weight and strength?\u003c\/strong\u003e\u003cbr\u003eChrome-moly construction, oversized alloy pins and RK's HIT heat treatment provide a high tensile rating while keeping the chain light at about 1.76 lb.\u003c\/p\u003e","brand":"RK Racing Chain","offers":[{"title":"Default Title","offer_id":48655245738203,"sku":"B00BS8BZJ8","price":44.7,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/61ix4ac5POL._AC_SL1000_1aba67ab-aade-4f2d-b532-abe388b95656.jpg?v=1778552029","url":"https:\/\/gearmusthave.com\/products\/rk-racing-chain-gb420mxz-140-gold-140-link-lightweight-mx-racing","provider":"GearMustHave","version":"1.0","type":"link"}