KTM 2023 SX、SX-F Series
On May 10, 2022, KTM released the 2023 full-line commercial off-road racing (Motochross off-road) SX and SX-F series.
The whole 2023 series has been updated with up to 12 models: full-size models, including 250 SX-F, 350 SX-F and 450 SX-F with four-stroke engines, and 125 SX, 250 SX and 300 SX with two-stroke engines; 85 SX large wheel version (front 19, rear 16 inch wheel frame), 85 SX small wheel version (front 17, rear 14 inch wheel frame), 65 SX, 50 SX, 50 SX Mini and electric small off-road SX E5 for children/teenagers.
In addition, a 2022 version of 50 SX Factory Edition is added.
The six models (250 SX-F, 350 SX-F, 450 SX-F, 125 SX, 250 SX, 300 SX) belonging to the full-size off-road racing bike are all new products, and the engine, frame/chassis and body are all new designs. In the past two years, the demand for Off-Road products in the European and American markets has increased significantly, which may be one of the important reasons for KTM to comprehensively update its product line. For various manufacturers, MX field off-road racing is the basis of various subsequent extension models. Enduro endurance off-road, Supermoto off-road (also known as skid tire) and even Rally rally racing are expected to be updated in succession.
Benefiting from the competition experience gained from the venues around the world, the 250 SX-F (corresponding to the MX2 level in the MXGP World Off-road Championships), 350 SX-F and 450 SX-F (corresponding to the MXGP level in the MXGP World Off-road Championships) equipped with four-stroke engines have been significantly upgraded from the inside of the engine to the key positions of the vehicle body.
Compared with the power unit, the frame and suspension system of six full-size vehicles have more versatility. The newly designed frame, after mechanical calculation, has new longitudinal and bending characteristics to improve the feedback of the vehicle to the rider, energy absorption and stability of linear acceleration: the main means are thicker main beam wall of the frame, forged steering shaft connecting end of the frame, etc.
The new supporting suspension system is equipped with hydraulic stop block (limit ring of fork core) on the front fork, which provides better resistance to bottom sinking, improves the progressive damping of the front fork in the process of movement for the last 40 mm stroke of the front fork, and allows the front fork to stay at a lower position at the end of the stroke of the front fork, making the subsequent acceleration more stable. The single-tube rear shock absorber adopts a split structure to achieve a gradual damping.
In terms of power unit, 450 SX-F maintains the original SOHC four-valve type, the cylinder diameter and stroke are still 95 mm x 63.4 mm, but adopts a new valve distribution structure (cylinder head), new crankshaft and piston; 350 SX-F also maintains the type of DOHC four-gas valve, with a cylinder diameter of 88 mm x 57.5 mm and stroke; The 250 SX-F adopts a new 81 mm x 48.5 mm cylinder diameter, stroke (78 mm x 52.3 mm in the previous version), and the whole engine core components including the valve system, piston, crankshaft, etc. are updated.
The biggest change of 125 SX, 250 SX and 300 SX with two-stroke engines is the full replacement of TPI electronic fuel injection system (formerly carburetor). The 300 SX is a brand new model. Previously, KTM had a two-stroke engine with a maximum displacement of 250 SX in the product line of MX off-road racing.
Compared with the previous version, 125 SX and 250 SX maintain the original engine cylinder diameter and stroke, and the cylinder diameter and stroke of 300 SX are also the same as the 300 EXC TPI in Enduro endurance off-road. But inside the engine, the cylinder, crankshaft and clutch are all new designs.
