{"product_id":"shimano-sm-rt66-6-bolt-disc-brake-rotor","title":"Shimano SM-RT66 6-Bolt Disc Brake Rotor 160mm \/ 180mm","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003eThe correct rotor for most Shimano disc brake builds. Reliable, proven, universally compatible.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003eThe SM-RT66 is Shimano's SLX-grade 6-bolt disc brake rotor: the standard against which most other rotors in this price range are measured. Shimano's SM-RT66 6-bolt disc brake rotors deliver consistent stopping power in all riding conditions, with a reliable anti-loosen plate construction that makes for quick and secure installation. It is the rotor we specify on Evercoast Passage builds and the rotor we stock for our eBike brake upgrade program. Not because it is the most expensive option available, but because it is the correct specification for the applications we build for. \u003cspan class=\"inline-flex\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003ePrecision-Cut Stainless Steel Braking Surface\u003c\/strong\u003e Precision cut and drilled stainless steel braking surface improves pad clearing in muddy conditions whilst aiding cooling under high load. The cutouts are not decorative: they channel debris away from the pad contact zone and increase the surface area exposed to airflow, which reduces heat buildup under sustained braking. In Vancouver conditions where mud, grit, and water are present for eight months of the year, this matters. \u003cspan class=\"inline-flex\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003eResin and Metal Pad Compatible\u003c\/strong\u003e Unlike the SM-RT56 which is restricted to resin pads, the SM-RT66 is resin and metal pad compatible, giving riders the flexibility to run their compound of choice or switch seasonally between quieter resin for dry conditions and more powerful sintered metal for wet and muddy riding. One rotor works with both pad types: no need to match your rotor specification to your pad choice.\u003cspan class=\"inline-flex\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003eUniversal 6-Bolt Compatibility\u003c\/strong\u003e The 6-bolt ISO mount is the most widely used rotor mounting standard in the world. Compatible with all standard 6-bolt hubs, including the Novatech 791SB and 792SB hubs we use on the Passage and Passage Pro builds. No lockring tool required, no proprietary installation process. Six T25 Torx bolts, torqued to 4-5 Nm, and the rotor is done.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003eWhy 180mm for eBikes\u003c\/strong\u003e The 160mm rotor is the correct specification for standard road and gravel builds where weight and caliper clearance are the primary considerations. For hub motor eBikes, which typically weigh 25–30 kg with a rider aboard, 180mm is the correct specification. The larger swept area increases stopping power and, critically, increases the thermal mass available to absorb heat under repeated hard braking in stop-and-go commuting. A smaller rotor on a heavy eBike runs hotter, which causes brake fade precisely when you need stopping power most. When we install brake upgrades on eBikes at the Evercoast workshop, 180mm is our standard rotor recommendation regardless of what the bike shipped with.\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch4 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\"\u003eSpecifications\u003c\/h4\u003e\n\u003cdiv class=\"overflow-x-auto w-full px-2 mb-6\"\u003e\n\u003ctable class=\"min-w-full border-collapse text-sm leading-[1.7] whitespace-normal\"\u003e\n\u003cthead class=\"text-left\"\u003e\n\u003ctr\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eFeature\u003c\/th\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eModel\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eSM-RT66\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eSeries\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eShimano SLX\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eMount\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e6-bolt ISO (P.C.D. 44mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eMaterial\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eStainless steel — one-piece construction\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003ePad Compatibility\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eResin and metal \/ sintered\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eAnti-Loosen Plate\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eWeight — 160mm\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e114g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eWeight — 180mm\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e154g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch4 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\"\u003eSize Guide\u003c\/h4\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003e160mm: \u003c\/strong\u003eroad, gravel, and cyclocross builds on standard bicycles. The correct size for Passage and Passage Pro complete builds with Shimano GRX or CUES groupsets. Fits most standard post mount and flat mount calipers without an adapter.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003e180mm: \u003c\/strong\u003eeBike brake upgrades, heavier riders, loaded touring, and riders who want more stopping power and better heat management. Our standard recommendation for all hub motor eBike brake upgrades. Requires a post mount adapter when used with standard post mount calipers, adapter available separately.\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch4 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\"\u003eCompatibility Notes\u003c\/h4\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003eSold individually: \u003c\/strong\u003eone rotor per listing. A complete front and rear build requires two rotors.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003e6-bolt hubs only: \u003c\/strong\u003enot compatible with centre-lock hubs. For centre-lock hubs, a 6-bolt to centre-lock adapter is available separately.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003eAdapters: \u003c\/strong\u003e160mm rotors typically install without adapters on standard post mount caliper setups. 180mm rotors require a post mount adapter to raise the caliper to the correct height. Adapter required and sold separately — ask us at the workshop and we will confirm the correct adapter for your specific frame and fork.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cstrong\u003eBolts: \u003c\/strong\u003erotor bolts are included. Standard M5 T25 Torx rotor bolts.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\"\u003e\u003cem\u003eAvailable in 160mm and 180mm. Sold individually.\u003c\/em\u003e\u003c\/p\u003e","brand":"Shimano","offers":[{"title":"160mm","offer_id":45480183726127,"sku":null,"price":39.95,"currency_code":"CAD","in_stock":true},{"title":"180mm","offer_id":45480183758895,"sku":null,"price":49.95,"currency_code":"CAD","in_stock":true},{"title":"203mm","offer_id":45480183791663,"sku":null,"price":59.95,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0751\/8784\/7215\/files\/SM-RT66Shimnaorotor.jpg?v=1781541857","url":"https:\/\/evercoastbicycles.ca\/products\/shimano-sm-rt66-6-bolt-disc-brake-rotor","provider":"Evercoast Bicycle Co.","version":"1.0","type":"link"}