{"product_id":"rk-racing-chain-420-series-non-o-ring-racing-chain-108-link-gold-lightweight-high-tensile-for-50-125cc","title":"RK Racing Chain 420 Series Non O‑Ring Racing Chain — 108-Link Gold, Lightweight High‑Tensile for 50–125cc","description":"\u003cp\u003e\u003cstrong\u003eRK Racing Chain GB420MXZ-108 is a purpose-built, ultra-lightweight non O-ring 420-series racing chain engineered for 50–125cc motocross competition.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eDesigned for riders who demand maximum strength with minimal weight, the GB420MXZ blends chrome‑moly construction, seamless rollers and oversized alloy pins with RK’s proprietary heat-treatment process. The result is a high-tensile, race‑focused chain that balances durability and low mass for precise power delivery in off‑road and MX\/SX conditions. This SKU ships as a 108-link gold chain and includes a clip-style master link for fast installation.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this chain deliver strength without extra weight?\u003c\/h3\u003e\n\u003cp\u003eThe GB420MXZ uses chrome‑moly steel components—seamless rollers, bushings and specially alloyed, oversized pins—that are all heat-treated with RK’s HIT (Heat Induction Transfer) process. That combination increases fatigue resistance and tear strength while keeping the overall mass low, letting the chain handle high loads without adding unnecessary weight.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMaximum tensile strength: rated to 5000 pounds\/feet\u003c\/li\u003e\n  \u003cli\u003eLightweight: approximately 1.76 pounds per 100 links\u003c\/li\u003e\n  \u003cli\u003eOversized alloy pins and seamless rollers for reduced failure points\u003c\/li\u003e\n  \u003cli\u003eHIT heat treatment for improved hardness and wear resistance\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhich bikes and race classes is the GB420MXZ-108 best suited for?\u003c\/h3\u003e\n\u003cp\u003eThis 420-series chain is tuned for small‑bore motocross and supercross machines where low rotating mass and high tensile strength matter most. It’s ideal for professional and club racers running 50cc through 125cc open-class off‑road bikes and for street machines up to 150cc where non O-ring chains are specified.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDesigned for 50cc–125cc off‑road racing\u003c\/li\u003e\n  \u003cli\u003eAcceptable for street use up to 150cc (per RK guidance)\u003c\/li\u003e\n  \u003cli\u003e108-link length fits many common sprocket setups; can be shortened as needed\u003c\/li\u003e\n  \u003cli\u003eMaster link supplied as a clip-style connector for quick fitting\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the key service and sizing details I should know?\u003c\/h3\u003e\n\u003cp\u003eChain pitch center-to-center measures 12.7 mm with a pin length of 15.7 mm, delivering 24.0 links per foot. Wear-life index and longevity depend on riding conditions and maintenance—proper lubrication and tensioning lengthen service, while abrasive race environments will reduce usable life.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePin-to-pin center (pitch): 12.7 mm\u003c\/li\u003e\n  \u003cli\u003ePin length: 15.7 mm\u003c\/li\u003e\n  \u003cli\u003eLink count: 108 links included\u003c\/li\u003e\n  \u003cli\u003eWear life index: rated up to 300 under ideal conditions\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho this is for: The RK GB420MXZ-108 is aimed at dedicated motocross and supercross riders, mechanics building race setups for 50–125cc classes, and lightweight-focused tuners who prioritize tensile strength and reduced rotating mass over sealed-ring convenience. If you compete or push a small-bore bike hard in off-road conditions and need a robust non O-ring chain that’s easy to service and quick to install, this model is a strong candidate. Note: RK’s sealed-ring warranty applies to non-racing street use, but RK does not warrant chains used in competitive racing.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I use the GB420MXZ-108 on a 125cc motocross bike?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The GB420MXZ-108 is optimized for 50–125cc off-road racing and handles the loads typical of 125cc motocross machines.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this chain come with a master link and what type is it?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: It includes a clip-style master (connecting) link for quick installation and removal during maintenance.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"RK Racing Chain","offers":[{"title":"Default Title","offer_id":48079821340830,"sku":"B00BT78RJ4","price":65.05,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/rk-racing-chain-gb420mxz-front-packaging.jpg?v=1785771715","url":"https:\/\/northtrailauto.ca\/products\/rk-racing-chain-420-series-non-o-ring-racing-chain-108-link-gold-lightweight-high-tensile-for-50-125cc","provider":"North Trail Auto","version":"1.0","type":"link"}