{"product_id":"otk-genuine-50mm-kz-rear-axle","title":"OTK Genuine 50mm KZ Rear Axle","description":"\u003cp\u003eThe \u003cstrong\u003eOTK Genuine 50mm KZ rear axle\u003c\/strong\u003e is a genuine 1030mm replacement and setup axle for compatible OTK-based gearbox kart chassis. Available in multiple hardness options, it is ideal for KZ race preparation, chassis setup and replacing worn or damaged axles.\u003c\/p\u003e\n\n\u003cp\u003eSourced directly from OTK, this is a genuine manufacturer component designed for KZ and gearbox kart applications on compatible OTK-based chassis. Whether you are replacing a worn or damaged axle ahead of a race weekend, fine-tuning rear-end grip and handling balance, or preparing a spare chassis for testing, this axle is a reliable, competition-ready choice for KZ racers, mechanics and teams running compatible OTK-based machinery.\u003c\/p\u003e\n\n\u003cp\u003eRear axle selection is one of the most important chassis setup decisions on a KZ kart. The stiffness of the axle directly affects how the rear of the kart behaves through corners, under braking and on corner exit. KZ and gearbox karts place significant load through the rear axle due to gear changes, braking force and engine torque, making axle choice particularly important for both performance and consistency. A harder axle tends to reduce rear flex, which can improve stability and suit higher-grip circuits, heavier drivers or conditions where the kart is already generating strong rear traction. Softer options allow more chassis movement, which can help the kart work in lower-grip conditions or on circuits where rear-end rotation is needed.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eKey features:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eGenuine OTK KZ rear axle — not an aftermarket or pattern part\u003c\/li\u003e\n\u003cli\u003e50mm diameter, designed for OTK-based KZ chassis using a 50mm rear axle specification\u003c\/li\u003e\n\u003cli\u003eLength: 1030mm\u003c\/li\u003e\n\u003cli\u003eOTK item number: 0054.H0\u003c\/li\u003e\n\u003cli\u003eAvailable in multiple hardness options depending on variant\u003c\/li\u003e\n\u003cli\u003eDesigned for KZ 125cc gearbox kart applications\u003c\/li\u003e\n\u003cli\u003eSuitable for compatible OTK-based KZ chassis including Tony Kart, Kosmic, Exprit and LN Kart\u003c\/li\u003e\n\u003cli\u003eSold individually\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eVariant guide:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eType U — Extra Soft:\u003c\/strong\u003e For very low-grip conditions or circuits requiring maximum rear-end rotation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType Q — Soft:\u003c\/strong\u003e For lower-grip conditions where additional chassis movement is beneficial\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType N — Medium:\u003c\/strong\u003e Standard factory baseline, suitable for a wide range of conditions\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType H — Hard:\u003c\/strong\u003e For higher-grip circuits or conditions where rear stability is the priority\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType HH — Extra Hard:\u003c\/strong\u003e For high-grip circuits, heavier drivers or where maximum rear stiffness is required\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType HD — Extra Extra Hard:\u003c\/strong\u003e For the highest-grip conditions or specific setup requirements\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eSetup note:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAxle hardness has a direct effect on KZ kart handling. A harder axle generally reduces rear flex and suits high-grip conditions, heavier drivers or circuits where stability and drive off corners is the priority. A softer axle allows more chassis movement and can help the kart generate rear grip and rotation in lower-traction conditions. On KZ karts, axle choice also influences braking stability and behaviour under gear changes. Always select your axle based on circuit conditions, class requirements, driver weight and setup advice from your team or mechanic.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eProduct details:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eBrand: OTK (genuine part)\u003c\/li\u003e\n\u003cli\u003eOTK item number: 0054.H0\u003c\/li\u003e\n\u003cli\u003eDiameter: 50mm\u003c\/li\u003e\n\u003cli\u003eLength: 1030mm\u003c\/li\u003e\n\u003cli\u003eApplication: KZ \/ gearbox \/ shifter kart\u003c\/li\u003e\n\u003cli\u003eHardness options: Extra Soft (U) \/ Soft (Q) \/ Medium (N) \/ Hard (H) \/ Extra Hard (HH) \/ Extra Extra Hard (HD)\u003c\/li\u003e\n\u003cli\u003eSold individually\u003c\/li\u003e\n\u003cli\u003eAxle keys, bearings, hubs, sprocket carriers and other fittings are not included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eCompatibility note:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThis axle is designed for compatible OTK-based KZ gearbox kart chassis using a 50mm x 1030mm rear axle. It is commonly used on the following chassis:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eTony Kart\u003c\/li\u003e\n\u003cli\u003eKosmic\u003c\/li\u003e\n\u003cli\u003eExprit\u003c\/li\u003e\n\u003cli\u003eLN Kart\u003c\/li\u003e\n\u003cli\u003eEOS\u003c\/li\u003e\n\u003cli\u003eRed Speed\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eBefore ordering, please confirm your chassis model, axle diameter, axle length, brake hub, sprocket carrier, wheel hub and bearing carrier compatibility. This axle is not a universal fit and is intended only for compatible OTK-based KZ chassis using the 50mm x 1030mm rear axle specification.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eIdeal for:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eReplacing a worn or damaged KZ rear axle on an OTK-based chassis\u003c\/li\u003e\n\u003cli\u003eKZ chassis setup and rear-end grip adjustment\u003c\/li\u003e\n\u003cli\u003eRace preparation and testing on gearbox kart applications\u003c\/li\u003e\n\u003cli\u003eKZ mechanics and race teams managing multiple chassis\u003c\/li\u003e\n\u003cli\u003eOwner-drivers maintaining or setting up their own KZ kart\u003c\/li\u003e\n\u003cli\u003eCompetitive KZ karting across a range of circuits and conditions\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eA genuine OTK component, built to the correct specification for competitive KZ karting on compatible OTK-based gearbox kart chassis.\u003c\/p\u003e","brand":"OTK","offers":[{"title":"Extra Soft (U)","offer_id":58435810656581,"sku":"0054H0U","price":136.84,"currency_code":"GBP","in_stock":true},{"title":"Soft (Q)","offer_id":58436034232645,"sku":"0054H0Q","price":136.84,"currency_code":"GBP","in_stock":true},{"title":"Medium (N)","offer_id":58436034265413,"sku":"0054H0N","price":136.84,"currency_code":"GBP","in_stock":true},{"title":"Hard (H)","offer_id":58436034298181,"sku":"0054H0H","price":136.84,"currency_code":"GBP","in_stock":true},{"title":"Extra Hard (HH)","offer_id":58436034330949,"sku":"0054H0HH","price":136.84,"currency_code":"GBP","in_stock":true},{"title":"Extra Extra Hard (HD)","offer_id":58436034363717,"sku":"0054H0HD","price":136.84,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0946\/2785\/6709\/files\/otk-genuine-50mm-kz-rear-axle-1030mm_d432ee24-4cc2-4fa5-8977-2bacefed84b1.png?v=1782992456","url":"https:\/\/thekartstore.com\/products\/otk-genuine-50mm-kz-rear-axle","provider":"IC Kartstore","version":"1.0","type":"link"}