01. Engine & Exhaust
The 2023 KTM 450 SMR boasts one of the most manic 4-stroke powerplants in the paddock, with its SOHC engine proving to be the perfect example of advanced engineering. For 2023, the engine is tilted 2° backward with a lower front sprocket position, which together with the benefits of mass centralization and reduced engine weight make the anti-squat behavior of the chassis second to none. With massive power output and an overall engine weight of only 59 lb, you'll dominate the competition apex after apex.
A completely redesigned SOHC cylinder head makes for a more compact and lightweight package, using a shorter profile with the camshaft located closer to the center of gravity. Lightweight valves are actuated via a DLC coated rocker arm with optimized timing, specifically designed to deliver precise levels of torque and throttle response. The diameter of the inlet valves is 40 mm, while on the exhaust it is 33 mm. Redesigned intake ports allow higher flow coefficients, resulting in a more efficient and powerful engine, with a new valve cover reducing the number of mounting screws, and a single oil spray jet guarantees efficient cooling while keeping the weight low.
Designed with weight reduction and performance in mind, the crankshaft in the KTM 450 SMR engine improves throttle response and contributes to the lightweight feel of the motorcycle. The perfect balance of rotating masses is achieved by balancing the weights of the crankshaft flywheel, and the new rotor, and thanks to the innovative counter balancer shaft, engine vibration is kept to an absolute minimum.
Crankcases and engine covers
The KTM 450 SMR engine is designed with mass centralization and weight reduction as the main criteria. As a result, the crankcases have been designed to house the internal components of the engine in the perfect position to achieve an ideal center of gravity, while adding the least possible weight. The cases are manufactured using a high-pressure die-cast production process, resulting in thinner but more reliable wall thickness. And just to add a little extra - the KTM brand logo gives the black powder-coated engine cover the ultimate READY TO RACE look.
The KTM 450 SMR features a SUTER slipper clutch which prevents rear wheel instability and hopping when braking hard into the apex of a turn, for maximum control and perfect Supermoto-style drifting. The Brembo hydraulic system guarantees perfect clutch modulation.
The redesigned lightweight 5-speed transmission is produced by Pankl Racing Systems ensuring the highest level of durability and reliability. The redesign focused on a weight-optimized shift shaft, reducing the operating force of gear changes, best suited to the revised transmission ratio (29:72). The gear shift lever also features an anti-dirt build-up design that keeps the lever tip in its original position - even in the toughest conditions.
Engine management system
Developed by Keihin, the EMS is specifically designed to be small, light, and lightning-fast at processing data. It integrates the launch control for perfect starts, selectable engine maps via the map select switch on the handlebar, traction control as well as the Quickshifter function. It is also combined with the gear position sensor, which optimizes power delivery for each gear, while a roll-over sensor (ROS) kills the engine in case of a crash, adding a nice safety feature to the KTM 450 SMR. The hourmeter now also features an integrated EFI status LED and fuel level indicator, so you know when it's time to pull into the pits for a refuel.
Cylinder and piston
The lightweight aluminum cylinder features a 95 mm bore and 63.40 mm stroke, housing a CP bridged-box-type piston weighing a meager 327 g. The piston features anodized annular grooves, adding durability and longer service intervals, with the compression ratio increased to 13.1:1 for added peak performance.
The multifunctional side-mounted balancer shaft masterfully balances all the oscillating forces, while also driving the water pump. It effectively keeps engine vibrations to a minimum, resulting in the smoothest ride, even at the highest engine speeds.
A combined start/stop switch on the right side of the handlebar allows for an easy and intuitive function - not that you'll ever want to turn your KTM 450 SMR off.
The KTM 450 SMR exhaust system is expertly designed to deliver class-leading performance at the lowest possible weight. Featuring a flow-designed resonance chamber integrated into the 2-piece header, the header remains as compact as possible with the joining position allowing it to be removed without having to take out the shock absorber. Further innovation allows for a short, lightweight aluminum silencer without increasing noise levels.
The KTM 450 SMR radiators are expertly crafted using high-strength aluminum and CFD (computational fluid dynamics) to channel air through the radiators more efficiently. The cooling system is integrated into the frame allowing for improved cooling by channeling coolant through the frame while eliminating the need for additional external hoses, while a large center tube running through the frame reduces the pressure in the system allowing for a more consistent coolant flow. An internal thermostat for added reliability is fitted as standard.