Dirt Bike Tire Size Chart | Motocross & Off-Road Tire Sizing Guide

Dirt Bike Tire Size Chart

Use this motocross and off-road tire sizing chart to compare common front and rear tire sizes for popular dirt bike classes. Tire sizing can vary by year, model, wheel size, and previous modifications, so always verify the size printed on your current tire or check your owner’s manual before ordering.

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How to Read Tire Sizes

A size like 80/100-21 means the tire is about 80 mm wide, has a sidewall height that is 100% of the width, and fits a 21-inch rim.

Front vs. Rear Tires

Front tires are usually narrower and designed for steering feel. Rear tires are wider and built for traction, drive, braking, and durability.

Check Before Ordering

For the safest fit, confirm your current tire size, wheel size, and bike model. Some bikes may use different sizes depending on year or setup.

Fitment note: This chart is for general reference only. Always verify your tire size before purchasing. If you are unsure, contact MX Parts Direct with your bike’s year, make, and model.

Common Motocross & Off-Road Tire Sizes

Use the chart below as a quick reference for common youth, mini, and full-size dirt bike tire sizes.

Bike / Class
Common Front Size
Common Rear Size
Popular Front Option
Popular Rear Option
Quick Notes
Yamaha PW50
2.50-10
2.50-10
60/100-10
70/100-10
Small youth bike. Verify clearance before upsizing.
KTM 50SX Mini
2.50-10
2.50-10
60/100-10
70/100-10
Mini 50cc setup with 10-inch wheels.
KTM 50SX
2.50-12
2.50-10
60/100-12
70/100-10
Common 50cc race setup with larger front wheel.
110cc Pit Bikes
Kawasaki KLX110 / Yamaha TT-R110
2.50-14
3.00-12
60/100-14
80/100-12
Common KLX110 and TT-R110 setup. Verify if the bike has aftermarket wheels or pit bike upgrades.
65cc Bikes
KTM / Husqvarna / GasGas / Kawasaki
60/100-14
80/100-12
—
—
Common 65cc race bike tire sizing.
85cc Small Wheel
17/14 wheel setup
70/100-17
90/100-14
—
—
Common small-wheel 85cc size.
85cc Big Wheel
19/16 wheel setup
70/100-19
90/100-16
—
—
Common big-wheel 85cc size.
125cc / 150cc
80/100-21
100/90-19
90/100-21
110/90-19
Some riders choose a slightly wider setup for extra stability and traction.
250cc 4-Stroke
80/100-21
100/90-19
90/100-21
110/90-19
Popular MX setup for 250F bikes.
250cc 2-Stroke
80/100-21
110/90-19
90/100-21
120/80-19
Wider rear options are common depending on terrain and rider preference.
450cc
80/100-21
110/90-19 older / 120/80-19 newer
90/100-21
120/80-19
Many modern 450 motocross bikes use a 120/80-19 rear tire.

Ready to Find the Right Tire?

Choose a trusted tire brand below, or shop tubes if you are replacing a tire and want a fresh tube at the same time.

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Dirt Bike Tire Size FAQ

Can I run a different tire size than stock?

Sometimes, but it depends on your bike, wheel size, swingarm clearance, riding style, and terrain. A slightly wider rear tire may improve traction, but it can also affect handling and clearance. When in doubt, stay with the stock size or ask for fitment help.

What is the most common front dirt bike tire size?

Many full-size motocross and off-road bikes use a 21-inch front tire, commonly in sizes like 80/100-21 or 90/100-21.

Should I replace the tube when replacing a dirt bike tire?

It is a good idea to inspect or replace the tube when installing a new tire, especially if the tube is old, patched, pinched, or has been used through multiple tire changes.

What tire should I choose for soft terrain?

Soft-terrain tires are designed for sand, loam, and mud. Intermediate tires are a good all-around choice, while hard-terrain tires work better on blue-groove, dry, or packed surfaces.