Dirt Bike Tires & Wheels Explained - Sizes, Pressure, Treads & Tools

Most of us can't ride a factory-sponsored dirt bike like the pros do, so we're forced to pick and choose, save our money and upgrade as finances allow. But, if there is one thing you should never skimp on make it dirt bike tires.

Think about it - what keep you rolling along? Dirt bike tires can be the difference between smooth cornering, winning the holeshot, mastering the whoops and landing a jump. Uneven knobs, bad inflation and even the wrong compounds making up the tire all influence how your bike rides which affects the mechanics like working the engine harder than necessary or how the shocks respond to the terrain.

When in doubt grab a pair of the best tires available for your dirt bike and everything else will follow.

How to Know When you Need New Dirt Bike Tires

First things first - when is it time to get new dirt bike tires?

At first glance your dirt bike tires look ready to ride but after closer inspection those rubber hula hoops needed replacing a long time ago.

Check out the knobs. Once the knobs get rounded down or too short it's time for new tires. You may also notice some knobs completely chunked off leaving gaps of nothing on your tires - it's time for new tires!

Check out the tire rubber. If the rubber is dry, discolored or cracked - it's time for new tires. New tires look fresh with a deep dark black color. Old tires can also look weathered and should be replaced even if the knobs are intact and square. The shelf life of dirt bike tires is approximately four to five years after the manufacture date. (See below for information on the manufacture date.) If your tires are that old - it's time for new tires!

How to Choose the Right Dirt Bike Tires

Choosing the right dirt bike tire depends on your type of riding. Essentially, dirt bikers ride dual sport, motocross, or off-road/trail riding.

Dual Sport

Dual-sport riding is both off-road and street-legal riding as dirt bikes can be registered and licensed. Every now and then you may see someone on a dirt bike riding alongside your car. These dirt bikes have passed certain criteria to ride on regular public roads. See How to Make a Dirt Bike Street Legal.

These bikes feature street-legal equipment such as:

• Lights
• Speedometer
• Mirrors
• Horn
• License plate mounting
• Mufflers

Some tires models are geared towards street use and others towards off-road use. The tires used depend on how much riding is done on the street versus off-road.

Dual-Sport Tire Design & Pattern

If the street is merely a path to the great outdoors, dual sport tires look more like straight-up dirt bike tires. But if a rider uses their dirt bike for commuting purposes, the tires look like regular motorcycle tires. Sportier looking tires handle the road well and manage along dirt and gravel roads but can't be used for all-out racing in dirt.

 

Motocross/Supercross

Motocross is a man-made course on naturally occurring terrain and Supercross is a man-made course created from truckloads of dirt inside an arena or stadium. Both feature jumps and sharp turns but the type of soil used can vary.

Superficially, the tires used in each style of riding probably look quite similar but the soil composition determines what type of tire to use. Loamy, rocky, even sandy soil each requires a different set of tires constructed with different rubber compounds.

Motocross Tire Design & Pattern

 

Motocross tires bring the tread. These knobby type tires vary based on the type of track. Soft loamy dirt, sand and mud get a harder compound rubber tire composed of taller and wider-spaced knobs that create a paddle effect and keep mud from packing in between the knobs.

Firm terrain requires a softer rubber tire that conforms easier to the ground. Knobs are closer together and shorter to prevent flexing which creates a larger contact patch for better grip. In the middle you get intermediate tires - the most common selection. These tires tend to work well in most conditions.

See below for additional information on tire construction.

Off-road/Trail Riding/Enduro

Off-road trail riding varies from tight single track trails in the mountains, down to high speed wide open desert riding and everything in between. Off-road and trails throw naturally occurring obstacles at riders like boulders, tree trunks, mud, water and a various types of soil from compact and hard to the sand of the dunes.

Off-Road/Trail Tire Design & Pattern

 

Enduro Tires

Enduro riding has picked up in popularity and though similar to off-road riding involves taking your dirt bikes on long off-road courses that traverse a wide variety of terrain and obstacles like large boulders, water hazards and tight, winding pathways on hard and soft pack. These tires work better in mud than a trials tire while using the same rubber compound and offering better braking. Enduro riders need a completely different set of tires than any other type of dirt bike riding.

Enduro Tire Design/Pattern

Off-road tires are made for the off-roads! These tires provide a heavy duty framework for durability and vary as compared to motocross tires for knobby layout. In muddy and loamy trails a soft-terrain tire with wider and taller knobs is best. Trails exhibiting lots of rocks and a harder floor need a harder terrain tire with closely spaced and shorter knobs to improve traction.

Keep in mind that desert riding poses a challenge as terrain can vary from incredibly deep silt to a hard base and lots of rocks. Desert tires, similar to an intermediate motocross tire, address these varying terrains. Sand dune or paddle tires don't have knobs but instead features what looks like a series of paddles to push you along.

Generally, off-road tires look similar to Motocross tires and many riders pick a Motocross tire for off-road riding. But when tackling the world of enduro, you need an enduro specific tire to handle the diversity in terrain and hazards.

What Do All Those Numbers Mean?

Look along the rim of your tire. There's a whole mess of letters and numbers and you'd think only a CIA agent could crack the code. It's really not all that hard. Here's a diagram of a popular Bridgestone tire:

The codes vary, of course, from tire to tire but for the most part are universal across brands:

• M403 (model #)
• 80/100-21 (tire width/aspect ratio - rim diameter)
• 51M (Load and Speed Rating, 51 = tire load rating, M = tire speed rating)
• 2912 - This tire was manufactured the 29th week of 2012

Tire Construction: Does it Matter What the Tire is Made Out of?

A big wholehearted YES here. Different rubber compounds work best on one terrain over another.

A hard terrain tire is made of a softer compound to give you more grip on hard and slick surfaces, whereas a soft terrain tire is made of harder compounds so the tire can dig in more for traction. If you don't always know what terrain greets you on riding day or you typically end up riding both hard and soft terrain, grab a set of intermediate tires.

Intermediate tires represent the most popular choice among riders as it provides versatility to switch from one type of terrain to another. Keep in mind it is best to run the same rubber compounds on the front tire as you do the rear tire.

All tire manufacturers disclose what type of tire it is and we prominently feature what the tire is built for under the product description on our website. The tire itself doesn't say what it's best used for so if all else fails - just ask.

Proper Inflation

Proper tire inflation is the MOST important aspect to tire maintenance.

Tire pressure depends on riding conditions, terrain type and of course the type of tire you're riding. The best way to determine the proper tire inflation is to check the tire's service specs.

Generally, dirt bike tires run between 10 to 20 PSI. Again, check the service specs for proper running as each manufacturer's tire is different and requires different PSI depending on the terrain.

Improper tire pressure affects the following:

• Over/under inflation can lead to tube or tire failure
• Over/under inflation can cause irregular thread wear on the tires
• Over inflation lessens the tire contact area with the riding surface
• Over-inflation can cause the tire to wash out or slide around on top of the riding surface
• Under inflation may result in the tire not staying beaded on the wheel
• Under inflation affects the contact area and causes the tire to bow up in the middle leaving only the outer thread contacting the ground
• Under inflation can cause the tires to grab into the riding surface

As you can see, tire pressure can greatly affects handling characteristics so it is a good idea to always check your tire pressure every time you ride for proper PSI.

 

How to Store Your Dirt Bike Tires

The best environment for your tires when not in use is a cool, dark and dry area. High temperatures, varying temperatures, humidity and direct sunlight affect the rubber compounds and age the tire faster. Of course, tires should not be exposed to gas, oil or other corrosive chemicals that may be in your garage or shed.

Ideally, your bike should rest on a stand when not in use. This keeps excess weight off of one section of your tire and you don't have to worry about spills on the garage floor.

 

Break-in Period for New Dirt Bike Tires

There is not a break-in period per say, however you don't want to hit the throttle on a brand new set before you get the feel of the tires for your bike and the lay of the land. It's always a good idea to take it easy until you know how the tire responds to the terrain.

Dirt Bike Wheels

What good does a great pair of tires do if you don't have an equally great set of wheels? In many respects the tire and wheel act as one - go inferior on one but high-end on the other and you'll just drag yourself down. To get the most out of your tires you need to get some great wheels and vice versa as both affect how well the bike handles and the smoothness of the ride.

The wheels on a dirt bike differ in size from front and back but other than that have the same features. The front wheel typically runs bigger than the rear wheel which offers a more comfortable ride over rough terrain. You can get front dirt bike wheels between 18- and 21-inches. The rear wheel ranges between 17- and 19-inches. The small rear wheel maximizes the acceleration efforts of the dirt bike.

A dirt bike wheel consists of:

• Axle
• Wheel hub
• Wheel rim
• Spokes
• Nipples
• Bearings

Wheel construction typically consists of an aluminum or steel outer rim with steel spokes and nipples that connect to a center hub. The spokes give the wheel flexibility to handle bumps, ruts and those big jumps and hard landings. Therefore spoke maintenance is a high priority and something many riders tend to overlook.

Check spokes often and adjust when necessary. Loose spokes prevent the wheel from spinning straight and can damage the wheel and cause handling issues. Loose spokes also break or bend more easily, can puncture tubes and cause bent or broken wheels and hubs. Overly tight spokes can snap, damage the wheel, or strip out at the nipple and break the hub.

 

Spoke Wrench, Tubes, Rim Locks and Rim Strips

Did you think you were all set with just tires and wheels? A few additional items are necessary to ensure optimum operation of the tires and wheels.

Spoke Wrench

Remember all that talk about adjusting your spokes? Adjusting spoke tension is like checking the air pressure - you'll do it every time you ride. Using your fingers won't work. Get a spoke wrench to do the job right.  

Tubes

Just like a BMX or mountain bike you probably ride, your tires need tubes. Several options exist so we've narrowed it down to some of the better and more popular choices riding on today's dirt bikes.

 

Rim Locks

Rim locks keep the tire secure and prevent it from spinning on the rim when the bike is accelerating or braking. Most dirt bikes use one rim lock per wheel but some require two on the rear wheel. Size your rim locks according to the width of the rim.

 

Rim Strips

Rim strips keep the spoke nipples from puncturing the tube. Rim strips run on the inside of the tire along the tube to separate the tube from the nipples on the inside of the wheel. Yes, duct tape works as a cheap and dirty method but don't be surprised if your competition using real rim strips rides past as you tend to a flat tire.

 

Dirt Bike Tire Installation Tools

You didn't think we'd discuss dirt bike tires and wheels without mentioning the required installation tools, did you? Unless you have more than two arms and fingers made of steel the following tools should be in your tool box.

Tire Irons

Tire irons give you leverage (or that versatile third arm) so you can work the tire around the wheel and get it on without pinching your fingers and damaging the tire plus a whole lot less frustration. Tire irons come in the standard size and in a BIG size which some mechanics and do-it-yourselfers prefer.

   

Rim Protectors

Rim protectors help prevent the tire iron from damaging the wheel rim during tire changes.  

Bead Tool

The bead tool helps keep the bead (the edge of the tire that sits on the wheel) down and in place while you use other tire changing tools. Essentially, this handy little tool keeps your tire from popping off the rim as you try and work it around the wheel to get it in place.

 

Tire Changing Stands

Get off the floor! There's an easier way. Tire changing stands take the aggravation out of changing those tires. Change tires standing up at a level that is most comfortable for you. Save your knees and your back with a tire changing stand.

 

Tire/Air Pump

So now you're all set. You've successfully put together a new set of tires and wheels for your dirt bike and it's time to ride. Except there's one last thing needed before you head to the track. You need air in those tires! Skip the trip to the gas station and fill those tires with air in your garage. You likely already have some type of air pump if you have mountain bikes or kids with bikes but if you don't or looking to upgrade we've got several options to consider.