{"product_id":"50mm-ultra-soft-axle","title":"50mm Ultra Soft Axle for OTK Chassis","description":"\u003cp\u003eA kart axle is the solid bar that spins your rear wheels and carries the sprocket driven by the chain. This 50mm ultra soft version from SMKart flexes just the right amount under cornering loads so the tires stay planted longer, giving beginners more confidence and experts another tuning tool for quicker lap times.\u003c\/p\u003e\u003cp\u003eMade from high-grade steel in a silver finish, the axle is a direct replacement for OTK chassis. It transfers engine power smoothly while its ultra soft stiffness lets the rear end work with the track instead of fighting it. Four-cycle or inboard brake setups use three AK003 and one AK004 inboard fasteners plus four AK003 outboard; keys are sold separately.\u003c\/p\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDiameter\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e50mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eStiffness\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUltra Soft\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eInboard Fasteners\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e3x AK003 + 1x AK004\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOutboard Fasteners\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4x AK003\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eKeys\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eSold separately\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003cp\u003eRacers pick this axle when they want controlled flex to improve grip on technical corners without sacrificing straight-line stability. Whether you are dialing in your first OTK rental kart or chasing tenths in a national series, the SMKart 50mm ultra soft axle delivers predictable handling you can trust.\u003c\/p\u003e\u003cdiv class=\"faq-q\"\u003e\u003cstrong\u003eWill this 50mm ultra soft axle fit my OTK kart chassis?\u003c\/strong\u003e\u003c\/div\u003e\u003cdiv class=\"faq-a\"\u003eYes, it is a direct replacement designed specifically for OTK chassis. Confirm your current axle diameter is 50mm before ordering.\u003c\/div\u003e\u003cdiv class=\"faq-q\"\u003e\u003cstrong\u003eWhat fasteners and keys do I need to install this ultra soft kart axle?\u003c\/strong\u003e\u003c\/div\u003e\u003cdiv class=\"faq-a\"\u003eInboard brake or four-cycle setups require 3x AK003 plus 1x AK004; outboard brake applications use 4x AK003. All keys are sold separately.\u003c\/div\u003e\u003cdiv class=\"faq-q\"\u003e\u003cstrong\u003eDoes this axle come with a warranty?\u003c\/strong\u003e\u003c\/div\u003e\u003cdiv class=\"faq-a\"\u003eYes, it carries the standard SMKart warranty against manufacturing defects. Proper installation and regular inspection for wear are required to maintain coverage.\u003c\/div\u003e\n\n\u003cdiv style=\"margin:28px 0;font-family:inherit;\"\u003e\n  \u003cdetails style=\"border:1px solid #d0e4f0;border-radius:8px;overflow:hidden;\"\u003e\n    \u003csummary style=\"cursor:pointer;padding:12px 18px;background:#eef6fc;font-weight:700;font-size:1.02em;list-style:none;display:flex;align-items:center;gap:10px;\"\u003e\n      \u003cspan style=\"font-size:1.1em;color:#1a6090;\"\u003e▸\u003c\/span\u003e\n      \u003cspan style=\"color:#1a6090;\"\u003eProduct Highlights\u003c\/span\u003e\n    \u003c\/summary\u003e\n    \u003cul style=\"margin:0;padding:10px 18px 14px 18px;list-style:none;background:#fff;\"\u003e\n\u003cli style=\"padding:7px 0;border-bottom:1px solid #eef2f6;display:flex;gap:10px;align-items:flex-start;\"\u003e\n\u003cspan style=\"color:#2a8a4a;font-weight:bold;flex-shrink:0;\"\u003e✓\u003c\/span\u003e\u003cspan\u003eSolid steel bar connects the rear wheels and carries the drive sprocket.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"padding:7px 0;border-bottom:1px solid #eef2f6;display:flex;gap:10px;align-items:flex-start;\"\u003e\n\u003cspan style=\"color:#2a8a4a;font-weight:bold;flex-shrink:0;\"\u003e✓\u003c\/span\u003e\u003cspan\u003e50 mm diameter axle is designed specifically for OTK chassis.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"padding:7px 0;border-bottom:1px solid #eef2f6;display:flex;gap:10px;align-items:flex-start;\"\u003e\n\u003cspan style=\"color:#2a8a4a;font-weight:bold;flex-shrink:0;\"\u003e✓\u003c\/span\u003e\u003cspan\u003eUltra soft stiffness rating allows controlled flex for improved corner grip.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"padding:7px 0;border-bottom:1px solid #eef2f6;display:flex;gap:10px;align-items:flex-start;\"\u003e\n\u003cspan style=\"color:#2a8a4a;font-weight:bold;flex-shrink:0;\"\u003e✓\u003c\/span\u003e\u003cspan\u003eSilver steel finish with machined keyways for sprocket and brake rotor location.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"padding:7px 0;border-bottom:1px solid #eef2f6;display:flex;gap:10px;align-items:flex-start;\"\u003e\n\u003cspan style=\"color:#2a8a4a;font-weight:bold;flex-shrink:0;\"\u003e✓\u003c\/span\u003e\u003cspan\u003eInboard brake or four-cycle setups require three AK003 and one AK004 fasteners.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"padding:7px 0;border-bottom:1px solid #eef2f6;display:flex;gap:10px;align-items:flex-start;\"\u003e\n\u003cspan style=\"color:#2a8a4a;font-weight:bold;flex-shrink:0;\"\u003e✓\u003c\/span\u003e\u003cspan\u003eOutboard brake setups use four AK003 fasteners.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"padding:7px 0;border-bottom:1px solid #eef2f6;display:flex;gap:10px;align-items:flex-start;\"\u003e\n\u003cspan style=\"color:#2a8a4a;font-weight:bold;flex-shrink:0;\"\u003e✓\u003c\/span\u003e\u003cspan\u003eKeys for sprocket and brake mounting are sold separately.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"padding:7px 0;border-bottom:1px solid #eef2f6;display:flex;gap:10px;align-items:flex-start;\"\u003e\n\u003cspan style=\"color:#2a8a4a;font-weight:bold;flex-shrink:0;\"\u003e✓\u003c\/span\u003e\u003cspan\u003eDirect replacement axle for standard OTK kart chassis.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"padding:7px 0;border-bottom:1px solid #eef2f6;display:flex;gap:10px;align-items:flex-start;\"\u003e\n\u003cspan style=\"color:#2a8a4a;font-weight:bold;flex-shrink:0;\"\u003e✓\u003c\/span\u003e\u003cspan\u003eTransfers engine power to the rear wheels while tuning rear grip.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/details\u003e\n\u003c\/div\u003e","brand":"SMKart","offers":[{"title":"Default Title","offer_id":53415121158462,"sku":"AXT050E","price":204.03,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0962\/4721\/8494\/files\/smkart-50mm-ultra-soft-axle-angle.jpg?v=1777628727","url":"https:\/\/swiftkarting.com\/products\/50mm-ultra-soft-axle","provider":"Swift Karting","version":"1.0","type":"link"}