{"title":"Mainsheet Jammers","description":"\u003cp\u003e\u003cspan data-sheets-root=\"1\"\u003eAllen Mainsheet Jammers are designed for smooth, reliable performance with extensive research and development behind their design. Featuring a cold-forged bearing system with a ball locating groove, they ensure smooth rotation while preventing lateral movement. The cam cleat angle and height are optimised for easy jamming and quick release, with rotation options of 180°, 220°, or 360°.\u003c\/span\u003e\u003c\/p\u003e","products":[{"product_id":"standard-height-mainsheet-jammer","title":"Mainsheet Jammer","description":"\u003cdiv\u003e\n\u003ch3\u003eStandard Height Mainsheet Jammer\u003c\/h3\u003e\n\u003cp\u003eDesigned for dinghies and keelboats that require a central mainsheet jammer, this Standard Height Mainsheet Jammer provides smooth, reliable mainsheet control with an optimised cleating position for easy adjustment under load.\u003c\/p\u003e\n\u003cp\u003eFeaturing Allen's cold-forged bearing system with a ball-locating groove, the arm rotates smoothly while preventing lateral movement. The rotation can be adjusted to 180°, 220°, or 360° using the underside stopper pins, while the carefully optimised arm angle ensures effortless cleating and uncleating. Supplied with an aluminium ball bearing cam cleat and Mega Pro-Lead for smooth and reliable rope handling.\u003c\/p\u003e\n\u003ch4\u003eKey Features:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eStandard height mainsheet jammer\u003c\/li\u003e\n\u003cli\u003eIdeal for dinghies and keelboats\u003c\/li\u003e\n\u003cli\u003eCold-forged bearing system for smooth rotation\u003c\/li\u003e\n\u003cli\u003eBall-locating groove reduces lateral arm movement\u003c\/li\u003e\n\u003cli\u003eAdjustable rotation settings of 180°, 220°, or 360°\u003c\/li\u003e\n\u003cli\u003eOptimised arm angle for easy cleating and uncleating\u003c\/li\u003e\n\u003cli\u003eFitted with an aluminium ball bearing cam cleat and Mega Pro-Lead\u003c\/li\u003e\n\u003cli\u003eAvailable with or without a 60mm Pro-Ratchet Block\u003c\/li\u003e\n\u003cli\u003eDurable, corrosion-resistant construction\u003c\/li\u003e\n\u003cli\u003eIdeal for racing and performance sailing applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Allen","offers":[{"title":"None","offer_id":57196830294391,"sku":"A5166","price":170.03,"currency_code":"GBP","in_stock":true},{"title":"A2160","offer_id":57196830327159,"sku":"A5166ASSEMBLED","price":214.72,"currency_code":"GBP","in_stock":true},{"title":"A2160Fiddle","offer_id":57196830359927,"sku":"A5166FIDDLE","price":242.89,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0983\/7087\/9863\/files\/A5166ASS-resized.jpg?v=1785857715"},{"product_id":"compact-mainsheet-jammer","title":"Mainsheet Jammer - Compact","description":"\u003cdiv\u003e\n\u003ch3\u003eCompact Mainsheet Jammer\u003c\/h3\u003e\n\u003cp\u003eDesigned for dinghies and keelboats that require a central mainsheet jammer in a lower-profile, space-saving format, this Compact Mainsheet Jammer delivers smooth operation and reliable control without taking up unnecessary cockpit space.\u003c\/p\u003e\n\u003cp\u003eFeaturing Allen's cold-forged bearing system with a ball-locating groove, the arm rotates smoothly while preventing lateral movement for improved durability and feel. The arm can be set to rotate through 180°, 220°, or 360° using adjustable stopper pins, while the optimised cleat angle ensures easy cleating and releasing.\u003c\/p\u003e\n\u003ch4\u003eKey Features:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eCompact, low-profile mainsheet jammer design\u003c\/li\u003e\n\u003cli\u003eIdeal for dinghies and keelboats\u003c\/li\u003e\n\u003cli\u003eCold-forged bearing system for smooth rotation\u003c\/li\u003e\n\u003cli\u003eBall-locating groove reduces lateral arm movement\u003c\/li\u003e\n\u003cli\u003eAdjustable rotation settings of 180°, 220°, or 360°\u003c\/li\u003e\n\u003cli\u003eOptimised arm angle for easy cleating and uncleating\u003c\/li\u003e\n\u003cli\u003eFitted with a medium aluminium ball bearing cam cleat with Mega Pro-Lead\u003c\/li\u003e\n\u003cli\u003eAvailable with or without a 60mm Pro-Ratchet Block\u003c\/li\u003e\n\u003cli\u003eDurable, corrosion-resistant construction\u003c\/li\u003e\n\u003cli\u003eIdeal for racing and performance sailing applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Allen","offers":[{"title":"None","offer_id":57196830458231,"sku":"A5166COMP","price":166.79,"currency_code":"GBP","in_stock":true},{"title":"A2160 Ratchet","offer_id":57196830490999,"sku":"A5166COMP-ASS","price":212.24,"currency_code":"GBP","in_stock":true},{"title":"A2160WAVE Ratchet","offer_id":57196830523767,"sku":"A5166COMP-ASS-WAVE","price":212.24,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0983\/7087\/9863\/files\/A516620COMP-ASS.jpg?v=1781801137"},{"product_id":"dual-arm-standard-height-mainsheet-jammer","title":"Dual Arm Mainsheet Jammer","description":"\u003cdiv\u003e\n\u003ch3\u003eDual Arm Standard Height Mainsheet Jammer\u003c\/h3\u003e\n\u003cp\u003eDesigned for dinghies and keelboats that require centralised control of both the mainsheet and an additional control line, this Dual Arm Standard Height Mainsheet Jammer keeps essential controls within easy reach of the mainsheet trimmer. The dual arm configuration allows efficient adjustment of both lines from a central position, improving handling and cockpit organisation.\u003c\/p\u003e\n\u003cp\u003eBuilt around Allen's cold-forged bearing system, the jammer delivers smooth rotation while preventing lateral arm movement. The main arm is fitted with a medium aluminium ball bearing cam cleat with Mega Pro-Lead, while the lower arm features a small aluminium ball bearing cam cleat with Mega Pro-Lead and integrated sheaves for clean, efficient rope routing.\u003c\/p\u003e\n\u003ch4\u003eKey Features:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eStandard height dual arm mainsheet jammer\u003c\/li\u003e\n\u003cli\u003eDesigned for mainsheet and secondary control lines such as vangs\u003c\/li\u003e\n\u003cli\u003eCold-forged bearing system for smooth rotation\u003c\/li\u003e\n\u003cli\u003eBall-locating groove reduces lateral arm movement\u003c\/li\u003e\n\u003cli\u003eAdjustable rotation settings of 180°, 220°, or 360°\u003c\/li\u003e\n\u003cli\u003eOptimised arm angles for easy cleating and uncleating\u003c\/li\u003e\n\u003cli\u003eMedium aluminium ball bearing cam cleat with Mega Pro-Lead on the main arm\u003c\/li\u003e\n\u003cli\u003eSmall aluminium ball bearing cam cleat with Mega Pro-Lead on the lower arm\u003c\/li\u003e\n\u003cli\u003eTwin sheaves on the lower arm for efficient rope guidance\u003c\/li\u003e\n\u003cli\u003eAvailable with or without a 60mm Pro-Ratchet Block\u003c\/li\u003e\n\u003cli\u003eIdeal for racing and performance sailing applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Allen","offers":[{"title":"None","offer_id":57196830654839,"sku":"A5166DUAL","price":309.82,"currency_code":"GBP","in_stock":true},{"title":"A2160 Ratchet","offer_id":57196830687607,"sku":"A5166DUAL-ASS","price":400.46,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0983\/7087\/9863\/files\/A5166DUAL-ASS.jpg?v=1785857568"},{"product_id":"dual-arm-compact-height-mainsheet-jammer","title":"Dual Arm Mainsheet Jammer - Compact","description":"\u003cdiv\u003e\n\u003ch3\u003eCompact Dual Arm Mainsheet Jammer\u003c\/h3\u003e\n\u003cp\u003eDesigned for dinghies and keelboats that require centralised control of both the mainsheet and an additional control line, this Compact Dual Arm Mainsheet Jammer provides efficient, ergonomic line management in a low-profile package. The dual arm arrangement allows both controls to remain within easy reach of the mainsheet trimmer for faster and more efficient adjustments.\u003c\/p\u003e\n\u003cp\u003eBuilt around Allen's cold-forged bearing system, the jammer delivers smooth rotation while preventing lateral arm movement. The main arm is fitted with a medium aluminium ball bearing cam cleat with Mega Pro-Lead, while the lower arm features a small aluminium ball bearing cam cleat with Mega Pro-Lead and integrated sheaves to guide the control line cleanly into the cleat.\u003c\/p\u003e\n\u003ch4\u003eKey Features:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eCompact dual arm mainsheet jammer design\u003c\/li\u003e\n\u003cli\u003eIdeal for mainsheet and secondary control lines such as vangs\u003c\/li\u003e\n\u003cli\u003eCold-forged bearing system for smooth rotation\u003c\/li\u003e\n\u003cli\u003eBall-locating groove reduces lateral arm movement\u003c\/li\u003e\n\u003cli\u003eAdjustable rotation settings of 180°, 220°, or 360°\u003c\/li\u003e\n\u003cli\u003eOptimised arm angles for easy cleating and uncleating\u003c\/li\u003e\n\u003cli\u003eMedium aluminium ball bearing cam cleat with Mega Pro-Lead on the main arm\u003c\/li\u003e\n\u003cli\u003eSmall aluminium ball bearing cam cleat with Mega Pro-Lead on the lower arm\u003c\/li\u003e\n\u003cli\u003eIntegrated sheaves on the lower arm for efficient rope routing\u003c\/li\u003e\n\u003cli\u003eAvailable with or without a 60mm Pro-Ratchet Block\u003c\/li\u003e\n\u003cli\u003eIdeal for racing and performance sailing applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Allen","offers":[{"title":"None","offer_id":57196830916983,"sku":"A5166DUAL-COMP","price":309.82,"currency_code":"GBP","in_stock":true},{"title":"A2160 Ratchet","offer_id":57196830949751,"sku":"A5166DUAL-COMP-ASS","price":400.46,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0983\/7087\/9863\/files\/A5166DUAL-COMP-ASS-2.jpg?v=1781801139"},{"product_id":"self-aligning-mainsheet-jammer","title":"Self Aligning Mainsheet Jammer","description":"\u003cdiv\u003e\n\u003ch3\u003eStandard Height Self-Aligning Mainsheet Jammer\u003c\/h3\u003e\n\u003cp\u003eDesigned to improve mainsheet handling and boat control, this Standard Height Self-Aligning Mainsheet Jammer automatically turns through tacks and gybes without manual adjustment. The innovative offset block design keeps the cleat pointing away from the leeward side of the boat, preventing sheet wrap and allowing smoother, faster manoeuvres.\u003c\/p\u003e\n\u003cp\u003eFeaturing a cold-forged bearing system with a ball-locating groove for smooth rotation and minimal lateral movement, the jammer can be configured for 180°, 220°, or 360° rotation to suit different sailing setups. Supplied with an aluminium cam cleat and Mega Pro-Lead, it delivers reliable cleating and easy release when needed.\u003c\/p\u003e\n\u003ch4\u003eKey Features:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eSelf-aligning design for hands-free operation\u003c\/li\u003e\n\u003cli\u003ePrevents mainsheet wrapping during tacks and gybes\u003c\/li\u003e\n\u003cli\u003eImproves control and handling\u003c\/li\u003e\n\u003cli\u003eCold-forged bearing system for smooth rotation\u003c\/li\u003e\n\u003cli\u003eBall-locating groove reduces lateral arm movement\u003c\/li\u003e\n\u003cli\u003eAdjustable rotation settings of 180°, 220°, or 360°\u003c\/li\u003e\n\u003cli\u003eOptimised arm angle for easy cleating and uncleating\u003c\/li\u003e\n\u003cli\u003eSupplied with aluminium cam cleat and Mega Pro-Lead\u003c\/li\u003e\n\u003cli\u003eAvailable with or without a 60mm Pro-Ratchet Block\u003c\/li\u003e\n\u003cli\u003eIdeal for racing and performance sailing applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Allen","offers":[{"title":"None","offer_id":57196831605111,"sku":"A5266","price":183.27,"currency_code":"GBP","in_stock":true},{"title":"A2160 Ratchet","offer_id":57196831637879,"sku":"A5266ASS","price":227.94,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0983\/7087\/9863\/files\/A5266ASS-RESIZED.jpg?v=1785857764"},{"product_id":"compact-self-aligning-mainsheet-jammer","title":"Self Aligning Mainsheet Jammer - Compact","description":"\u003cdiv\u003e\n\u003ch3\u003eCompact Self-Aligning Mainsheet Jammer\u003c\/h3\u003e\n\u003cp\u003eDesigned to deliver smoother, faster manoeuvres, this Compact Self-Aligning Mainsheet Jammer automatically positions itself through tacks and gybes without manual adjustment. By offsetting and angling the ratchet block away from the cleat, the system generates a turning force that keeps the jammer pointing away from the leeward side of the boat, preventing sheet wrap and improving mainsheet control.\u003c\/p\u003e\n\u003cp\u003eBuilt around a cold-forged bearing system with a ball-locating groove for smooth rotation and reduced lateral movement, the jammer arm can be configured to rotate through 180°, 220°, or 360° to suit different setups. Supplied with an aluminium cam cleat and Mega Pro-Lead, it provides reliable cleating and easy release when needed.\u003c\/p\u003e\n\u003ch4\u003eKey Features:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003ePatented self-aligning design for hands-free operation\u003c\/li\u003e\n\u003cli\u003eReduces mainsheet wrapping during tacks and gybes\u003c\/li\u003e\n\u003cli\u003eImproves control and handling in fast manoeuvres\u003c\/li\u003e\n\u003cli\u003eCold-forged bearing system for smooth rotation\u003c\/li\u003e\n\u003cli\u003eBall-locating groove reduces lateral arm movement\u003c\/li\u003e\n\u003cli\u003eAdjustable rotation settings of 180°, 220°, or 360°\u003c\/li\u003e\n\u003cli\u003eOptimised arm angle for easy cleating and uncleating\u003c\/li\u003e\n\u003cli\u003eSupplied with aluminium cam cleat and Mega Pro-Lead\u003c\/li\u003e\n\u003cli\u003eAvailable with or without a 60mm Pro-Ratchet Block\u003c\/li\u003e\n\u003cli\u003eIdeal for racing and performance sailing applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Allen","offers":[{"title":"None","offer_id":57196831670647,"sku":"A5266COMP","price":180.01,"currency_code":"GBP","in_stock":true},{"title":"A2160 Ratchet","offer_id":57196831703415,"sku":"A5266COMP-ASS","price":225.46,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0983\/7087\/9863\/files\/A5266COMP-ASS-2-2.jpg?v=1781801152"}],"url":"https:\/\/allenbrothers.co.uk\/collections\/mainsheet-jammers.oembed","provider":"Allen | Performance Sailing Hardware","version":"1.0","type":"link"}