{"product_id":"pulegge-contesub-black-zirconia","title":"Black Zirconia Pulleys","description":"\u003ch2\u003eBlack Zirconia Pulleys for Roller Spearguns\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003epair of Black Zirconia pulleys\u003c\/strong\u003e for Roller Speargun spearguns is built to ensure high reliability for spearfishing and freediving. The outer structure in \u003cstrong\u003eblack Delrin\u003c\/strong\u003e is machined from solid stock, ensuring dimensional precision and the strength required for underwater use.\u003c\/p\u003e\n\n\u003ch3\u003eTechnical features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e high-strength black Delrin, unaffected by corrosion and marine temperatures\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaximum working load:\u003c\/strong\u003e 169 kg, significantly higher than equivalent 316 stainless steel bearings\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRotation speed limit:\u003c\/strong\u003e 9000 rpm, more than three times higher than traditional stainless steel bearings\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOutside diameter:\u003c\/strong\u003e 28 mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGroove diameter (trapezoidal section):\u003c\/strong\u003e 20 mm, compatible with bands up to 16 mm in diameter\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInner shaft bore diameter:\u003c\/strong\u003e 6 mm, intentionally larger to transfer the load to the bearing\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThickness:\u003c\/strong\u003e 15 mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eConstruction details and functional advantages\u003c\/h3\u003e\n\u003cp\u003eThe pulley is equipped with a calibrated cap that allows the bearing to be precisely centered on the centerline, optimizing \u003cstrong\u003esmooth rotation\u003c\/strong\u003e and reducing premature wear. The central bore, enlarged relative to the axle, shifts the working load primarily onto the bearing, improving \u003cstrong\u003emechanical efficiency\u003c\/strong\u003e and protecting the pulley from excessive stress.\u003c\/p\u003e\n\n\u003cp\u003eThe trapezoidal groove is designed to accommodate spearfishing bands up to 16 mm in diameter, ensuring \u003cstrong\u003eproper grip\u003c\/strong\u003e without compromising the smoothness and responsiveness of the pulley during tracking and shaft release.\u003c\/p\u003e\n\n\u003cp\u003eIn addition, Black Zirconia pulleys require minimal maintenance, as they are highly resistant to the corrosive agents typical of the marine environment and to temperature variations, ensuring long-lasting use over time.\u003c\/p\u003e","brand":"Contesub","offers":[{"title":"Default Title","offer_id":56926622875993,"sku":"AR003","price":64.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0993\/6732\/1945\/files\/Pulegge_Black_Zirconia.png?v=1782068732","url":"https:\/\/deepbluesub.com\/en\/products\/contesub-black-zirconia-pulleys","provider":"DEEP BLUE - Freediving \u0026 Spearfishing","version":"1.0","type":"link"}