Alright, buckle up, because I’m gonna tell you all about my little speed run with the KTM 125 SX. This ain’t no scientific test, just a dude messin’ around with his bike and sharing the results.
First off, I needed a place to actually TRY this. No way I’m doing this on some crowded street. Found a long, pretty straight stretch of paved back road out in the boonies. Made sure there were no cops, cars, or clueless pedestrians. Safety first, ya know?
Before I even started, I warmed up the bike properly. You gotta treat her right! Let it idle for a few minutes, then did a few slow laps to get the engine temp up and the tires a little grippier. No point in wrecking the engine before I even hit top speed.
So, here’s what I did: I started off slow, shifting through the gears like normal. Then, once I got to about 3rd gear, I started really pinning it. I mean, FULL throttle. Gotta lean forward a bit to keep the front wheel down, this thing is a beast for a 125! Kept clicking up through the gears as fast as I could, trying to keep the RPMs in the sweet spot.
I was using a GPS speedometer app on my phone to track the speed. Not the most accurate thing in the world, but it’s good enough for a rough idea. I tucked in as much as possible to reduce wind resistance – looked like a total dork, I’m sure, but hey, gotta go fast!
Now, the moment of truth. After a few runs, going both directions to account for any wind, the highest speed I saw on the app was around 72 mph (about 115 km/h). Not bad for a little 125 two-stroke!
Of course, there are a bunch of things that could affect the top speed: my weight, the tire pressure, the condition of the engine, the alignment of the stars… you name it. But based on my totally unscientific test, that’s what I got.
- Bike: KTM 125 SX (stock engine)
- Location: Straight, paved back road
- Method: Full throttle, GPS speedometer app
- Top Speed (indicated): ~72 mph (115 km/h)
Would I recommend trying this yourself? Only if you’re comfortable riding at those speeds and you’ve got a safe place to do it. And PLEASE wear proper gear! A helmet, gloves, and jacket are a must. Don’t be an idiot.
Anyway, that was my little speed adventure. Hope you found it interesting! Now I gotta go clean the bug splatter off my helmet.
