WE RIDE AIDAN ZINGG’S LORETTA-WINNING KTM 112SX SUPERMINI

Aidan Zingg won the Supermini class at Loretta’s and earned a ride with Team Green because of it. He’ll be on the KX250 in 2025.

How many 14-year-olds understand how their carburetor works? “Hey, Dad, the bike is too lean. When you hold it wide open through a long sweeper, let off mid-air and get back on the gas, there’s no fuel left in the float bowl.” This was our favorite quote from our day of testing with Aidan Zingg. 

We know Aidan’s Dad, Bob Zingg, from his days of racing and running “Zingg Graphics,” so we’ve watched Aidan grow up from a distance. Over the past few years, he’s always been at the front of the pack at the races, but he’s been overshadowed by other standouts in Southern California. This year, Aidan stepped up his program to another level. He hired trainer Dimitri Rolando, and he signed up to help the American-based KTM R&D team as they developed the new 2025 KTM 85SX. Aidan was already a good test rider, and through working with Casey Lytle, Ryan Morais, Leigh Crawford, and Damon Conkright, he truly came into his own as a young testing prodigy. 

AIDAN WAS ALREADY A GOOD TEST RIDER, AND THROUGH WORKING WITH CASEY LYTLE, RYAN MORAIS, LEIGH CRAWFORD, AND DAMON CONKRIGHT, HE TRULY CAME INTO HIS OWN AS A YOUNG TESTING PRODIGY.

Aidan won his first major AMA Amateur National Championship in the 85 class at Mammoth in 2023, and then he won again at Mammoth this year in the Supermini class. However, he’s racing against kids who have won a lot more than just two championships, and previously, his best moto finish at Loretta’s was a fifth place in the 65 class three years ago. Last year, Aidan was 9th and 11th overall in the 85 (12–14) classes, so he wasn’t considered a favorite going into Loretta’s this year in the Supermini division. After winning at Mammoth, Aidan wanted to win at Loretta’s, and he made it happen when it counted most. He went 5-1-1 for second overall in the Supermini 1 class and went 1-3-1 for first overall in the Supermini 2 class. It was a life-changing experience for the young Californian, putting him in the spotlight for the first time, and proving that hard work pays off. 

Now that Aidan is officially making the move up to big bikes, he and his dad were happy to share their KTM 112SX Supermini secrets with the world. 

Our test riders had no idea a mini bike could be so fast.

LEARNING ALL ABOUT THE CHASSIS

Interestingly enough, KTM did not give Aidan any race support from their Orange Brigade program, but the R&D department was able to help him out. As compensation for their time and help in developing the new bike, the Zinggs were given the option of pay, A-kit suspension or help in developing his stock suspension using the infinite resources only available through WP. Surprisingly, Aidan and his dad chose help setting up their stock WP components. Aidan has done extensive testing on the forks and shock with the WP Pro Components and cartridge drop-in kits, but he prefers the stock suspension with the WP air forks. While each option has its advantages, there are inherent aspects of the air forks and shock that he likes and thinks outperform the others. 

Bob said, “We have both learned so much about pressure balance and hysteresis that it will make your mind spin.” Ultimately, Aidan proved that anyone who buys a KTM can win at the highest level using the stock components. The WP in-house crew valved his suspension, and he ran the air pressure at 74 psi (5.1 bar) and the sag at 118mm. 

The custom-welded swingarm.

Aidan also found that he preferred the balance of the 2025 prototype. He said it feels much more rigid and planted in the rear end, something that’s a plus for the fast kids who push the bike’s limits. Aidan and his dad knew they couldn’t race the new model, but they could learn from it. They noticed the size and shape of the rear swingarm and decided to replicate it on their current bike. To experiment, they bought a swingarm off eBay and added a 10-inch plate on the underside, similar to the shape of the 2025. They also added material around the shock pocket and rear-wheel pocket, trying to make it more rigid like the prototype Aidan had been testing. After some trial and error, they got something they felt was significantly better, giving Aidan a little more control on rough entries and helping with straight-line stability. They also tried stiffer head stays and a very rigid skid plate. Aidan didn’t like the skid plate but kept the head stays.

THE LYNKS RACING ENGINE PACKAGE

The Zinggs use Lynks Racing for their Supermini engine, but they made mods of their own. “It’s very important to make sure your kid understands what detonation sounds like. In my experience, this was our most valuable tuning tool. Even running the suggested specs from Lynks, we would pick up just a bit of detonation at the crack of the throttle,” Bob explained. “This would limit how lean I could get the jetting and force me to add more base gaskets to lower the compression. Unfortunately, this would change port timing and change the power characteristics. At that point, we ditched the modified head and went back to the stock setup with the interchangeable domes. I had four domes cut in different depths so that I could adjust compression without moving port timing and find the right balance of compression, jetting and fuel. This also had the added benefit of some additional top end. At that point, we felt very confident in our engine setup.”

The Zinggs used Lynks Racing for their engine, and then made even further mods themselves.

To complement the Lynks-built engine, they used an HP Performance-tuned GET ECU. Bob said, “There is no combination of engine package this unit doesn’t improve power with—everything from a basic 105cc to a full-mod 112cc Supermini. I even have a Pro Circuit-built 112cc engine we tried it on, and although it had the least effect on that motor, it was still noticeable. Using the data HP Performance provided, I could also get rid of some other things I had been looking to try, like venting the airbox, super-tight silencer packing and the FMF big-bore pipe. All of those mods made the same or less power.”

AFTER SOME TRIAL AND ERROR, THEY GOT SOMETHING THEY FELT WAS SIGNIFICANTLY BETTER, GIVING AIDAN A LITTLE MORE CONTROL
ON ROUGH ENTRIES AND HELPING WITH STRAIGHT-LINE STABILITY.

The carburetor isn’t stock, either. Bob bought this bike from James Coy, who had multiple Pro Circuit-modified carburetors. Boring the 28mm Keihin carb out to 30mm is pretty standard for a mod bike, but with a closer look, you will see there is no choke. It looks like the carburetor is about to fall out of the air boot. This mod brings the carb closer to the reeds and lengthens the rear. In back-to-back tests, Aidan preferred the quicker throttle response from the shorter carb.

The carburetor mods were inspired by Pro Circuit.

Internally, Aidan used a Hinson clutch basket with the stock pressure plate in the number-two setting using solid pins. For fuel, the Zinggs used a new company called “Fuel Factory,” which was started by a few employees who left VP. They ran Fuel Factory’s MRX2 blend (a copy of MRX02) with Maxima K2 pre-mix at a 32:1 ratio. Of course, FMF Racing’s pipe and silencer finished it off. 

Aidan’s Supermini was incredibly explosive off the bottom end as MXA test rider Amari Arnold soon found out.

THE CONTROLS MAKE A DIFFERENCE

Some extremely cool upgrades on Aidan Zingg’s Supermini were the clutch and brake components. The stock KTM 85SX comes with Formula components, and for riders like Aidan who push their bikes to the limit, the stock brakes will fade once they heat up. From the outside, the Formula components almost look like a copy of Brembo units, but they aren’t the same quality. Aidan and his dad swapped them out for Brembo big-bike components. The stock KTM big-bike front brake mounts right on with no mods needed, while the factory Brembo rear brake required some work. You need to use the stock hanger and a big-bike caliper, then you have to drill out and grind the master cylinder to space out the lever pivot. The clutch is also a big-bike setup, but you need to use the 125SX unit (it says “#09” on the bottom of the master cylinder), not the 250/350/450 unit, which is marked “#10.” The unbelievable brakes were paired with a T-Rex throttle housing, taking the controls on this Supermini to the next level. Aidan prefers how smooth and easy the T-Rex throttle is to twist.  

Aidan is a pretty tall kid for a Supermini, so he ran the T-Rex top triple clamp with custom 50mm bar risers to get his Renthal 827 bars where he needed them. He used the stock footpegs, but with custom-cut teeth that were sharper. He also trusts in FasterUSA wheels and runs Dunlop’s MX34 tires. 

Aidan’s white steel frame and rear fender help his Supermini stand out from the pack.

ON TRACK PERFORMANCE

When it was time for our young tester, Amari Arnold, to hop on the bike, Bob asked, “Hey, Amari, do you know what detonation feels like?” Built two-strokes require extra upkeep, but Superminis are especially high maintenance. Parents should be careful what they sign up for when sending an 85cc engine off to be bored out to a 112cc Supermini. Short maintenance intervals and race gas will lighten your wallet quickly! Of course, teaching little Johnny to speak up whenever the bike doesn’t sound normal is beneficial as well.

AT THE END OF THE DAY, THE BIKE WAS AMAZING. THIS WAS THE FASTEST 112CC SUPERMINI WE’VE EVER TESTED, BUT WE WERE MOST IMPRESSED WITH AIDAN’S PERSONALITY AND MECHANICAL KNOWLEDGE.

In motion, Aidan Zingg’s KTM 112SX Supermini was a rocket ship. Amari did a wheelie down the start, and it looked like the bike was ready to take flight. Amari knew Aidan’s bikes were fast, because he had been racing against him all year, but he was blown away by how fast it was. MXA’s Josh Mosiman also tested the Supermini back to back with our 2025 Husqvarna TC125, and the Supermini blew the big bike out of the water. The power-to-weight ratio of the Supermini with smaller wheels made it considerably faster than the 125, and of course the 112cc isn’t fuel-injected, which means you won’t be hitting the rev limiter. Even going wide open up the hills and down the start at Glen Helen, we couldn’t get the Supermini to stop pulling. It just wanted to keep making power. Not only was it fast, the bottom end was incredibly snappy, allowing our testers to pop a wheelie any time, anywhere. 

Amari expected Aidan to be running stiffer suspension, but he was surprised that it was fairly soft and plush. The Brembo 125SX clutch was also easier for Amari to pull in than the stock Formula hydraulic clutch he has on his personal TC85. Normally, he has to use two fingers on the clutch, but with Aidan’s setup, he could use just one. 

Aidan runs the stock WP XACT air forks with a T-Rex upper triple clamp and a big-bike Brembo front brake.

At the end of the day, the bike was amazing. This was the fastest 112cc Supermini we’ve ever tested, but we were most impressed with Aidan’s personality and mechanical knowledge. He was able to explain in detail how he and his dad tested and built his KTM 112SX Supermini, explaining the ins and outs of each mod they made and why he chose each part. It’s easy to stereotype the youth of today when you see them glued to their phones, and it can be equally sad when you meet a young teen who rarely gets the chance to talk because his parents always speak up for him; however, getting to know Bob and Aidan was a breath of fresh air. We hope this kid goes far, and we’re excited to do more testing with the Zinggs in the future.

Aiden Zingg’s KTM SuperMini was one of a small handful of miniycles to ever make the cover of MXA. This is the January 2025 issue.

MXA VIDEO: INSIDE SECRETS OF AIDEN ZINGG’S KTM 112SX SUPERMINI