{"product_id":"shimano-grx-rd-rx827-di2-12-speed-rear-derailleur-shadow-es-for-51t-cassette","title":"Shimano GRX RD-RX827 Di2 12-Speed Rear Derailleur Shadow ES for 51T Cassette","description":"\u003cp\u003eThe Shimano GRX RD-RX827 GRX Di2 12-speed rear derailleur is engineered specifically for gravel and mountain biking enthusiasts who demand precision and reliability. Designed with Shimano’s gravel-specific ergonomics, it offers optimized gearing options tailored to tackle diverse terrains with confidence. Featuring the innovative Shadow ES technology, this derailleur provides a super low profile skid plate and an optimized slant angle, ensuring optimal clearance and protection during intense rides.\u003c\/p\u003e\n\n\u003cp\u003eThis model boasts a precise and clean wireless shifting system powered by an integrated on-board removable battery (BT-DN320 sold separately), which is cleverly protected within the linkage for durability. The crash recovery function absorbs impacts and automatically returns the derailleur to its original position, minimizing disruptions on the trail. Its dual spring chain stabilizer significantly reduces chain bounce on rough terrain, delivering more stable drive and seamless shifting performance.\u003c\/p\u003e\n\n\u003cp\u003eBuilt with cold forged wide alloy links and a fluorine-coated link pin bushing, the RD-RX827 combines lightweight construction with exceptional rigidity and longevity. The 13T solid pulleys and optimized tension system prevent excessive chain tension in low gears, while the tighter chain wrap design ensures reliable engagement with sprockets and prevents skipping even as components wear. Compatible with 10-51 tooth cassettes and specifically designed for 12-speed drivetrains, this rear mech is a top choice for serious riders seeking smooth, dependable performance in demanding conditions.\u003c\/p\u003e\n\n\u003ch3\u003eWhat It’s Good For\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eProviding precise and wireless shifting for 12-speed gravel and mountain bike drivetrains\u003c\/li\u003e\n  \u003cli\u003eMaintaining chain stability and reducing bounce on rough or uneven terrain\u003c\/li\u003e\n  \u003cli\u003eHandling impacts with crash recovery functionality that keeps the derailleur aligned\u003c\/li\u003e\n  \u003cli\u003eOffering durable, lightweight performance with cold forged alloy construction and fluorine-coated components\u003c\/li\u003e\n  \u003cli\u003eEnsuring smooth gear changes with tighter chain wrap and 13T solid pulleys\u003c\/li\u003e\n  \u003cli\u003eCompatibility with a wide range of cassette sizes, up to 51T\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat It’s NOT Good For\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eUse with drivetrains other than 12-speed systems\u003c\/li\u003e\n  \u003cli\u003eApplications requiring mechanical shifting instead of electronic Di2 technology\u003c\/li\u003e\n  \u003cli\u003eRiders who do not require advanced chain stabilizing features\u003c\/li\u003e\n  \u003cli\u003eScenarios where wireless shifting components or batteries are not supported or preferred\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs the battery included with the derailleur?\u003c\/strong\u003e\u003cbr\u003eThe Shimano GRX RD-RX827 features an integrated on-board removable battery, but the BT-DN320 battery is sold separately.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan this derailleur be used with mechanical shifting systems?\u003c\/strong\u003e\u003cbr\u003eNo, this model is designed specifically for Shimano’s Di2 electronic shifting system and is not compatible with mechanical setups.\u003c\/p\u003e","brand":"Shimano GRX","offers":[{"title":"SGS - long \/ Grey","offer_id":45735525515439,"sku":"RDRX827SGS","price":423.69,"currency_code":"GBP","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0654\/2003\/4223\/files\/rdrx827sgs.jpg?v=1768526419","url":"https:\/\/www.swinnertoncycles.co.uk\/products\/shimano-grx-rd-rx827-di2-12-speed-rear-derailleur-shadow-es-for-51t-cassette","provider":"Swinnerton Cycles","version":"1.0","type":"link"}