The 2021 KTM motocross and supercross lineup consists of six motorcycles—three each of four-strokes and two-stroke.The four-stroke models are the 450 SX-F, 350 SX-F, and 250 SX-F, while the two-strokes are the 250 SX, 150 SX, and 125 SX. Most of the changes for 2021 apply to all six models, though there are some exceptions. Let’s take a quick look at the updates to the 2021 KTM motocrossers and supercrossers.
All six 2021 KTM SX-F models get a new WP Xact fork. While the fork remains an air-spring design, it gets new internals. The bypasses have been enlarged “to reduce pressure peaks,” according to KTM. Complementing that is a smaller rebound spacer in the air leg. That means more air volume in the negative chamber and a more linear action with a spring-style feel. Theirs is also a new mid-valve damping system that KTM says improves feedback and feel. Overall, the new WP Xact forks are claimed by KTM to have “refined performance, comfortable, and handling.”
The WP Xact shock also gets a minor update. There’s a new link-piston O-ring, which KTM tells us will “reduce fading and improve consistency over long motos.”
There are new SKF bearing seals in the linkage for freer movement. KTM says this results in “better suspension feel and performance throughout the shock stroke.”
With the suspension and linkage updates comes new settings. KTM isn’t revealing what’s new, but the company does say the result is “better traction, improved comfort and confidence-inspiring feel.”
Dunlop Geomax MX33 tires are now shod on the Excel rims.
The SOHC KTM 450 SX-F gets some motor updates not found on the DOHC 250 and 350. There’s a new con rod with a copper-beryllium upper bush for faster revving, along with new rocker arms up top for the titanium valves. The mapping has been changed to punch up the low-end power, and map 2 is now the “extreme performance option,” according to KTM. Also, the 450 gets a new hour-meter casing.
The two-strokes get two changes you won’t see in the four-strokes. Still working with carburetors, the 250 SX, 150 SX, and 125 SX have a new smoother roller-action throttle assembly. Also, the inner clutch hub sleeves are thicker to beef up reliability.
KTM gives the 2021 125 SX a new piston. It is made of a harder material to increase durability while maintaining performance.
This week, Senior Editor Nic de Sena rides the all new Ducati Monster. Big changes have been made by Ducati–has the company ruined the considerable heritage of the iconic Monster–or are the changes worth it? In the second part of the show, we chat with Nick Ienatsch, Founder and Head Instructor at the Yamaha Champions Riding School. He says: “We aim to change your riding life by introducing you to Champions Habits: The techniques, approaches, skills, and the mindsets of the best riders in the world. These Champions Habits are the foundation of safety and consistency to whatever speed you ride, in any venue on any bike. Street riders, this is just as much for you as track riders. The best way to make safe riders is to make good riders.“ We hope you enjoy this episode!