{"product_id":"sidi-hyper-extension-system","title":"SIDI Hyper Extension System","description":"\u003cdiv class=\"trd trd--sidi\"\u003e\n\u003csection class=\"trd-hero\"\u003e\u003cp class=\"trd-eyebrow\"\u003eSIDI · Boot Parts\u003c\/p\u003e\n\u003ch2 class=\"trd-headline\"\u003eReplaceable ankle extension limiter for Crossair boots\u003c\/h2\u003e\n\u003cp class=\"trd-lead\"\u003eThe SIDI Hyper Extension System is a replacement block system built for SIDI boots that use this mechanism. Designed to help limit ankle and foot hyperextension, it supports the boot’s structure and intended protective performance while keeping natural mobility in mind.\u003c\/p\u003e\n\u003cp class=\"trd-lead\"\u003eMade to swap in for worn or damaged components, this part helps control rearward movement without unnecessarily restricting flexibility. It’s offered in Black, Red, and White, with size ranges from 37-39 through 48-50, and it fits the Crossair, Crossair HD Enduro, and Crossair X boots as listed by SIDI.\u003c\/p\u003e\n\u003cul class=\"trd-chips\"\u003e\n\u003cli class=\"trd-chip\"\u003e\n\u003cspan class=\"trd-chip-label\"\u003eCategory\u003c\/span\u003e\u003cspan class=\"trd-chip-value\"\u003eBoot Parts\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"trd-chip\"\u003e\n\u003cspan class=\"trd-chip-label\"\u003eFits\u003c\/span\u003e\u003cspan class=\"trd-chip-value\"\u003eSIDI Crossair, Crossair HD Enduro, Crossair X\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\u003c\/section\u003e\u003cdiv class=\"trd-cards trd-cards--3\"\u003e\n\u003carticle class=\"trd-card\"\u003e\u003cdiv class=\"trd-card-body\"\u003e\n\u003ch3 class=\"trd-card-title\"\u003eHyperextension control\u003c\/h3\u003e\n\u003cp class=\"trd-card-text\"\u003eThis hyper extension block system is designed to help limit ankle and foot overextension. By managing rearward movement at the ankle\/foot area, it adds a functional layer to the boot’s support system while still aiming to preserve natural mobility during use.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/article\u003e\u003carticle class=\"trd-card\"\u003e\u003cdiv class=\"trd-card-body\"\u003e\n\u003ch3 class=\"trd-card-title\"\u003eMaintains boot performance\u003c\/h3\u003e\n\u003cp class=\"trd-card-text\"\u003eReplacing worn components can help keep the boot functioning as intended. The Hyper Extension System is built to support the boot’s structure and protective performance, helping restore the purpose of the original system when the existing block is damaged or worn out.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/article\u003e\u003carticle class=\"trd-card\"\u003e\u003cdiv class=\"trd-card-body\"\u003e\n\u003ch3 class=\"trd-card-title\"\u003eFitment and installation\u003c\/h3\u003e\n\u003cp class=\"trd-card-text\"\u003eThis replacement part is listed by SIDI as fitting the Crossair, Crossair HD Enduro, and Crossair X boots. Hardware is included for straightforward installation, making it easier to refresh the system without sourcing additional mounting pieces separately.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/article\u003e\n\u003c\/div\u003e\n\u003csection class=\"trd-section trd-section--specs\"\u003e\u003ch2 class=\"trd-section-title\"\u003eSpecifications\u003c\/h2\u003e\n\u003cdiv class=\"trd-table-wrap\"\u003e\u003ctable class=\"trd-table trd-table--specs\"\u003e\u003ctbody\u003e\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSIDI Reference\u003c\/th\u003e\n\u003ctd\u003e345\u003c\/td\u003e\n\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"trd-section trd-section--compatibility\"\u003e\u003ch2 class=\"trd-section-title\"\u003eFits These SIDI Boots\u003c\/h2\u003e\n\u003cdiv class=\"trd-table-wrap\"\u003e\u003ctable class=\"trd-table\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\u003ctd\u003eSIDI Crossair\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eSIDI Crossair HD Enduro\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eSIDI Crossair X\u003c\/td\u003e\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\n\u003cp class=\"trd-notice\"\u003eFitment as listed by SIDI for this part.\u003c\/p\u003e\u003c\/section\u003e\u003csection class=\"trd-section trd-section--features\"\u003e\u003ch2 class=\"trd-section-title\"\u003eFeatures \u0026amp; Specifications\u003c\/h2\u003e\n\u003cdiv class=\"trd-table-wrap\"\u003e\u003ctable class=\"trd-table\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\u003ctd\u003eHelps limit ankle and foot hyperextension.\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eSupports boot structure and protective performance.\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eMaintains flexibility while enhancing stability.\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eReplacement component for worn or damaged parts.\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eIncludes hardware for easy installation.\u003c\/td\u003e\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\n\u003cp class=\"trd-notice\"\u003eAs listed by SIDI for this boot part.\u003c\/p\u003e\u003c\/section\u003e\u003csection class=\"trd-section trd-section--options\"\u003e\u003ch2 class=\"trd-section-title\"\u003eAvailable Colors \u0026amp; Sizes\u003c\/h2\u003e\n\u003cdiv class=\"trd-table-wrap\"\u003e\u003ctable class=\"trd-table\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth scope=\"col\"\u003eColor\u003c\/th\u003e\n\u003cth scope=\"col\"\u003eSizes\u003c\/th\u003e\n\u003cth scope=\"col\"\u003eSIDI Part Numbers\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlack\u003c\/td\u003e\n\u003ctd\u003e37-39, 40-41, 42-43, 44-45, 46-47, 48-50\u003c\/td\u003e\n\u003ctd\u003e2428-0005-39, 2428-0005-41, 2428-0005-43, 2428-0005-45, 2428-0005-47, 2428-0005-50\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRed\u003c\/td\u003e\n\u003ctd\u003e37-39, 40-41, 42-43, 44-45, 46-47, 48-50\u003c\/td\u003e\n\u003ctd\u003e2428-0001-39, 2428-0001-41, 2428-0001-43, 2428-0001-45, 2428-0001-47, 2428-0001-50\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWhite\u003c\/td\u003e\n\u003ctd\u003e37-39, 40-41, 42-43, 44-45, 46-47, 48-50\u003c\/td\u003e\n\u003ctd\u003e2428-0009-39, 2428-0009-41, 2428-0009-43, 2428-0009-45, 2428-0009-47, 2428-0009-50\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\u003c\/section\u003e\n\u003c\/div\u003e","brand":"Sidi","offers":[{"title":"Black \/ 37-39","offer_id":68179405570199,"sku":"2428-0005-39","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 40-41","offer_id":68179405766807,"sku":"2428-0005-41","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 42-43","offer_id":68179405799575,"sku":"2428-0005-43","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 44-45","offer_id":68179405832343,"sku":"2428-0005-45","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 46-47","offer_id":68179405865111,"sku":"2428-0005-47","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 48-50","offer_id":68179405897879,"sku":"2428-0005-50","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Red \/ 37-39","offer_id":68179405930647,"sku":"2428-0001-39","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Red \/ 40-41","offer_id":68179405963415,"sku":"2428-0001-41","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Red \/ 42-43","offer_id":68179405996183,"sku":"2428-0001-43","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Red \/ 44-45","offer_id":68179406028951,"sku":"2428-0001-45","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Red \/ 46-47","offer_id":68179406061719,"sku":"2428-0001-47","price":8.99,"currency_code":"USD","in_stock":true},{"title":"Red \/ 48-50","offer_id":68179406094487,"sku":"2428-0001-50","price":8.99,"currency_code":"USD","in_stock":true},{"title":"White \/ 37-39","offer_id":68179406127255,"sku":"2428-0009-39","price":8.99,"currency_code":"USD","in_stock":true},{"title":"White \/ 40-41","offer_id":68179406160023,"sku":"2428-0009-41","price":8.99,"currency_code":"USD","in_stock":true},{"title":"White \/ 42-43","offer_id":68179406192791,"sku":"2428-0009-43","price":8.99,"currency_code":"USD","in_stock":true},{"title":"White \/ 44-45","offer_id":68179406225559,"sku":"2428-0009-45","price":8.99,"currency_code":"USD","in_stock":true},{"title":"White \/ 46-47","offer_id":68179406258327,"sku":"2428-0009-47","price":8.99,"currency_code":"USD","in_stock":true},{"title":"White \/ 48-50","offer_id":68179406291095,"sku":"2428-0009-50","price":8.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0585\/4884\/6743\/files\/2428-0001-391697759129-3283838.jpg?v=1793214302","url":"https:\/\/allamericanktm.com\/products\/sidi-hyper-extension-system","provider":"All American KTM","version":"1.0","type":"link"}