This month in “Tires 102,” we sat down with Brian Fleck from Dunlop Tires. Brian has been at the core of Dunlop’s tire development for motocross and off-road race teams for over 35 years. We tapped into his expertise to answer some of the most commonly asked questions about tires.

Dirt Bike: How do I choose the right rear tire for me? There are so many tread pattern choices specific to different terrains, it’s confusing.

Brian Fleck: Off-road riding offers a wide range of terrain, so there are more tire choices. For slower, tighter trails on the East Coast and Midwest, an intermediate tire is the best option. These areas feature diverse terrain and varying amounts of moisture. Good choices for these trails and races include the AT81 or the MX33/MX34 intermediate to soft tires. For faster events on the West Coast, we recommend hard-terrain or desert-type off-road tires such as the AT81 RC, D908RR, or MX53. These tires have larger blocks and offer better durability compared to intermediate/soft-terrain tires. The choice of front tire for these races depends on the amount of sand on the trail. Most riders prefer an intermediate front tire. For pure motocross tracks, we use intermediate to soft tires in about 85% of the cases.

Dirt Bike: For enduro riding, which is more important – high wear or high grip?

Brian Fleck: It depends on the rider’s priorities. If achieving race results is the main goal, then grip is crucial. For technical and rocky terrain, the best option is the EX series tires. Dunlop offers two options – the Enduro EN91 EX for softer terrain and the AT81 EX with tighter knob spacing. Both feature super-soft rubber for enhanced traction. You can manage wear by not being too aggressive with the throttle. Many trail riders are using EX tires because they make riding difficult terrain easier.

Dirt Bike: I’m on a budget and I want a tire that provides the best traction and durability. Is there a tire that can do it all?

Brian Fleck: It’s always a challenge to find a tire that balances performance and durability. Usually, a hard-terrain tire like the MX53 works well and offers better durability than intermediate to soft tires. If a tire shows little to no wear, it’s usually an indicator that it doesn’t provide the best performance. Tires wear when they offer good grip.

Dirt Bike: How do I choose the right rear tire size? Is a taller sidewall or a bigger contact patch better, and where should it be used?

Brian Fleck: In soft and rutted conditions, a smaller and narrower tire size is sometimes a better choice. The narrower tire doesn’t get caught on the edges of the ruts as much. In Supercross, many 450 riders use a 110/90 rear tire because the whoops develop cupping and have many edges that grab the tire. When the tracks are drier and not as rutted, a wider rear tire works better on the 450 bikes during acceleration and braking. The 120/80 size is firmer than the 120/90, and the 90 provides a plusher sidewall. The 90 also has a longer footprint, which improves start grip and performance.

Dirt Bike: In off-road riding, fatty fronts are popular. Why are they better or worse in certain situations?

Brian Fleck: Fatty front tires have a larger carcass, which absorbs impacts from rocks and roots better. They are also great for terrain that requires maximum traction, like EX-type conditions. The downside is that fatty front tires can result in heavier steering and reduced responsiveness in tight terrain. Many riders find that full-mousse inserts don’t perform as well with bigger front tires.

Dirt Bike: In off-road riding, should I run super-thick tubes to prevent flats?

Brian Fleck: Super-thick tubes are a good choice for off-road riding. They provide a better feel compared to full-mousse inserts, which can make the ride feel dead or unresponsive. Interestingly, many top off-road racers prefer the dead feeling of a mousse insert, especially in rocky terrain.

Dirt Bike: Do dirt bike wheels need to be balanced after installing new tires?

Brian Fleck: Balancing the wheels would be beneficial for high-speed off-road races, but not as necessary for motocross.

Dirt Bike: What is better, thick tubes or mousse inserts?

Brian Fleck: It depends on the rider’s preferences. Most riders prefer the rebound and absorption provided by inner tubes. Full-mousse inserts are heavier and give a dead or unresponsive feel. However, they do allow riders to attack challenging terrain without worrying about flats. There is a learning curve both in terms of riding and installing mousse inserts.

Dirt Bike: How do I pick the right front tire? I ride motocross, off-road, and some desert. Is there a tire that can handle all of it?

Brian Fleck: Choosing the right front tire is a personal preference. It’s a good idea to try several options to find the tire that offers the best traction and steering characteristics for your riding style. Starting with an intermediate front tire is a good baseline. Professional riders often have more front tire choices than rear tire choices. Once they find a front tire they prefer, they use it for all types of riding.

Dirt Bike: How often should you change your front tire? It seems to last much longer than the rear tire.

Brian Fleck: Front tires don’t wear as quickly as rear tires. You need to check how much the sidewall starts rolling as you put more hours on the tire. The carcass starts breaking down even if the knobs show minimal wear. Check your rim after riding to see how much the tire is rolling over the edge. Some riders increase front tire pressure to compensate for the softer carcass.

Dirt Bike: Are all tires directional? How important is this?

Brian Fleck: Whether a tire is directional or not depends on the pattern and design. Most soft-terrain tires, like the MX14, are directional. The pattern is designed to dig into the terrain better in one direction.