Stay away from the ‘17’s. They had case issues that would break off the starter gear boss. Unless they already replaced the case or did the “fix” for it. Jetting sucks on either bike and needs addressed, there is a thread for it.
As for chassis I have a ‘18 250sx and a ‘22 350sx. Yes the newer forks are way better, but if you’re a faster rider you’ll be hunting for front end grip no matter what year with the air forks. I have cone valves and Luxon clamps on my 350 to stiffen it up more and it helps a lot. It’s hard to explain, but stiffer forks and clamps that are torqued lower to allow more flex makes the chassis more compliant through the rough stuff. I’ve ridden the ‘18 with cones as well and Neken clamps and feel that it’s pretty close to the same as the ‘22. Where you notice it the most is hard pack. Width wise I don’t really notice a difference when riding. Yes the ‘19+ is narrower, but in either case there is so much other stuff to focus on when haulin the mail you don’t really notice.
For reference I’m 5’10 175lbs. without gear fast 35+ vet. Drop the forks to the 3rd line on new AER’s or new cones, the second line on the old cones (they are 5mm shorter) and set sag to 103-105mm with the proper spring for your weight and speed. If you have stock clamps back the lower pinch bolts to 9nm from the stock 12nm and you’ll notice the difference in rough sections immediately. Also if it’s real rough back the high speed compression on the shock out 1/2 turn and it will help a ton.
2018 KTM 250sx 2022 KTM 350sxf
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