MTB Helmets for Safety on Trails

Mountain Bike Helmets: What to Know Before Buying

Mountain bike helmet shopping has gotten complicated with all the safety certifications and marketing claims flying around. As someone who’s crashed enough to appreciate good helmets, I learned everything there is to know about what actually protects your head.

Had a rock-strike that cracked my cheap helmet in half but left my head intact. Upgraded the next day. Here’s what I’ve learned about the category.

Trail Helmets vs Full Face

Probably should have led with this section, honestly.

Trail/XC helmets: Open-face, lightweight, maximum ventilation. Standard for most mountain biking. Protects the top and back of your head. Your face is exposed.

Full-face helmets: Chin bar protects your jaw. Heavier, hotter. Mandatory for downhill/bike park riding. Some people use them for all aggressive riding.

Convertible helmets: Removable chin bars. Climb with it off, descend with it on. Compromise solution – chin bar protection isn’t as good as dedicated full-face.

For most trail riding, a good trail helmet is fine. If you’re doing lift-served descents or genuinely scary terrain, full-face makes sense.

MIPS and Rotational Protection

MIPS (Multi-directional Impact Protection System) is a liner that allows the helmet shell to rotate slightly on impact. This reduces rotational forces that cause brain injuries.

Does it work? The science is solid. Real-world evidence is harder to prove, but it’s physics – rotational forces are reduced by allowing slip.

Other systems exist: SPIN from POC, WaveCel from Bontrager. All address the same problem differently. Any rotational protection system is better than none.

Worth the extra $20-40? I think so. Brain injuries are permanent.

Coverage and Protection

Trail helmets extend further down the back of the head than road helmets. This matters because mountain bike crashes often involve falling backward onto rocks.

Look for helmets that cover your temples and wrap around to the occipital bone (base of skull). Cheap helmets often cut coverage short.

Ventilation vs Protection Trade-off

More vents = cooler head = less material = less protection. There’s always a trade-off.

XC race helmets prioritize ventilation because XC riders climb hard and rarely crash catastrophically. Enduro helmets have fewer, smaller vents but more coverage.

For hot climates and fitness-focused riding, prioritize vents. For aggressive terrain, prioritize coverage.

Fit Is Non-Negotiable

A helmet that doesn’t fit right won’t protect you properly. It should be snug without pressure points. When you shake your head, it shouldn’t move independently.

Most helmets have adjustable retention systems – dials or straps at the back. Get the shell size right first, then fine-tune with the adjustment.

Try before you buy if possible. Head shapes vary and not every helmet fits every head.

Helmets Worth Considering

Giro Source MIPS: Great all-rounder. Good vents, good coverage, good price. Works for most people.

Troy Lee Designs A2: More aggressive styling, excellent ventilation, premium quality. Popular in the enduro crowd.

POC Tectal Race SPIN: Excellent coverage, distinctive look. POC’s build quality is excellent.

Bell Super Air R: Convertible with removable chin bar. Good option if you want one helmet for all situations.

Smith Forefront 2: Koroyd technology for impact absorption. Different approach than MIPS, arguably more protective.

Replacement Schedule

Replace after any significant impact. Even if it looks fine, the foam may be compromised.

Replace every 3-5 years regardless. Materials degrade from UV exposure, sweat, and age.

Don’t buy used helmets. You don’t know their history.

What to Spend

That’s what makes helmet protection endearing to us mountain bikers who’ve had close calls. $80-120 gets a good helmet with MIPS and adequate coverage. The Smith Session or Giro Fixture fit here.

$150-200 upgrades fit, ventilation, and features. This is where most serious riders should shop.

$200+ adds marginal improvements. Worth it for racers, overkill for recreational riders.

Under $60 usually means compromises somewhere – protection, fit, or durability. Your head deserves better.