{"product_id":"lewmar-50mm-synchro-block-single-990-lb-working-load-limit-traveler-compatible-29925001bk","title":"Lewmar 50mm Synchro Block Single, 990 lb Working Load Limit, Traveler Compatible - 29925001BK","description":"\u003cp\u003eThe Lewmar Synchro Block Single (29925001BK) is a 50mm single sheave block engineered for sailboat running rigging where efficiency and durability matter. It carries a 990 lb working load limit and accommodates lines from 1\/4 inch to 3\/8 inch in diameter, making it suited to halyard tuning, mainsheet systems, mast foot and head blocks, and boom vangs.\u003c\/p\u003e\u003cp\u003eThe block uses a high-density Free-Spin bearing that reduces axle diameter, cutting friction and delivering up to 40% more efficiency compared to budget blocks. A self-aligning head and optimized block geometry keep the line tracking smoothly under load, while the larger sheave diameter further minimizes rope friction for smoother power transfer and reduced rope wear. The cheeks are stiff, glass fiber reinforced material that resists line wedging, and the block includes a stainless steel strap for added strength and long service life.\u003c\/p\u003e\u003cp\u003eDesign is versatile: the block switches easily between swiveling and fixed shackle configurations, and its precision-engineered shackle post gives seamless compatibility with Lewmar traveler systems. This makes the Synchro Block Single 29925001BK a practical upgrade for sailors looking to improve sail handling response without switching to a full multi-block system.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Lewmar\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 29925001BK\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSheave Diameter:\u003c\/strong\u003e 50 millimeters\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWorking Load Limit:\u003c\/strong\u003e 990 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLine Diameter Accommodated:\u003c\/strong\u003e 1\/4 inch to 3\/8 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBearing Type:\u003c\/strong\u003e Free-Spin bearing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheek Material:\u003c\/strong\u003e Glass fiber reinforced\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStrap Material:\u003c\/strong\u003e Stainless steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShackle Configuration:\u003c\/strong\u003e Switchable between swiveling and fixed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTraveler Compatibility:\u003c\/strong\u003e Compatible with Lewmar traveler systems\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.9 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Sailboat Blocks\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the working load limit of the Lewmar Synchro Block Single 29925001BK?\u003c\/strong\u003e The Lewmar Synchro Block Single 29925001BK has a working load limit of 990 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat line sizes fit this block?\u003c\/strong\u003e The 29925001BK accommodates line diameters from 1\/4 inch to 3\/8 inch.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat sheave size does this block use?\u003c\/strong\u003e It uses a 50 millimeter sheave, which pairs with its Free-Spin bearing to reduce friction during operation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the shackle be changed from swiveling to fixed?\u003c\/strong\u003e Yes, the Lewmar Synchro Block Single is designed to switch easily between swiveling and fixed shackle configurations.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this block compatible with Lewmar traveler systems?\u003c\/strong\u003e Yes, the 29925001BK has a precision-engineered shackle post for seamless compatibility with Lewmar traveler systems.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the block's construction material?\u003c\/strong\u003e The cheeks are stiff, glass fiber reinforced material that resists lines wedging, and the block includes a stainless steel strap for added strength.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Lewmar 29925001BK weigh?\u003c\/strong\u003e This block weighs 0.9 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat sailing applications is this block used for?\u003c\/strong\u003e The Synchro Block Single is suited to halyard tuning, mainsheet systems, mast foot and head blocks, and boom vangs.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy does this block reduce friction compared to standard blocks?\u003c\/strong\u003e The high-density Free-Spin bearing reduces axle diameter and, combined with optimized block geometry and a self-aligning head, delivers up to 40% more efficiency than budget blocks.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the sheave diameter affect performance?\u003c\/strong\u003e Yes, the 50 millimeter sheave on the 29925001BK is sized larger to minimize rope friction and support smoother power transfer with reduced rope wear.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Lewmar Synchro Block Single a single or double sheave block?\u003c\/strong\u003e The 29925001BK is a single sheave block, as indicated by its Synchro Block Single designation.\u003c\/p\u003e","brand":"Lewmar","offers":[{"title":"Default Title","offer_id":49025132331227,"sku":"LEW-29925001BK","price":27.8,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/LEW-29925001BK__27926.1722352939.500.750.jpg?v=1785329116","url":"https:\/\/www.goodvibesmarina.com\/products\/lewmar-50mm-synchro-block-single-990-lb-working-load-limit-traveler-compatible-29925001bk","provider":"Good Vibes Marina","version":"1.0","type":"link"}