Athena presents the Big Bore Extreme Range

Alonte (Vicenza), 04th May 2026 – Athena is expanding its offering for the off-road segment with the Big Bore Extreme range, the complete line-up of cylinder kits developed for the leading 250cc 4-stroke motocross platforms.

With Big Bore Extreme, Athena brings to life a clear vision: turning a new idea of performance into reality for the major off-road applications. This range has been designed to deliver more substance, stronger drive and an even more engaging riding experience, without compromising the balance and rideability of the original platforms. From this vision comes a technical package capable of taking 250 4-stroke machines into the 300cc range, opening up a new dimension in off-road riding.

The kits are aimed at both amateur and professional riders looking for a fuller engine response, stronger drive out of corners, improved acceleration on restarts and the immediate traction needed in the most demanding riding conditions. At the same time, they also represent a concrete solution for riders preparing to step up from a 250cc to a 450cc, moving closer to a stronger power delivery and a more substantial riding feel.

At the core of the Big Bore Extreme range is a principle that has always been part of Athena's know-how: developing integrated systems in which every component is engineered to work in perfect synergy with the others. This is the soul of the project, but also one of the defining traits of Athena's approach, as the company has been developing big bore solutions for years starting from the OEM architectures and technical constraints of production bikes, with the goal of achieving a real step forward in performance while maintaining design consistency, reliability and ease of installation. In Big Bore Extreme, this philosophy takes shape in a package where the cylinder kit and engine management work together as a single system.

At the heart of the package is the 85 mm bore cylinder, engineered to withstand the typical demands of the most severe off-road use. Its architecture combines a steel liner co-cast into an aluminum body, a technical solution that helps ensure dimensional stability, wear resistance and consistent performance even under the harshest operating conditions. The increased bore makes it possible to bring displacement into the 300cc range, without requiring any machining to the crankcases.

The piston, specifically designed for larger bores, is made of aluminum alloy and engineered to handle the higher mechanical and thermal loads generated by this configuration. The technical package also includes a molybdenum disulfide-coated skirt, DLC-coated pin, and chromium nitride-coated special steel piston rings, with the aim of optimizing sliding performance, wear resistance, durability and operating consistency. The gasket set, specifically developed for each Big Bore Extreme application, completes the system by ensuring assembly precision, full compatibility with the kit, and resistance to the high temperatures generated by off-road use. dall’utilizzo off-road.

On the electronics side, the system is completed by GET Boost, the pre-configured hardware module developed in collaboration with GET, the Group's electronics brand, to work in combination with the cylinder kit. This solution allows the stock ECU to be retained while optimizing combustion management and fueling strategies, thereby maximizing the performance potential unlocked by the cylinder kit.

The Big Bore Extreme range is currently available for the following applications:

Honda CRF250R, model years 2018-2026

Yamaha YZ250F, model years 2019-2024

Kawasaki KX250, model years 2023-2026

KTM 250 SX-F and Husqvarna FC 250, model years 2016-2022

GasGas MC 250F, model years 2021-2023

With the Big Bore Extreme range, Athena strengthens its position in the off-road aftermarket with a highly technical solution developed with a system-based approach and designed to turn a new riding experience into reality.

Reality begins now.