FRIDAY’S USED MOTOCROSS BIKE GUIDE: HOW TO SETUP YOUR 2009 KTM 450SXF:

1. Forks. The stock 2009 KTM forks were acceptable (good spring rate and adequate damping), but we switched to Showa works forks (can you blame us?) and had Pro Circuit valve them to our specs. www.procircuit.com

2. Shock. On the stock WP shock we replaced the stock 7.2 kg/mm spring with a 7.6 kg/mm spring. This was a big improvement for riders above 175 pounds. We also tested an Ohlins TTX-44 shock (very good) and a Showa works shock (both with 7.5 springs). In the end, we elected to have MX-Tech revalve our WP shock. This was the best setup. www.mx-tech.com

3. Gearing. Fast testers added one tooth on the back (14/53). This was a good move for everyone above Novice. There is one uniquely different gearing trick; some test riders decided to gear the KTM taller (14/51). Why? Gearing it taller eliminated the need to shift. It made first gear feel like second and third like fourth. It almost made the KTM into a two-speed bike.

4. Subframe. We cut our subframe struts by 4mm to lower the rear of the bike by 15mm. Most test riders felt that the KTM was too tall.

5. Seat. We cut the seat foam down by one inch, but KTM offers an option low seat if your don’t feel like doing the work yourself. This made the bike lower, but a lot more uncomfortable.

6. Carburetor. We added an R&D Powerbowl2 and an R&D Flex-Jet to gain not only an adjustable fuel screw, but an adjustable leak jet (the 450SXF does not come with a leak jet). www.r1dean.com

    Main: 182
    Pilot: 40
    Needle: OBDTP
    Clip position: 4th from top
    Fuel screw: 1-3/4 turns (1-1/2 turns stock)
    Notes: We had a cough at low rpm that we couldn’t iron out with the fuel screw or needle. We set the accelerator pump adjustment screw exactly one turn out from contact with the pump cam. That fixed it.

7. Exhaust pipe. DR.D’s KTM pipe tucks completely out of the way and enhances the overall powerband (we had to re-weld it to fit on our cut-down subframe). www.dubachracing.com

8. Air filter. We originally ran Twin Air’s GP air filter kit with its aluminum cage, but had issues and return to the stock cage with a normal Twin Air filter. www.twinairusa.com

9. Plastic. We cut the rear fender/side panels to make the bike easier to lift up and replaced the stock radiator wings with Cycra Powerflow radiator shrouds. www.cycraracing.com

10. Miscellaneous. It is possible to save several pounds by switching to a lightweight battery (from TurnTech, Shorai or Super B). We clipped the gas cap locking tabs off and added a TM Designworks chain guide, www.tmdesignworks.com and STR rear caliper cooler. www.systemtechracing.com