How to Choose the Right Size for Dirt Bike Gear

Tips for Choosing the Right Size Motocross Gear

When it comes to dirt biking, the right gear doesn’t just protect you, it allows you to ride with confidence. But even the best gear can fail you if it doesn’t fit correctly. A helmet that shifts during a fall, boots that pinch your feet, or pants that restrict movement can all lead to discomfort at best, and injury at worst.

Sizing motocross gear isn’t as straightforward as picking your usual jeans or t-shirt size. Unlike streetwear, dirt bike gear needs to account for impact protection, body positioning, and layering with armor or braces. Each brand uses its own sizing guidelines, which means guessing or winging it isn’t an option.

In this guide, we’ll break down how to size every major piece of dirt bike gear; helmets, jerseys, pants, gloves, boots, and more. Using proven measurement methods and real-world fitting advice. You’ll also learn what to avoid, how to account for youth sizing, and why the “tight vs loose” debate matters more than you might think.

Whether you’re a first-time rider or just upgrading your setup, getting the right fit is the first step toward a safer, more enjoyable ride. Let’s get it right, head to toe.

General Sizing Principles

Before diving into sizing individual pieces of gear, it’s important to understand the fundamentals of how motocross gear should fit. Proper sizing isn’t just about comfort, it’s essential for safety. Gear that’s too loose can shift or slide during a crash, while gear that’s too tight can restrict movement or cause pressure points that distract you on the bike.

1. Always Measure, Don’t Guess

Use a flexible, soft measuring tape to take your own measurements. Don’t rely on your standard clothing size or age-based sizing, those don’t account for the unique fit and function of protective gear. Measure areas like your head, chest, waist, hands, and inseam, and write them down so you can cross-reference multiple size charts.

2. Reference Brand-Specific Size Charts

Each gear manufacturer uses its own sizing standards, so a size 32 pant from one brand may fit differently than the same size from another. Always refer to the most up-to-date sizing chart provided by the brand, and check for any specific notes on fit (e.g., “runs small” or “designed for use with knee braces”).

3. Factor in Protective Equipment

Jerseys and pants often need to accommodate body armor, chest protectors, and knee braces. If you plan to wear a pressure suit or extensive under-gear protection, consider sizing up accordingly. The goal is to layer protection without restricting movement or circulation.

4. Aim for Snug but Mobile

Properly fitted gear should feel snug, but not tight. You should be able to move freely; stand, sit, grip the bars, and bend your knees, without the gear bunching, pinching, or sliding around. If it’s restrictive or constantly needs adjusting, it’s likely the wrong size.

5. Try It On with Full Gear

Whenever possible, try on gear while wearing all the protective equipment you’ll use while riding. Sizing gear in isolation (for example, pants without braces or boots without socks) can result in misjudging the actual fit and feel once you’re fully suited up.

Getting these basics right ensures a more accurate fit across every gear category and sets you up for safer, smoother rides. Now, let’s break it down piece by piece.

How to Size Each Piece of Gear

Every piece of dirt bike gear serves a specific purpose, and each one needs to fit properly to work as intended. Below is a breakdown of how to measure for each item, how it should fit, and what to keep in mind when sizing up or down.

Helmet

How to Measure Helmets Sizing:

Wrap a soft measuring tape around the fullest part of your head, about a half-inch above your eyebrows and ears, circling around the widest point at the back.

Fit:

The helmet should fit snugly against your entire head without creating pressure points. It should stay in place when you shake your head, but not feel painfully tight. There should be no room to slide fingers between your head and the liner.

Pro Tip:

Don’t size up expecting a break-in. Foam will compress slightly with wear, but sizing up can lead to dangerous movement in a crash.

Jersey

How to Measure Jerseys:

Measure your chest at its fullest point, usually 1 inch below the armpits and across the widest part of the chest, keeping the tape level across the back.

Fit:

A dirt bike jersey should be loose enough to allow airflow and movement but not so oversized that it catches on branches or flaps excessively. If you wear body armor underneath, consider going up one or two sizes.

Pro Tip:

Most jersey sizes coordinate with pants (e.g., if you wear size 32 pants, a Medium jersey usually fits).

Pants

How to Measure Pants Sizing:

Measure your waist where you’d naturally wear pants while riding (usually lower than your normal jeans). Also measure your inseam from crotch to ankle.

Fit:

Pants should feel secure at the waist without cutting in, and roomy enough through the thighs and knees to accommodate knee braces or guards. Mobility in a seated or crouched position is critical.

Pro Tip:

Stick with your regular jeans size as a starting point, but double-check with each brand’s chart some run smaller than others.

Gloves

How to Measure Those Gloves:

Measure the circumference of your dominant hand, just below the knuckles (excluding the thumb), with your hand slightly cupped.

Fit:

Gloves should fit close to the skin to prevent bunching and maintain grip. Too tight, and they’ll restrict movement; too loose, and you risk blisters and loss of control.

Pro Tip:

If you’re between sizes, size down gloves tend to stretch slightly after use.

Boots

How to Measure Boots:

Measure the length of your foot from heel to the tip of your big toe, ideally in centimeters. Use this to match against the brand’s boot sizing chart.

Fit:

Boots should fit like a firm handshake secure around the heel and ankle, with enough room for thick socks but not so much that your foot moves. You should feel supported, not squished.

Pro Tip:

Some boots (like Gaerne or Alpinestars) run large or small always consult the brand-specific chart.

Knee Guards / Braces

How to Measure Knee Protection:

Follow the manufacturer’s instructions some require measurements above, below, or directly around the kneecap.

Fit:

Knee protection should stay in place without pinching or sliding. Straps should be snug but not so tight they restrict circulation or dig into the skin.

Pro Tip:

Try guards or braces on with your riding pants to ensure compatibility some combinations don’t play well together.

With the right measurements and fit in place, your gear will do its job: keep you safe, comfortable, and ready to ride with confidence. Up next how to get it right when buying youth gear.

Youth Gear Sizing

When it comes to youth dirt bike gear, getting the right size is even more critical and often more confusing. While many brands label youth gear by age, this system can be misleading. Kids grow at different rates, and sizing by age alone rarely delivers the fit needed for both safety and comfort.

Measure, Don’t Rely on Age Labels

Skip the guesswork. Use a soft measuring tape to take accurate measurements of your child’s:

• Head circumference (for helmets)
  

• Chest (for jerseys and body armor)
  

• Waist and inseam (for pants)
  

• Hand circumference (for gloves)
  

• Foot length in centimeters (for boots)
  
  

Compare these numbers to youth-specific size charts from the gear manufacturer. Even within the same brand, sizing can vary between product lines, so double-check each chart individually.

Fit for Protection, Not Growth

It’s tempting to size up so your child “can grow into it” but oversized gear shifts during a crash, reducing its protective capabilities. Helmets that wobble, boots that allow foot movement, and jerseys that ride up can all compromise safety. Choose gear that fits now, and replace it as needed.

Try Full Kits Together When Possible

If your child will be wearing chest protectors, knee guards, or neck braces, try everything on at once. A jersey that fits solo may feel restrictive once armor is added. Pants that seem fine on their own may not fit over knee protection. Testing gear in combination helps avoid surprises on ride day.

Look for Adjustable Features

Many youth gear items come with Velcro straps, ratcheting buckles, and elastic panels that offer room for minor growth without sacrificing fit. Prioritize these features, especially for boots, gloves, and body armor.

Consult Brand Guides

Top gear brands like Fox Racing, Fly Racing, Alpinestars, and Troy Lee Designs offer youth-specific sizing charts. Use them, and don’t hesitate to reach out to customer service if you’re between sizes or unsure.

Youth riders deserve the same level of protection and comfort as adults and that starts with dialing in the right size. Up next: common sizing mistakes and how to avoid them.

Common Sizing Mistakes to Avoid

Even with the best intentions, it’s easy to make sizing mistakes that compromise protection, comfort, or both. Here are the most common pitfalls and how to avoid them.

1. Guessing Based on Streetwear Sizes

Dirt bike gear is built for impact, ventilation, and riding posture it doesn’t follow the same sizing logic as your jeans or hoodie. Don’t assume a Medium in casual clothing equals a Medium jersey or helmet. Always measure and check the size chart.

2. Oversizing for “Growing Room”

This is especially common with youth gear. While the idea of buying big to extend use might seem practical, oversized gear can shift, bunch, or even come off during a crash. This defeats the purpose of wearing protection in the first place.

Rule of thumb: fit for now, not for later. Gear that’s too small can be uncomfortable but gear that’s too big can be dangerous.

3. Ignoring Brand-Specific Size Charts

Sizing varies significantly between manufacturers. A size 32 pant from one brand may fit like a 30 or a 34 in another. Always consult each brand’s most recent chart, and don’t rely on third-party charts unless they’re confirmed to be up to date.

4. Forgetting to Account for Body Armor

Many riders size their jerseys or pants without considering added bulk from chest protectors, pressure suits, or knee braces. If you’re planning to wear gear underneath, adjust your sizing accordingly or try it all on at once to get the right fit.

5. Expecting a “Break-In” to Solve Fit Issues

Some gear (like boots or gloves) will soften slightly over time, but a poor fit won’t magically improve with wear. If something is uncomfortably tight out of the box or causes pressure points, it’s probably the wrong size.

6. Skipping the Movement Test

You’re not just standing in this gear, you’re riding. Always test gear in a simulated riding position: crouch, squat, extend your arms, grip handlebars, and twist at the waist. If anything binds, rides up, or shifts awkwardly, reassess the sizing.

Avoiding these mistakes will save you money, prevent frustration, and most importantly help keep you protected on every ride. Up next: final tips to make sure your gear fits like it should.

Final Fitting Tips

Once you’ve measured, consulted size charts, and narrowed down your gear choices, a few final steps can make all the difference in getting that dialed-in fit. These tips apply whether you’re buying online or trying gear on in person.

1. Try It On With All Your Gear

Never assess one piece of gear in isolation. A jersey might fit great on its own, but feel tight or restrictive once a chest protector or pressure suit is added. Pants that seem roomy might feel tight once knee braces are strapped on. Always try gear on in full riding form, with everything you’ll be wearing on the bike.

2. Use the Riding Position Test

Once suited up, assume your typical riding position. Crouch slightly, sit down as if on your bike, reach forward like you’re grabbing handlebars. This exposes issues you won’t notice standing upright like tightness behind the knees, a gaping collar, or pants sliding down at the waist.

3. Watch for Pressure Points and Gaps

A good fit means protection stays in place and doesn’t cause discomfort. Helmets should feel evenly snug without hot spots. Gloves shouldn’t cut circulation. Boots should support your ankles without pinching. Gaps in protection especially at the wrists, knees, and lower back often signal poor sizing or layering issues.

4. Don’t Rely on Breaking It In

Yes, some gear breaks in slightly over time especially leather boots and gloves but if something feels too tight or wrong on day one, it likely won’t improve. Prioritize fit right out of the box.

5. When in Doubt, Ask

If you’re between sizes, unsure about fit, or comparing brands, contact the manufacturer’s customer support or ask the retailer for a recommendation. You can also check rider forums and YouTube reviews real-world feedback often highlights sizing quirks not listed on a chart.

Getting the right fit isn’t about luck it’s about preparation. When your gear fits properly, you ride better, safer, and with more focus. Up next: trusted resources to help you size, shop, and stay informed.

Recommended Resources

Sizing dirt bike gear correctly takes more than a guess and a glance it takes precise measurements and reliable reference points. Below are some of the most helpful resources for making smart, accurate sizing decisions, whether you’re buying gear for yourself or a young rider.

1. Sizing Charts and Brand Guides

• BTO Sports Size Charts
  
  

2. Video Guides and Reviews

• How to Size Motocross Helmets
  
  A helpful visual for new riders trying to figure out helmet fit and adjustment.
  
  

• MX Gear Sizing: General Guide
  
  Easy-to-follow breakdown of how gear is meant to fit, with sizing rules of thumb.
  
  

3. Community Feedback & Forums

• Reddit: r/Dirtbikes – Gear Sizing Discussions
  
   Real-world sizing feedback from other riders especially helpful when comparing brands or sizing inconsistencies.
  

Using these resources will help you make better gear choices, avoid sizing surprises, and ensure your protective equipment performs as intended. Don’t just buy; measure, compare, and ride with confidence.

Conclusion

Choosing the right size for your dirt bike gear isn’t just a detail, it’s a foundational part of riding safely and confidently. Ill-fitting gear can compromise protection, limit mobility, and turn a great day on the bike into an uncomfortable or even dangerous experience.

By taking the time to measure accurately, consulting brand-specific sizing charts, and trying gear on with your full kit, you’re not only protecting yourself, you’re setting yourself up for a better ride. The same holds true for youth riders, where proper fit matters just as much, if not more.

Remember: fit first, function always. Whether you’re investing in your first set of gear or replacing a worn-out favorite, prioritize the right size every time. It’s the simplest way to boost your comfort, confidence, and safety out on the trail or track.