If you've spent any time at a local dirt track lately, you've almost certainly seen a set of burris 33a tires mounted on the karts dominating the field. These tires have become something of a legend in the karting community, specifically for those who spend their weekends sliding around on dirt or hard-packed clay. They aren't just another piece of rubber; for many racers, they're the difference between a podium finish and a frustrating night spent chasing a setup that just won't "hook up."
The beauty of the 33a compound lies in its versatility. While some tires are very "one-note"—meaning they only work in a tiny window of temperature or moisture—the Burris 33a seems to find grip in places where other tires just spin. It's a slick tire designed primarily for dirt, but don't let that fool you into thinking it's a simple product. There's a whole science to how these things work, and if you want to get the most out of them, you've got to understand what makes them tick.
What Makes the 33a Compound Special?
In the world of Burris tires, the "33a" refers to the specific rubber compound used in the manufacturing process. Burris offers several different compounds, ranging from the softer SS-11s to the harder 55s, but the 33a sits in that "sweet spot" that racers love. It's hard enough to provide a stable platform and resist excessive wear, but it's soft enough to "punch" (a term racers use for the durometer reading) at a level that generates massive amounts of side bite.
When you're diving into a corner on a hard-packed track, you need the tire to deform just enough to grab the surface without rolling over on the sidewall. The burris 33a tires are famous for having a very predictable feel. You know exactly when they're going to break loose, which gives the driver a ton of confidence to push the limit. It's that feedback—that communication between the rubber and the driver's hands—that has kept Burris at the top of the food chain for decades.
Prepping Your Tires for the Track
Now, if you think you can just buy a set of burris 33a tires, bolt them on, and go win a trophy, I've got some news for you. Karting, especially on dirt, is 70% tire preparation. If you look into any pro's trailer, you're going to see stacks of tires and about a dozen different chemical jugs.
The 33a is a fantastic "canvas" for tire prep. Because the rubber is so consistent, it takes chemicals very well. Most racers will start by "scuffing" the tires. This involves a light sanding to get that factory glaze off and open up the pores of the rubber. Once the tire is open, that's when the magic happens. Whether you're using an internal prep to help the tire stay soft throughout a long feature race or an external "wipe" to give it that initial "fire" on the start, the 33a responds beautifully.
However, a word of caution: you can definitely over-prep these tires. If you soak them too much, they can become "mushy." When the rubber gets too soft, the tire will start to roll over, and you'll actually lose speed because the kart will feel "bound up" in the corners. It's all about finding that balance based on what the track is telling you.
Reading the Track Surface
One of the biggest mistakes newer racers make is sticking with the same tire strategy regardless of how the track looks. Burris 33a tires are absolute monsters on a "blue groove" track. If you see that dark, shiny line forming where the rubber has been laid down on the dirt, that's when you want to be on 33as.
They also perform exceptionally well on "slick-to-dry" surfaces. You know those tracks that start out muddy and heavy in the heat races but turn into a dusty, hard-packed surface by the time the sun goes down? That's 33a territory. If the track is still "heavy" or "tacky" (meaning it has a lot of moisture), you might find that a softer tire like an SS-11 works better. But as soon as that moisture starts to leave the clay, the 33a becomes the king of the hill.
Maintenance and Longevity
Let's be honest, racing is expensive. One of the reasons why people love burris 33a tires is that they actually last a decent amount of time if you take care of them. Unlike some ultra-soft qualifying tires that are "one and done," a well-maintained set of 33as can last you several race nights.
The key to longevity is cleaning and storage. After a night at the track, you shouldn't just throw your tires in the back of the truck and forget about them. Dirt and prep chemicals can continue to react with the rubber. Giving them a good wash with some simple degreaser and water, drying them off, and then wrapping them in plastic wrap (Saran wrap works wonders) helps keep the oils inside the rubber. This prevents them from "drying out" or getting that chalky white look, which is a sign the tire is losing its life.
If your tires do start to feel a bit hard after a few weeks, you can usually bring them back to life with a "reface." A quick spin on a tire lathe or a session with some sandpaper can take off that dead top layer and reveal fresh, grippy rubber underneath.
The Importance of Air Pressure
You can't talk about burris 33a tires without mentioning air pressure. In karting, air pressure is basically your "spring rate." Because karts don't have traditional suspension, the tires do all the work of absorbing bumps and controlling the weight transfer.
With the 33a compound, even a half-pound change in PSI can completely change how the kart handles. Generally, you'll see guys running anywhere from 4 PSI to 8 PSI depending on the corner of the kart and the track conditions. Lower pressure usually means more grip because the tire has a larger contact patch, but it also creates more "drag." If you go too low, the kart will feel slow on the straightaways. Higher pressure makes the kart "free up," allowing it to rotate better in the centers of the corners, but if you go too high, you'll just slide across the top of the track.
Why Consistency Trumps Everything
At the end of the day, the reason why burris 33a tires are so dominant isn't just about raw grip—it's about consistency. When you're mid-corner, door-to-door with someone at 40 mph, you need to know exactly what your tires are going to do. You don't want surprises.
The manufacturing process at Burris is legendary for its quality control. When you buy a 33a today and another one six months from now, you can trust that they're going to behave the same way. That's why so many tracks and racing series have made Burris their "spec" tire. It levels the playing field. When everyone is on the same rubber, it comes down to driver skill and who can tune their chassis and tire prep the best.
If you're just getting started in karting or if you're looking to step up your game, don't overthink it. Grab a set of burris 33a tires, learn how to read your durometer, and start experimenting with your prep. Once you find that "magic" setting, you'll understand why these tires are the gold standard for dirt track racing. It's a learning curve, for sure, but that's half the fun of being at the track. Keep them clean, keep them wrapped, and they'll treat you right on Saturday night.