The world championship winning KTM 250 SX-F is remarkably similar to its production model brother in many ways but the motorcycle used by Tom Vialle, Rene Hofer and Mattia Guadagnini carries special parts and mods to make it comply 100% to the increased needs of those Red Bull KTM Factory Racing riders when they are out chasing for MX2 class victories. Even more Ready To Race with extra and individual fine-tuning for Grand Prix competition. We sourced some time from the Red Bull KTM Factory Racing team to find out what, where and why…

Red Bull KTM Factory Racing’s Tom Vialle aboard his KTM 250 SX-F in Maggiora, Italy
PC @RayArcher

The #28 KTM 250 SX-F is gleaming under the race team awning at the FIM Motocross Grand Prix of Italy. Several hours after our investigation into a few areas of how the MX2 bike is ‘factory’, the same machine was used to seize victory for the second time from three events in 2021 and head the world championship standings with Guadagnini securing the red plate. Competing in the toughest arenas in the world, these race bikes are also the development vessel for future production models.

Mattia Guadagnini on his way to victory in Maggiora, Italy
PC @RayArcher

In the search for a thoroughbred race bike among the entire offroad world then the KTM 250 SX-F would have a very strong claim. It first surfaced in 2003 and won the inaugural MX2 world championship in 2004. Since that year it has gathered a further 12 titles with eight different riders. It has ruled MX2 every season since 2016.

Compared to the MXGP class – where the 450cc engines produce more than enough power and speed for current 1.6km Grand Prix tracks while also being primed for rideability – the MX2 250cc motors are tuned for every shred of maximum output and horsepower. The factory machinery is in the ‘ball-park’ for the minimum weight limit permitted by the rules due to the components that are used for set-up (electronics) and those added to gain durability, and ensure reliability and performance at the sharp end of the sport.

Tom Vialle’s mechanic Harry Norton in the pit box
PC @RayArcher

How do Red Bull KTM prepare the motorcycle for battle? We asked Tom Vialle’s mechanic Harry Norton for a quick tour of the special elements of the #28…

Handlebars – clutch and throttle bodies

“The clutch housing is a factory Brembo part that has the mounting on the back of the handlebar instead of the top. It’s designed to be stronger, there is more material and it is made from one-piece billet. We gain a lot of strength with this. It’s coated, so it looks a bit cooler as well.

The clutch housing on Tom Vialle’s KTM 250 SX-F is made from one-piece billet
PC @AdamWheeler

On the throttle side the standard part is casted but ours is a machined billet aluminum throttle housing. It’s also made for strength and there is no chance of it breaking in a crash (which could be the difference between winning and losing a championship).

The aluminum throttle housing is extra strong for the racing needs of Grand Prix
PC @AdamWheeler

We order a bunch at the start of the season but we need very few. It is also a part that isn’t made for everyone. Every race bike has one and that will do for the full season. They don’t break, so the only reason to change it would be in the event of a big crash that scratches it up.”

Tom Vialle’s bike has a machined billet aluminum throttle housing
PC @AdamWheeler

Rear brake lever tip

“This is 3D printed titanium, so it is quite new technology. It looks the same as the standard part but it’s extra-strong and super-durable. It’s designed to withstand big hits that are more likely at this level. We’ve only had 3D titanium printing since last year.

The rear brake lever of Tom Vialle’s KTM 250 SX-F is 3D printed titanium
PC @AdamWheeler

Tom has welded titanium for the actual footpegs because he prefers the different shape; the foot-bed and the diameter is a bit different. Tom’s set-up generally is very neutral. There is nothing too crazy about his handlebars, brakes and other controls. It’s all quite calm, just like him really.”

Tom Vialle’s footpegs are welded titanium
PC @AdamWheeler

Rear and front brake guards

“Kite make a rear brake mount for us so we can have two fixed billet aluminum mounts for our carbon guard which stops the caliper from getting hit or being damaged in a rut when, say, the pistons can get pushed back.

The carbon guard stops the caliper from getting hit or being damaged
PC @AdamWheeler

We also have one for the front end of the bike where we want that bit of extra protection to stop the calipers being pushed in and losing the front brake.”

On the front, the carbon guard prevents the calipers from being pushed in
PC @AdamWheeler

Header pipe

“This is one of the coolest things on our bike. We have a cast titanium header pipe section. The exhaust port comes out with the standard Akrapovič titanium but then this section is aligned to the engine. Instead of using springs it is bolted into place and, like many things we change, it is stronger for Grand Prix competition. We can match the engine characteristics to the exhaust pipe. I think Akrapovič are the only company doing this because it is quite a process to cast. It’s not so easy. This piece gives us more peace of mind because there is less chance of something unpredictable happening to the engine if the bike gets hit.

The KTM 250 SX-F of Tom Vialle has a cast titanium header pipe section
PC @AdamWheeler

Everything we do on the bike is to minimize risk. We want to lower the potential of something breaking as much as we can and sometimes means we have to gain weight…but we get more of a guarantee. We need that protection because in this level of racing there are more hits, more punishment for the material and more contact with other riders. You are always trying to make something stronger.”