Two Stroke Motocross
Two Stroke Motocross Forum => General Two Stroke Talk => Topic started by: JohnN on January 18, 2010, 08:56:25 AM
-
Dear MXA,
Have you dyno tested the KTM 144SX? Have you compared it to the KTM 125SX? Have you tested it against 250 four-strokes?
Yes, yes and yes. Where the 125SX has a smooth, linear and road racy powerband, the 2008 KTM 144SX powerband is much chunkier off the bottom and through the middle. 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), 144SX (18.9 ft-lb) and 250SXF four-stroke (19.2 ft-lb). The 144SX closes the torque gap, which is what four-strokes use to get hooked up better than two-strokes. The 144SXâ??s additional torque is more important on the track than its horsepower figures.
The horsepower numbers favor the 144SX over the 125SX (and over the 250SXF also). The 2008 KTM 144SX tops 40 horsepower at peak (which is about 300 rpm lower and two horsepower more than the 125SXâ??s peak). Best of all the 144SX makes as much as three horsepower more than the 125SX in the meat of the powerband.
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 144 a better bike to go up against four-strokes.
Do we think it will beat a 250 four-stroke? Weâ??ve seen guys on weak RM125â??s win Vet races against riders on 450s. So, anything can happen. The 144 can beat them when used to its fullest. It will definitely beat a 125.
-
Thus, why I was turned down when asking to allow them in the 250f class for 2010.
-
hi please excuse my ignorance ,but who was it that actually turned you down :)
-
I can't say, but it basically meant the rules wouldn't be changed by ProAMA. You may be able to figure it out from this 27 pager... http://www.vitalmx.com/forums/Moto-Related,20/Hey-DC------250-two-stroke,628026?page=19 (http://www.vitalmx.com/forums/Moto-Related,20/Hey-DC------250-two-stroke,628026?page=19)
-
i got it.Thanks mate :)