The majority of content written on the side of a dirt bike tire is to help identify the size, model and terrain the tire is suited to. The first series of numbers you will need to learn are the ones which relate to sizing followed closely by the tread pattern the tire is suited to.

How to choose the right size motocross tire:

The sequence of numbers which give you the tire sizing is set to give you first the tire width, then the tire wall height and finally the circumference of the rim the tire will fit onto. (See example below)

• 110/90-19

The “110” refers to the width of the tire in millimeters as does the “90” which refers to the wall height as a percentage of the width of the tire. The “19” refers to the circumference of the rim which the tire suits in an inch measurement. (Some variations of this are listed below)

• 100/90-19

• 130/90-18

• 80/90-21

• 120/90-19

Standard Dirt Bike tire Sizes

The majority of full-sized dirt bikes in the world run a 21” front tire and most motocross bikes run a 19” rear. Trail bikes vary with many running an 18” on the rear to suit the different types of terrain covered in enduro.

An 18” wheel typically has a taller wall height, the taller the tire wall means the more the tire can flex and roll which lowers performance through corners. Contrary to this the added flex gives a smoother, more controlled ride over tree roots and rocks which you encounter more on enduro.

Wider tires make the bike harder to turn, the wider the footprint the more it will want to stay upright which can cause a “front end push” feeling through turns. Also for soft terrain or rutted tracks, a wider tire will struggle to fit into ruts easily which will affect your performance.

A wide tire comes into its own on hardpack dry conditions, a wider footprint means more grip providing the tread pattern and tire rubber compound is suited.

No matter what bike you have it should have the wheel sizing written on its tires to identify what you have. Then its a matter of narrow down the tire you need by thinking about what type of terrain you ride on most.

It is important to choose the right sized tire recommended for your particular bike. If you decide to run a wider than the normal tire on a narrow rim the performance of the tire will be compromised as the shape of the tire carcass will have been changed as it is manipulated to fit onto the odd size of the rim. The same applies if you put a narrow tire on a wide rim it will push the tire wall out and change the tires’ footprint which will affect performance and grip!

How to choose the right tread pattern of motocross tire:

Different tires suit different conditions, hard terrain tires require more knobs with a larger, shorter block close together to increase the footprint which gives you grip. Soft terrain requires fewer knobs with a smaller, taller block which are spaced further apart to allow the tire to dig into the soft terrain giving you more grip.

Harder rubber compounds suit soft terrain surfaces while softer rubber compounds suit harder surfaces.

Similar to muddy conditions the added advantage of larger spacing between the knobs allows the tire to self clean easier. As the tire spins the mud collected will fling off so the clean knobs bite into more terrain every revolution.

But with the varying nature of dirt bike riding means you will usually encounter an array of different terrain, so unless you have a factory race teams’ budget for tires you will more than likely need to settle for an intermediate which will handle most things you can throw at it.

Have a good think about the terrain you are riding on most as with an intermediate tire there will always be a compromise in performance in one terrain compared to another so choose wisely!

How often should you replace your motocross tires:

Like anything tires have a finite lifespan, the shelf life of a   is around 4 years from manufacture but if you are riding regularly this will be much quicker!

You can check your tires by simply looking at them if the knobs are rounded down or short they aren’t going to perform very well. Knobs can actually crack and become ripped off completely so if you are missing any knobs you are up for a new set of tires.

If you ride frequently this will occur quickly but if you only ride on the odd occasion (poor you) you will need to keep an eye on the health of the rubber. Over time the rubber will become dry, cracked or discolored. New tires have a very dark which fades out to a grey with age, the older the tire the harder and more brittle the rubber becomes which will affect performance.

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.

The most important point of tire maintenance is tire pressure:

The correct pressure to inflate your dirt bike tubes to will vary from track to track but the majority of dirt bike tires run between 10-20psi. If you aren’t sure you can check your owner’s manual, the harder you inflate your tire the less grip you will have. If your tire is too soft it will give a very spongy feel and roll more on the rim through corners affecting your performance.

Inflating your tires to around 16psi tends to be a popular choice but again, check your owner’s manual and if you are at a track don’t be scared to ask other riders. You should check your tire pressures before every time you throw your leg over your bike as they can vary a lot every hour and this will affect your performance a great deal!

Other issues you can encounter with incorrect tire pressures are:

• Tube or tire failure, punctures

• Cause uneven tire wear

• Under-inflation can cause the tire to come off the bead

Do the new motocross tires have a break in period:

There is no break-in period for new motocross tires, however, we do suggest to ease into riding on a fresh set of rubber particularly if you have changed size, tread, brand or rubber compound. Get a feel for your new shoes to work out how well they hang on before you go full throttle into a corner or you may end up on the ground before you have even worked up a sweat!

CHECK OUT THE MASSIVE RANGE OF DIRT BIKE TYRES AT MXSTORE:

• Bridgestone Dirt Bike Tyres
• Dunlop Dirt Bike Tyres
• IRC Dirt Bike Tyres
• Michelin Dirt Bike Tyres
• Motoz Dirt Bike Tyres
• Pirelli Dirt Bike Tyres

If you have any further questions regarding tyre selection don’t hesitate to contact the friendly MXstore team

Source: MXStore.

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