The best dirt bike helmets for trail riding share three things: rotational impact protection such as MIPS, a light shell that will not wreck your neck over a four-hour day, and a vent matrix that moves enough air to keep sweat out of your eyes. Get all three and the rest is fit.
Trail riding asks something different of a helmet than motocross does. A track session is short, loud and fast. A trail day is slow, technical and long, and most of your crashes are low-speed tip-overs or glancing handlebar hits off a rock. Heat and neck fatigue hurt you far more often than a high-energy impact.
We compared 12 dirt bike helmets for trail riding across certification, shell material, listed weight, vent count and fit adjustability. Four carry a named slip-plane system and one more uses a multi-density EPS liner. Our dirt bike gear guide for beginners covers the rest of the kit. Last reviewed in 2026.
Top 3 Best Dirt Bike Helmets for Trail Riding (October 2026)
ILM 128S Full Face Helmet
- DOT FMVSS 218 certified
- ABS shell with vented EPS liner
- Detachable washable inner pads
Oneal Sierra Helmet
- DOT FMVSS 218 and ECE 22.05
- Polycarbonate and ABS shell
- Drop-down sun shield
The short version: the ILM 128S is the one we would wear first, because of its venting, washable liner and the largest review base here. The Oneal Sierra adds a drop-down sun shield and a second certification standard for riders who cover pavement to reach the trailhead. The GLX GX23 has more vents than anything else on this list.
All 12 Dirt Bike Helmets Compared Side by Side
| Product | Specifications | Action |
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| ILM 128S Adult Full Face Helmet |
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| Oneal Sierra Helmet |
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| GLX GX23 Full Face Helmet |
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 ILM 606V Dual Sport Helmet |
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 OUMURS Adult Helmet Kit |
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 Bell MX-9 MIPS Helmet |
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 OUMURS Youth Dirt Bike Helmet |
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 Giro Radix MIPS Helmet |
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 Fox Racing V Core MIPS Helmet |
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 Orthrus Dual Sport Adventure Helmet |
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 Fox Racing V1 Motocross Helmet |
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 Alpinestars SM3 Off Road Helmet |
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1. ILM 128S Adult Full Face Helmet – The All-Rounder We Would Buy First
- Largest review base on this list
- DOT FMVSS 218 certified with a thick vented EPS liner
- Detachable washable inner pads
- Detachable visor for goggle days
- No MIPS or other rotational protection
- Fit runs narrow between sizes
- Visor hardware can loosen over time
The ILM 128S is the helmet we keep coming back to. It carries the largest review base in the roundup, and that matters, because a big sample is the closest thing to an independent test rig that off-road riders actually have.
Owners describe a comfortable shell with a solid vented liner and padding that pops straight out. The front and back vents do real work, and the visor detaches on goggle days, which trims weight and stops it catching branches.
Technically it is plain. ABS over expanded polystyrene, a buckle closure, no slip plane, no spherical shell. For slow rock strikes and tip-overs at walking pace, the thick vented EPS does most of the work. The listed weight of 1.88 kg is mid-table here, and reviewers flag the fit running narrow between sizes.
Is the ILM 128S good enough for long trail days?
Yes, as a first or only helmet. The removable washable pads decide it for us over a season, because a helmet you will not wash in August is a helmet you will not wear in August. Riders on a VitalMX thread split hard on whether a slip plane is worth paying for, and the honest conclusion there is that no independent comparison data exists.
Who should skip the ILM 128S?
Skip it for hard enduro or fast enduro racing, where angled high-energy impacts are the realistic failure mode; the Bell MX-9 MIPS or Fox V Core MIPS will suit you better. Skip it if your head is a long oval, because this is a generic single shell and elongated-oval owners report forehead pressure.
2. Oneal Sierra Helmet – The Best Value Pick for Trail Riders
- Dual certification to DOT FMVSS 218 and ECE 22.05
- Integral drop-down sun shield with adjustable peak
- Double-D ring retention
- Internal and external vent controls
- Listed weight of 2200 g is among the heaviest
- Fit runs small between MD and LG
- Awkward D-ring routing and loud at speed
The Oneal Sierra is the pick if your trailhead is half an hour of pavement away. The integrated drop-down shield is the feature that sets it apart on this list, and on a mixed loop it saves you carrying a second visor or swapping to glasses. Ventilation is controlled from inside and outside the shell, and owners single out the wide eyeport, which works with prescription glasses.
The double-D ring is the secure choice on technical terrain, where a buckle can pop open in a hard fall. It is also the most complained-about part, with the strap riding into the comfort liner and rings that are hard to find with gloves on.
Why the Oneal Sierra beats the cheaper budget helmets
The polycarbonate and ABS shell is a step up in stiffness from all-ABS designs, which matters when you land off a rock. So is the hardware: adjustable peak, dual-standard certification, internal vent controls.
Who should skip the Oneal Sierra?
Riders on technical terrain should test the D-rings with gloves on first, and anyone sensitive to wind noise will find it loud, which is expected from an open shell. At 2200 g it is one of the heavier entries, so full-day single-track pushes you toward a lighter pick. And it runs small: treat the MD-to-LG boundary as a coin flip.
3. GLX GX23 Full Face Helmet – The Ventilation Champion of the Budget Tier
GLX GX23 Full-Face Dirt Bike Motocross Motorcycle Helmet, DOT
- Sixteen vents
- the highest count here
- Multi-density EPS liner designed to reduce rotational forces
- Wind tunnel developed vent ports
- Helmet bag and spare visor hardware included
- Visor screws reported missing on some units
- Runs small and needs a break-in period
- Can run warm on the hottest days
The GLX GX23 carries a 4.7 average across more than 2200 reviews, and the reason is not subtle: sixteen vents and a wind-tunnel shaped intake layout. On a hot climb with a pack on your back, that airflow separates a helmet you tolerate from one you look forward to wearing. Owners also like that it is lighter and less bulky than expected for the class, at 3.2 pounds.
The multi-density EPS liner is listed as designed to reduce rotational forces. That is not a MIPS slip plane, and we will not pretend otherwise. It places firmer and softer foam in different regions, which can help manage angled loading without letting the helmet slide relative to your skull. The moulded shell carries FMVSS No 218 certification and a one-year limited warranty.
Is sixteen vents enough to solve trail heat?
For most riders, yes. Vent size and placement matter as much as the count, but the GX23 pairs the highest count here with a wind tunnel developed port layout. Owners report that the airflow also keeps the visor from fogging in humid conditions. On a peak desert afternoon it will still run warm, because a full shell always will.
What are the drawbacks of the GLX GX23?
Sizing is the main one: it runs small between sizes and needs a break-in period, so measure rather than guess. There are also isolated reports of missing visor screws arriving in the box. Check the hardware before the first ride, because a loose or missing screw is exactly the failure a breakaway design exists to prevent.
4. ILM 606V Dual Sport Helmet – Best for Riders Who Split Time Between Road and Trail
ILM DOT Motorcycle Dual Sport Dirt Bike Full Face Helmet ATV Men Women 606V
- Works as a rally
- full face or off-road helmet
- HD wide-angle lens with an internal tinted drop-down sun visor
- Quick release strap works with gloves
- Removable washable top liner and ear pads
- Clear visor fogs once you heat up
- Only three vents
- Runs slightly small and wind noise is high
If your riding involves a road section, the ILM 606V solves a problem the rest of this list struggles with. It is a genuine dual-sport design with a clear outer shield, an internal tinted drop-down sun visor, and enough sealing to run behind a windscreen without the buffeting a bare MX shell produces.
At 1.71 kg it is one of the lighter helmets here. The quick release strap is a real trail advantage, since you can put it on and take it off with gloves on. Owners regularly compare it favourably to dual-sport models costing considerably more.
On pure trail terrain it is the wrong shape of helmet. Three vents and a street-oriented shell mean you give up the airflow that makes a long single-track day bearable, and the most common complaint across more than 2200 reviews is visor fogging once you heat up unless the shield is left slightly ajar. Run an anti-fog insert and drop the visor at low speed.
Is a dual-sport helmet a compromise for trail riding?
It is, and the compromise is vents. You gain eye protection, a sun visor and a quiet highway ride. You lose the high-airflow shell trail riders prioritise. If your loop is 90 percent single-track, a pure off-road design is the better tool. If your gear stays in the car all weekend, buying one helmet instead of two becomes the stronger argument.
Should a glasses-wearing rider pick this one?
Probably. The visor drops and raises independently, so you ride with your glasses in the eyeport instead of juggling two shields, and it carries a two-year warranty. Watch the sizing though: it runs slightly small, and the hook-and-loop closure is a step down in security from a buckle or D-ring when you are wearing an earpiece.
5. OUMURS Adult Helmet Kit – The Budget All-in-One
OUMURS Full Face Dirt Bike Helmet DOT Approved, Adult ATV Motocross Helmet
- Helmet goggles gloves and mask in one box
- Light at a listed 1180 g for an adult shell
- Four adult size ranges with published measurements
- Double D-ring retention system
- Round head shape does not suit elongated oval heads
- Included goggles and gloves are considered basic
- Only two vents and a 60 day warranty
The OUMURS kit exists for a specific person: a new rider who needs a helmet, goggles, gloves and a mask this month and would otherwise buy all four separately. It is the lowest-cost route to being properly equipped, and at a listed 1180 g it is one of the lighter adult shells here.
The sizing detail is better than most brands a tier above. Four adult ranges from 570mm to 630mm with published millimetre measurements, plus a double D-ring rather than a soft strap. For a first purchase, real head circumference ranges are worth more than any shell spec.
What you give up is refinement. ABS shell, EPS lining, a shape listed as round, only two vents, and gaps in the size chart. The bundled accessories are the weak point too: gloves run snug, the goggles are basic, and riders repeatedly criticise the eyewear fitting over rather than under the helmet. Treat the bundled pair as a spare and buy your own goggles.
Is a bundled kit a sensible first helmet?
For a beginner on local loops, yes, because light weight and four published size ranges make a good fit achievable, and fit matters more than any feature here. The case against it is the warranty: 60 days is the only sub-year commitment among these twelve, and on a safety purchase that is a real signal about expected use.
Does it fit elongated head shapes?
This is the biggest limitation. The shape is listed as round, so a long oval head gets forehead pressure and a gap at the back, which elongated-oval owners report directly. If you are unsure of your shape, this is a poor first purchase and the Oneal Sierra or Bell MX-9 is safer. With only two vents, expect a warm helmet on hot days.
6. Bell MX-9 MIPS – The Best MIPS Helmet for the Money
- Genuine MIPS slip plane at a mid-range price
- Three shell sizes so you can match your head shape
- Ionic quick drying padding fights sweat and odour
- Removable liner and ear pads in multiple sizes
- Buckle can be finicky to undo with gloves on
- Slightly tight out of the box for some buyers
- Shell size coverage can be limited
Bell is the most widely recognised name on this list, and the MX-9 MIPS is where the brand makes most sense for a trail rider. You get a real slip plane, three shell sizes and the Ionic quick-drying interior, at a mid-range price rather than a premium one. Three shell sizes is the detail that separates it from most of the field: shell size and EPS size both have to match your head, and a helmet offered in one shell shape will never sit right across a range of heads.
Worth understanding what MIPS does: in an angled impact the slip plane lets the helmet slide a few millimetres relative to your skull instead of rotating the brain with it. The trade-off is weight, and the listed 3.75 pounds is heavier than the plain shells here. Ventilation is reported as good in hot summer riding, which partly offsets it.
Is MIPS worth the extra weight for trail riding?
For trail riding the case is weaker than for motocross, and honesty helps here. Your realistic crashes are slow tip-overs, low branches and a handlebar catching a tree at walking pace, where multi-density EPS does most of the work, while a slip plane is built for angled impacts with real energy. Still, a rider in the research reported that since switching to a MIPS helmet, low-speed tip-overs stopped leaving them with headaches and fuzziness. That is an anecdote, not a test result, but it is a consistent one.
What should I check before buying the MX-9?
Fit first. Some buyers find it slightly tight out of the box and describe a short break-in, and sizing is not uniform across the range, so make sure the shell size you need is offered. Then test the buckle with gloves on: that is the most-reported annoyance and the one thing that would annoy you every ride.
7. OUMURS Youth Dirt Bike Helmet – Best for Young Riders
OUMURS Youth Dirt Bike Helmet DOT Approved, Kids Full Face Motocross Helmet
- Light weight of 1.05 kg reduces neck strain for young riders
- Clear head size chart with four youth ranges
- Removable and machine washable liner and cheek pads
- Goggles gloves and storage bag in the box
- Included gloves can be too large for small hands
- Children outgrow the fit quickly
- ABS shell with no rotational protection
This helmet carries a 4.8 average across more than 1200 reviews, and the sizing explains it. Four youth ranges from 490mm to 560mm with a published chart let parents find an accurate fit instead of guessing between a small and a medium that were never distinguished.
Weight matters more here than anywhere else on this page. Children have proportionally weaker neck muscles, and 1.05 kg is a genuine reduction in strain. The listing states it weighs from 1050g, up to 20 percent lighter than typical youth models.
The construction is a high-impact ABS shell with a dense EPS liner, certified to DOT FMVSS No 218, with an adjustable detachable sun visor and goggles, gloves and a storage bag in the box. There is no rotational protection here and it is single-density, a fair trade for accurate sizing and low weight on family loops; for competitive junior riding, the Fox V1 carries MIPS and ECE 22.06 in youth sizes.
How do I pick the right youth size?
Measure head circumference and match the published chart rather than going by age. Growth is the issue: a helmet that is too small is genuinely unsafe because it can shift in a crash, so when your child reaches the top of a range, move up a size rather than forcing the current one.
What should parents watch out for?
The included gloves are the most common complaint, running too large for small hands. Fine as a placeholder, but buy a proper pair before a ride where grip matters, because a loose glove on the brake lever is a real control problem. Check the bundled goggles against the helmet too, since the fit is the part most likely to be replaced.
8. Giro Radix MIPS – The Best Fit Dial for Long Trail Days
Giro Radix MIPS Adult Dirt Bike Helmet – Matte Trail Green – Size S (51–55 cm)
- Roc Loc 5 dial adjusts tension and fore-aft tilt
- Integrated MIPS layer built into the fit system
- Large visor range including a goggle storage position
- Light at 1.6 pounds with a hard shell
- MTB-derived fit system rather than pure MX retention
- Smaller review base than the Bell and Fox models
- Less brand recognition in motocross circles
The Giro Radix is the odd one out in this roundup, which is exactly why it is worth considering: a mountain bike derived full-face helmet with an integrated MIPS system, a polycarbonate shell with an in-mold lower wrap, and a wind tunnel vent package at 1.6 pounds. The Roc Loc 5 fit system is the reason to look. One dial changes cradle tension and a second indexed adjustment sets fore-aft tilt, so you can dial the helmet to your skull shape rather than dealing with a webbing cradle.
Being honest about what it is: a bike helmet, not a motocross helmet. The retention is designed for MTB riding, so some riders find it unfamiliar next to an MX strap, and the two-year warranty is one of the longer commitments here. It also does not carry a listed DOT FMVSS 218 or ECE certification in the data we worked from, which is the main reason it is not higher in this ranking. Verify the marking on the shell before riding anywhere with a legal requirement.
Is an MTB-derived helmet fine for trail riding?
Frequently yes, and hard enduro riders increasingly choose full-face mountain bike helmets for that reason, reporting superior cooling and low weight next to MX shells. Certification is the one thing that can rule a helmet out entirely, so check that before anything else.
How does the Roc Loc 5 dial work in practice?
You turn one dial for cradle tension and a second for fore-aft tilt so the helmet sits level rather than sliding forward. For a long day that is worth more than it sounds, because pressure points you tolerate for twenty minutes become unbearable by hour three. The 549-review base is small next to the Bell and ILM models, so verify the sizing yourself.
9. Fox Racing V Core MIPS – The Best Magnetic Visor Release
Fox Racing Unisex-Adult V Core MIPS Motocross Dirt Bike Helmet, Matte Black
- Magnetic visor holds under roost but detaches in a crash
- Nine intake and four exhaust vents for a trail-ready matrix
- Four shell sizes and five EPS sizes for a precise fit
- MIPS and DOT FMVSS 218 together
- Listed weight of 5 pounds is heavy for trail riding
- Entry level model lacks audio integration of higher tiers
- Magnetic visor plate is an extra failure point if damaged
The Fox V Core is built around the trail use case, and the magnetic visor release is what convinced us. A bolted-on visor stays attached in a crash and can twist your head, while a magnetic release holds against roost and trail debris, then lets go under enough force to rotate away.
The vent layout is built for a long day: nine intake vents and four exhaust ports across an injection-moulded polycarbonate and ABS shell. That intake and exhaust separation is the specification that separates a trail helmet from a track helmet.
Fit is handled properly too, with four shell sizes and five EPS sizes. The problem is weight: the listed figure is 5 pounds, and no vent matrix fully compensates for that over four hours of single-track. Owners broadly agree the limit is the entry-level feature set, so if you want audio or comms integration, this is not that helmet.
Is a breakaway or magnetic visor actually safer?
Yes, and the mechanism is straightforward. Anything rigidly attached becomes a point through which force transfers to your neck in a fall. A visor that releases instead of pulling follows the same principle as breakaway road helmet shields, where it has been standard for decades, and rock strikes to the peak are ordinary on a trail.
Should I buy the V Core for a long trail day?
Only for moderate-length days. The vent matrix, sizing range and visor release are all strong, and two to three hours of mixed terrain is manageable. For a full day of technical single-track, compare it with the Fox V1, which carries ECE 22.06 and MIPS at a listed 1 kg. Note also that a damaged magnetic mount is a replacement trigger, not something to keep riding with.
10. Orthrus Dual Sport Adventure Helmet – Best for Intercom Riders
- Moulded headphone slots remove pressure points with a Bluetooth kit
- Plush removable washable liner with neck support
- Large visor is easy to operate and seals well
- Adjustable aerodynamic peak
- Only three vents so it gets warm in hot weather
- Outer visor is clear rather than polarized
- Large visor can lift at highway speed
- Runs slightly large so some buyers size down
Almost every helmet here forces you to improvise somewhere, and the Orthrus solves the one we found most annoying when riding with a group: intercom hardware. The headphone storage slots are moulded into the liner, so a Bluetooth kit sits in a recess instead of pressing on your ears through padding.
The rest of the package suits long distances too: a plush removable and washable liner with integrated neck support, three-point ventilation across top, front and back, and a large UV-protected outer shield with a hidden inner sun visor.
Three vents is the limitation to weigh, especially with a hydration pack on a hot day, and at 2.2 kg it is one of the heavier entries. Owners also report that the outer visor is clear rather than polarized despite some expectation otherwise, and that it can lift at highway speed. The shell prioritises road sealing over trail airflow, which is the right trade for mixed terrain and the wrong one for pure single-track.
Is this a good helmet for riding with friends?
It is the strongest fit for group riding of the twelve. The intercom slots are the differentiator, the visor is large enough to drop one-handed, and the liner and neck support hold up on long distances. If you do not use comms, none of that matters and you should weight ventilation more heavily.
What about sizing and the visor?
It runs slightly large, so some buyers size down, and the padding is thick enough to make that advice unusual and worth taking seriously. The most common complaint is an expectation mismatch: buyers expect a tinted or polarized shield and get a clear one. At low trail speeds the visor lift issue does not apply.
11. Fox Racing V1 Motocross Helmet – The Best ECE 22.06 Entry Helmet
Fox Racing Unisex V1 Motocross Dirt Bike Helmet, Pink, X-Large
- Triple certification including ECE 22.06 plus DOT and FMVSS 218
- MIPS low friction layer as standard
- Light at a listed 1 kg with excellent airflow
- True to size fit with replaceable cheek pad options
- The included cheek pads can be tight for some riders
- Double D-ring strap annoys riders used to buckles
- Street helmet noise and peak buffeting at freeway speed
Triple certification is unusual at this level and it is the reason the Fox V1 earns a place. It meets FMVSS 218, DOT and ECE 22.06, and it ships with MIPS as standard. Only one other helmet in this roundup carries ECE 22.06, and what that standard adds over the older one is rotational impact testing, the mechanism that matters in angled and oblique impacts. For a rider who wants that tested to a recognised standard rather than a proprietary claim, this is the affordable way to get it.
The weight is the headline: a listed 1 kg, well under the 1.88 kg and 2.2 kg of the mid-table options. Construction is stated as 54 percent ABS, 16 percent EPS, 15 percent paint and 15 percent PA, and owners describe the airflow as excellent for a pure dirt helmet. It is available from youth YS to YL and adult XS to XXL, with replaceable cheek pads.
Is ECE 22.06 worth choosing over DOT alone?
Yes, if you can compare like for like. FMVSS 218 is self-certification, meaning the manufacturer certifies the helmet and publishes nothing about how it performed. ECE 22.06 is type-approved against a published protocol and includes rotational testing that DOT does not cover. For a trail rider whose most common crash is a low-speed angled tumble, that documented test is more relevant than most buyers assume.
What are the compromises with the V1?
The double D-ring is a real friction point if you are used to ratcheting buckles, and it is the most common feedback alongside the cheek pad tightness. Expect street-helmet noise and peak buffeting at freeway speed. As an entry model it has no audio or comms integration, so plan on a separate solution if you ride with a group.
12. Alpinestars SM3 Off Road Helmet – The Lightweight ECE 22.06 Option
- 4.8 average rating
- Very light at a listed 16 ounces with good airflow
- Thermo injected shell with variable thickness
- True to size fit with no squished ears
- Small 128 review base means limited long-term feedback
- Cheeks fit tight for the first several hours
- ECE 22.06 is the European standard while DOT is the US listing
The Alpinestars SM3 carries a 4.8 average, the joint highest here, and a listed weight of 16 ounces, the lowest of any adult helmet on the list. It is also one of only two here certified to both ECE 22.06 and DOT, so it covers the US legal standard and the European rotational test in one shell. The shell is thermo-injected polycarbonate with variable thickness, adding material where impact energy concentrates instead of distributing it evenly.
The main caveat is evidence. With 128 reviews there is far less long-term feedback than for the Bell, Fox or ILM models, and on a safety purchase that thinner base matters. The one recurring note is a short cheek-pad break-in, though owners do report a true-to-size fit with no squished ears, a wide field of view with MX goggles and strong airflow. On the certification wording, ECE 22.06 is the European standard and DOT is the US listing, so the ECE badge is the one reflecting the harder rotational testing.
Is a 16 ounce helmet too good to be true?
The figure is real and achieved the honest way, through a lightweight shell and an efficient vent package rather than by cutting the liner. It sits well below the 1.6 to 2.2 kg of the mid-table options, and owners report a helmet they do not notice by hour three. The trade-off is that ultra-light shells have less material to absorb repeated abuse, so if your bike tends to fall over in the garage, a slightly heavier shell is reasonable insurance.
Who should buy the SM3?
Riders who want the lightest, best-ventilated helmet with documented rotational testing and who are comfortable with a smaller body of owner feedback. Alpinestars has a strong enduro and motocross pedigree, and a 4.8 average is a strong signal even from 128 reviews. Buy the Fox V1 if a double D-ring is a dealbreaker, or the Bell MX-9 if you want a larger sample of owner feedback to lean on.
How to Choose a Dirt Bike Helmet for Trail Riding
Fit comes first. Riders consistently frame the decision as the helmet they feel safest in, and that is not sentimentality. A helmet that slides on your head, rotates freely or presses on one temple is a helmet that moves in a crash, and preventing movement is what the shell and the slip plane exist for.
Safety certification: DOT FMVSS 218 vs ECE 22.06 vs Snell
Three standards appear on off-road helmets in the US and they are not equivalent. DOT FMVSS 218 is the legal requirement for motorcycle helmets on roads and on trails open to motor vehicles. It is self-certification: the manufacturer tests to the federal definition and publishes nothing about the results, so there is no independent ranking to compare against.
ECE 22.06 is the European type-approval standard that most enthusiast brands add alongside DOT. It is tested to a published protocol and includes rotational impact testing. ECE 22.05 is the older European standard that shares most of its testing with DOT but omits the rotational requirement, so it is a step below 22.06.
Snell is a separate American standard, and this is where the trail community splits hardest. On a long VitalMX thread about the safest helmet available, one rider wrote that the Snell rating is the first thing they look for and another wrote flatly that they would not buy one. Both positions have a real argument behind them.
Snell vs ECE 22.06: which one for slow trail tumbles
Neither, necessarily. The difference is what each standard is tuned for. Snell standards were developed around high-energy impacts, which in practice means road racing. ECE 22.06 was developed with a broader, lower-energy test range closer to what a rider experiences on a trail bike.
That maps onto a specific scenario. If your falls are slow tip-overs and low-speed rock strikes, a Snell helmet may be tuned stiffer than the situation requires, and a rider explaining that reasoning on the same forum thread put it plainly: softer helmets feel better in a low-speed tip-over. If you race enduro or reach highway speeds off-road, that argument weakens considerably. Practical advice is to buy dual certification where you can: the Oneal Sierra covers DOT FMVSS 218 and ECE 22.05, and the Fox V1 and Alpinestars SM3 cover DOT and ECE 22.06. If your trail access involves public roads, check your local authority too, since some parks and forest districts specify the standard on the sign.
Rotational impact protection: MIPS, Leatt 3F, 6D ODS, Bell Spherical
Multi-density EPS is the most basic form of rotational management, placing firmer and softer foam in different regions to shape how energy spreads. It is not a slip plane. A slip plane is a physical layer that lets the helmet slide a few millimetres relative to the skull, so the brain is not forced to rotate as hard in an angled impact.
MIPS is the most widely used slip plane and appears here on the Bell MX-9, the Giro Radix, the Fox V Core and the Fox V1. Leatt 3F and 6D ODS are the equivalents from other brands, and Bell Spherical takes a different approach with a curved shell mould. The honest caveat, repeated across the forums, is that no trustworthy independent data compares these systems head to head, so weigh them as a design philosophy rather than a proven ranking.
Shell material and helmet weight on a long trail day
Weight is the dominant trail-specific complaint, ahead of everything else. A helmet that feels fine after a 25-minute track session feels like a lead weight after four hours of single-track, because the neck muscles hold your head up against gravity the whole time. Listed weights here run from 16 ounces to 5 pounds, and that spread matters more on a trail than on a track.
Polycarbonate and ABS are standard and the most affordable. Fiberglass composite sits between that and carbon, spreading more energy for more weight. Carbon is the lightest and most expensive, and it earns its place mainly on long hot days. The Alpinestars SM3 at 16 ounces and the Fox V1 at 1 kg are the lightest adult options here, and the Fox V Core at 5 pounds is the heaviest despite a modern shell. Ventilation is the other half of the equation, because a well-vented helmet tolerates more weight, and if you ride in heat treat the vent matrix as a feature on the same level as weight.
Fit and head shape: measure before you buy
Wrap a soft tape measure around your head about two fingers above your eyebrows, level all the way around, and write the number down. Then check the published head circumference range for the shell you are considering. Brands that publish real measurements, like the OUMURS kits with their 570mm to 630mm adult ranges, are the easiest to fit from home.
Head shape matters as much as the number. Round oval heads are the most common and suit almost everything. Long oval heads need a helmet offered in multiple shell shapes, which is where budget helmets most often fail: elongated-oval owners consistently report forehead pressure on single-shape shells such as the round-shaped OUMURS kit.
Expect cheek pads to break in by around 10 to 20 percent, so a helmet that feels snug on the first ride may not be wrong. Do still check the 2-2-2 fit rule, which asks for two fingers of clearance above the eyebrows, two at each temple, and two between the cheek pads and your jaw. It was written for mountain bike helmets, which is why the Giro Radix fits it naturally.
Ventilation, goggle fit and hydration hose routing
Buy the helmet first and the goggles second. Goggles are almost always bought afterwards, and if the order is reversed they may not seat properly in the eyeport, pushing onto your nose and restricting breathing. Straps run under the peak on MX-style helmets and over it on MTB-derived designs, so match the strap geometry to the helmet style rather than forcing it.
If you wear glasses, eyeport width is a purchase criterion rather than a detail. The Oneal Sierra is called out by owners for a wide eyeport that works with prescription glasses, and the Alpinestars SM3 for a wide field of view with MX goggles.
Hydration routing is a trail-only factor that almost every roundup ignores. On a four-hour ride you are running a pack and the hose has to go somewhere. Most off-road shells route it through the chin bar area or down the neck, so if your helmet has a gaiter or neck roll, check that it has a channel rather than trapping the hose.
Our other guides cover the rest of a long day: bike computers for long routes and GPS computers for trail riders. If you also ride on the road, our commuter helmet guide covers the certified street side of the category.
When to replace a dirt bike helmet
Replace it after any impact, and this is the least discussed and most important item on the list. EPS is a crush liner: it works by permanently deforming to absorb energy, and once crushed it does not return to its original shape even if the shell looks untouched. There is no way to inspect it or test it, which is why the answer after a hit is always replacement.
Also replace it on age. The EPS, nylon straps and padding all degrade with UV exposure, sweat and time, which is why brands state a service life. Warranty terms here vary widely, from 60 days on the OUMURS adult kit to two years on the Giro Radix and the ILM 606V.
Do not use a second-hand helmet or one dropped hard from a shelf, and remove the cheek pads after a crash if the model supports emergency removal so a first aider can get in quickly. Replace the helmet, not the pads.
Frequently Asked Questions
What is the best dirt bike helmet for trail riding?
The best dirt bike helmets for trail riding combine rotational impact protection such as MIPS or a multi-density liner, a light shell to reduce neck fatigue over multi-hour days, and a high-airflow vent matrix. Certification should be at least DOT FMVSS 218, ideally alongside ECE 22.06 for documented rotational testing. Fit matters more than any feature: measure your head circumference and confirm the shell shape matches before you buy.
Is Snell or ECE 22.06 better for trail riding?
For trail riding, ECE 22.06 is usually the better fit. Snell standards are tuned for the high-energy impacts of road racing, while ECE 22.06 was developed with a broader, lower-energy range closer to what a trail rider actually experiences, and it includes rotational impact testing. Riders whose falls are slow tip-overs and low-speed rock strikes often prefer the softer feel of an ECE helmet. Hard enduro riders who reach highway speeds off-road may want a stiffer, higher-rated standard instead.
Is ECE 22.05 legal in the US?
ECE 22.05 is a European type-approval marking and is not itself the legal requirement in the US. US law requires DOT FMVSS 218 compliance for riders on roads and on trails open to motor vehicles. Many off-road helmets carry both DOT and ECE markings because the ECE standard tests to a published protocol that FMVSS 218 self-certification does not. Always confirm the DOT marking is present and check your local state park or forest district rules, since some specify a standard on the trailhead sign.
What does ECE 22.06 certification mean for a helmet?
ECE 22.06 is a European type-approval standard for motorcycle and off-road helmets that is tested to a published protocol by an approved laboratory, unlike DOT FMVSS 218, which the manufacturer self-certifies. Its defining addition is rotational impact testing, which evaluates how a helmet manages oblique and angled impacts rather than only straight-line impacts. That makes it the most useful standard to compare if you want documented rotational performance rather than a proprietary safety claim.
Do I need a MIPS helmet for trail riding?
It helps, but the case is weaker for trail riding than for motocross. A slip plane is engineered for angled impacts with meaningful energy, and a trail rider’s most common crashes are slow tip-overs, low branches and handlebar catches at walking pace, where a multi-density EPS liner does most of the work. If you ride hard enduro or race at speed, or you simply want the extra margin, a MIPS helmet such as the Bell MX-9 or Fox V Core is worth the extra weight.
What is the 222 rule for helmets?
The 2-2-2 rule is a fit check: two fingers of clearance above your eyebrows, two fingers of clearance at each temple, and two fingers of space between the cheek pads and your jaw. It was written for mountain bike helmets, where clearances are larger and glasses are commonly worn, so it is stricter than most motocross helmets require. It is still a useful sanity check, but on a low-volume MX shell the helmet should sit lower on the brow and the cheeks will break in by roughly 10 to 20 percent.
Which Dirt Bike Helmet Should You Buy?
The ILM 128S is the one we would buy first among these best dirt bike helmets for trail riding: DOT FMVSS 218 certified, a well-vented ABS shell over thick EPS, a liner that comes out for washing, and the largest review base behind it. Buy the Oneal Sierra instead if you ride mixed pavement and trail, because the integrated drop-down sun shield and second certification standard earn their keep. Buy the GLX GX23 if heat is your biggest enemy and you want maximum airflow for the least money.
Move up a tier when safety technology decides it. The Bell MX-9 MIPS is the sensible rotational-protection pick with three shell sizes, the Fox V Core adds a magnetic visor release and the widest vent matrix here, and the Fox V1 is the affordable way to get MIPS and ECE 22.06 together. If weight is what stops you wearing a helmet on a long day, the Alpinestars SM3 at 16 ounces is the lightest adult option on this list, and the Giro Radix MIPS is a strong second with a fit dial most motocross helmets cannot match.
Whatever you choose, measure your head first, check the shell shape, and replace the helmet after any impact. Then go ride.