ASK THE MXPERTS:
KTM 150SX vs. KTM 125SX
Torque is up two foot-pounds from 6000 rpm to 10,000 rpm (and one foot-pound until sign-off). A more telling comparison is between the torque of the 125SX (17.8 ft-lb), 150SX (18.9 ft-lb) and 250SXF four-stroke (19.2 ft-lb). The 150SX closes the torque gap to the four-stroke, which is what a four-stroke uses to get hooked up better than two-strokes. The 150SX’s additional torque is more important on the track than its horsepower figures.
If we were going to choose a 125 two-stroke to race against 250 four-strokes, we would choose a big bore. The extra horsepower and torque (especially the torque) make the 150 a better bike to go up against four-strokes.
Do we think it will beat a 250 four-stroke? We’ve seen guys on weak RM125′s win Vet races against riders on 450s. So, anything can happen. The 150 can beat them when used to its fullest. It will definitely beat a 125.
The March 2009 issue of MXA has a full test on the 2009 KTM 150SX and 250SX.