OTK Kart Axles: Rear Axles for All 8 OTK Chassis Brands
Genuine OTK rear axles fitting all 8 OTK Kart Group brands, including Tony Kart, Kosmic, Exprit, Redspeed, EOS, Gillard, CS55 and LN Kart. Available in 25mm, 30mm, 40mm, and 50mm diameters across hardness grades E through HD, in stock and ready to ship from the Netherlands.
The rear axle transfers engine power to the wheels while holding chassis geometry steady through every corner. Get the hardness wrong and you'll feel it in how the kart flexes and handles, not just in fit. Tony Kart, Kosmic Kart, Exprit Kart, Redspeed Kart, EOS Kart, and Gillard Kart share the same chassis platform under OTK Kart Group, along with the Carlos Sainz CS55 and LN (Lando Norris) signature karts. That means one axle range covers all eight brands. Only the paint changes, not the parts.
OTK axles are made from high-grade steel and available in 25mm, 30mm, 40mm, and 50mm diameters, across ten hardness grades: E, U, P, Q, N, O, H, A, HH, and HD. Softer axles flex more, giving extra side bite and grip in fast corners. Harder axles give less grip in fast corners but offer more traction and stability under braking. Choosing the right hardness is a setup decision as much as a fit one. Chassis manufacturers and drivers commonly adjust it by track condition and class, not just by chassis model..
How to choose the right OTK axle
Start with diameter. This is the non-negotiable fit factor and must match your hub and bearing carrier specification exactly. From there, hardness is a tuning choice. Check our Go Kart Axle Hardness Chart for guidance by track grip level and class, or contact us with your chassis brand, class, and typical track conditions and we'll recommend a starting point.
For a complete rear end setup, pair axles with Hubs, Cassettes & Bearings, and Wheels.