Let’s face it, we all get excited when we see a 125cc two-stroke motocross bike roll out at the track. They are just one of those models that scream fun, and hey, they also do a whole lot of screaming out on the track! I have personally spent a lot of time aboard 125cc two-strokes in recent years, so for me to get the chance to ride the latest and most developed on the market today, you can guarantee I was excited.

The 2017 KTM 125 SX is one crisp looking machine, there’s no doubt about that. Featuring the same bodywork and ergos as the rest of the 2017 motocross range, the 2017 125 SX is far from an afterthought in the KTM range. It’s great to see KTM continue to push their two-stroke motocross range to ensure up and coming kids have a high-level stepping stone into the full-size four-stroke models.

I’m sure you’re all waiting for me to let you know how the bike performed on track, but first, let’s take a look at some of the specs and updates for MY17. Weighing in at just 87.2 kilograms, the 2017 KTM 125 SX is a very light and nimble machine. Using a lightweight chrome-moly steel frame, KTM engineers were able to create a frame one kilogram lighter than its closest competitor on the market.

Image: Alex Gobert (Foremost Media).

Not only is the frame considerably lighter than any of its competitors, KTM enhanced handling, stability and cornering at the same time. High torsional rigidity and low longitudinal stiffness also results in better absorption of the energy created from the front and rear suspension. The result of this? Less rider fatigue and more time spinning laps on the ball of fun!

For 2017 one of the big stories when it comes to the KTM range and the 125 SX is the addition of the new WP AER 48 air forks. As I mentioned, the KTM 125 SX isn’t an afterthought in their range, it receives all of the latest updates along with the rest of the models. The WP AER 48 fork has been added for multiple reasons, weight reduction, improved performance and ease of adjustment.

Using a split fork with separate functions for each leg, the aim with this design is to prevent loss of air pressure. Should the outer seal start to leak, the internal cartridge pressure will keep the bike in position. The air fork is also super easy to adjust to any rider’s weight via a single air valve on the side of the track. This was very apparent on the day as KTM Australia’s Danny Apro was able to perfectly massage my settings to suit my style and needs.

Image: Alex Gobert (Foremost Media).

After locking in our rear shock settings and a rider sag of 108mm right off the bat, it only took a few trips to the pits and we had our fork settings feeling great. In the end I settled on a fork setting of 16 clicks out on the compression, 17 clicks out on the rebound and an air pressure of 7.4 bar. This setting allowed the 2017 KTM 125 SX to really turn in well and give me a lot of confidence in the front-end.

As I’ve mentioned before, I’m obviously not a pro level rider, and I don’t like to hang it out on the edge at all. I like to steer the bike from the front more than the rear and remain in control at all times. With the WP AER 48 fork I was able to find that comfort level I needed very quickly without too many changes at all. This is where these forks really come into their own, the ease of adjustment is just too good, you can change the whole feel of the bike in seconds.

Not only are the WP AER 48 forks easy to adjust, they more importantly work very well on track. This fork update is a huge step ahead over the previous 4CS units and is sure to be a welcomed change for any rider who swings a leg over the 2017 KTM 125 SX. The chassis and suspension combination for 2017 is hard to beat; it’s really an impressive setup.

Image: Alex Gobert (Foremost Media).

Powering this solid combination down the track is the 125cc two-stroke engine that weighs in at just 17.2 kilograms. Using a compact cylinder with a 54mm bore, the 2017 KTM 125 SX features a cutting-edge power valve unit with a sophisticated mechanism for the lateral exhaust ports. You can also increase the displacement of the MY17 125 SX to 144cc just by replacing the cylinder, piston and head thanks to the skilfully designed crankshaft.

For 2017 the KTM 125 SX now features a new Mikuni TMX carburettor, replacing the previous Keihin offering. This new 38mm flat slide carb is designed to provide smooth and controllable power all the way through the rev range. It’s also less sensitive to various altitudes and temperatures, which is a huge plus when it comes to riding your two-stroke at new locations.

The 2017 KTM 125 SX engine package is really impressive, it’s super fast for a 125cc two-stroke and you can tell it has been design with racing in mind. The engine wants to be revved and once you have it in the meat of the power, it pulls quite well, even with my 80-kilogram chassis sitting on top. I can’t forget to mention the sound also, this thing just sounds amazing!

Image: Alex Gobert (Foremost Media).

As I mentioned earlier, the 2017 KTM 125 SX also features the list of awesome features right out of the box in its ‘Ready to Race’ form. You’ll be greeted with a comfortable bend of Neken handlebars as standard, fitted with new ODI Lock-On grips for 2017. In addition, we again see Brembo brakes and a hydraulic clutch system featured for MY17 along with black Excel rims and in-mold graphics for increased durability.

The 2017 KTM 125 SX is one seriously fun bike, there’s no way you could take this bike for a ride and return without a huge smile on your face. If you’re a youngster looking to make the move from your 85cc bike, or you’re an adult like me looking to have a tonne of fun – this bike is what you’re looking for. The 2017 KTM 125 SX comes in at a recommended retail price of $10,795 and is now available Australia wide. Head to your local KTM dealer to check one out, or see www.ktm.com.au for more information.