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Mainline Mips Full-Face Helmet

4.6743421052631575 out of 5 stars
304 Reviews
$217.00 - $310.00
Up to 30% off
Color:Matte Archive Wildchild


Size Chart


Why We Like The Mainline Mips Full-Face Helmet

Smith makes their debut into the world of ultra-light full-face helmets with the all-new Mainline MIPS. Featuring extensive ventilation and lightweight yet tough construction, this helmet offers the airy feel of a half-shell while providing downhill-certified coverage for a boost of confidence on rowdy trails. Advanced protective features include Smith's unique Koroyd crumple zones that go above and beyond to disperse impact forces, as well as a MIPS protective layer that helps mitigate harmful oblique impacts.


  • Smith's lightweight full-face for enduro and downhill
  • ASTM certified for downhill mountain bike racing
  • 21 vents keep you cool during summer shred sessions
  • Koroyd layer provides superior impact absorption
  • MIPS protects against oblique and rotational impacts
  • Comes with multiple pad sizes to ensure a proper fit
  • D-ring fastener is lightweight and super secure
  • Anti-odor pads are removable and washable
  • Item runs small, so we recommend sizing up for best fit
  • Item #SMIZ99F
downhill, enduro
Audio Compatible
ASTM F1952-15, Complies with U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older
Fit Adjustment
3 different sizes of cheek pads, 2 different sizes of crown liners, 2 different sizes of neck rolls
AirEvac system (21 vents)
Manufacturer Warranty
Claimed Weight
[large] 1lb 15.6oz
Shell Material
Aerocore in-mold polycarbonate

Overall Rating

4.5 based on 304 ratings

Review Summary

1 Stars - 5 reviews
2 Stars - 1 reviews
3 Stars - 15 reviews
4 Stars - 46 reviews
5 Stars - 237 reviews

Fits Slightly Small

Screen reader users: the following list provides a visual scale to illustrate the product fit. Please refer to the heading above for the fit type in text.
Runs smallTrue to sizeRuns large

What do you think about this product?


Selecting an option will reload the available reviews on the page
3 out of 5 stars

February 13, 2024


I might get some backlash here, but I may be the only one that hates this helmet. Pros: -Lightweight -Breathable -assorted cheek pad sizes Cons: -No rear tension for a snugger fit -Chin strap is impossible with gloves on *prefer a quicker release like the Bell Quick Air chin strap -sizing is off, the med didnt feel secure on my dome and a small was too snug -i cant pull up my goggles for a quick breather, they flop right back into your face I wore this helmet once on a longer ride and was so ticked the whole time. I fumbled with my gloves every time i wanted to take it on and off for a breather. And i know its not just me because my friend has this helmet and its annoying with the chin strap and gloves. I didnt like how lose it felt, i had to have the chin strap basically choking me and even then i just didnt like the fit. If Smith adds a rear tension adjustor and an easier way chin strap i would love it. Just not for me. Lame.

Ingrid J

Originally reviewed on Backcountry.com

5 out of 5 stars

February 6, 2024

I've owned Smith ski helmets, first Smith bike helmet.

Great fitting, great looking, confidence booster. I haven't taken a fall with the Mainline, but feel that it will keep me safe if that day comes.


Originally reviewed on smithoptics.com

5 out of 5 stars

October 13, 2023

Le casque est parfait! Il

Le casque est parfait! Il est super confortable et le design est simple comme j’aime!

Sophie L.

Originally reviewed on smithoptics.com

5 out of 5 stars

August 23, 2023

Did it’s job well

Saved my wife’s face on a fall. This helmet did its job well and bought another one.


Originally reviewed on smithoptics.com

5 out of 5 stars

July 22, 2023

A great replacement for my old full face

I use this helmet for work and it’s making wearing a full face in this heat bearable. Love the Matte Black look and the vents to keeps cool. The MIPS is great, but can sounds a little creaky when coming down rough stuff. Not very distracting though. Would still recommend it to anyone looking for a lightweight downhill helmet.


Originally reviewed on smithoptics.com

4 out of 5 stars

June 22, 2023

Great for fast downhill runs

1 year of use later.. The mainline is fantastic when it's either below 60f or you are getting lots of air circulation on a fast downhill. As soon as your not moving fast enough on a day upwards of 75f you can't get this helmet off fast enough. The rattling issue is not an issue if you wear a sweat wicking cap under, which also improves general comfort. As far as crash protection, I took a huge spill bashing my noggin into rocks, the bike, and ground and the helmet held up amazing. It protected my skull from being split open and my face from being pulverized.


Originally reviewed on smithoptics.com

5 out of 5 stars

June 18, 2023

Smith helmet

Amazing comfortable helmet, looks great and is really light and hard to get over heated in.


Originally reviewed on smithoptics.com

5 out of 5 stars

March 11, 2023

Amazing fit

Secure and fits right. Comfortable and light enough to now worry. Great look and great vents.


Originally reviewed on smithoptics.com

5 out of 5 stars

February 14, 2023

Wrecked it - shipped to ER with head trauma. I'm buying another one the next day.

I don't think I'd be sitting here easily ordering a new one today if I was wearing a different helmet yesterday. Absolutely solid piece of equipment, head injury could have been much worse if I was wearing something that sucked. Well done.


Originally reviewed on smithoptics.com

5 out of 5 stars

February 13, 2023

Best Helmets!

We love Smith! My wife and I love these helmets. We already have open face Smith helmets for MTB and Snowboarding and skiing helmets. These are so lightweight and comfortable. We both change our chin pads for optimal fit. Lots of vents for the hot days high in the Rocky Mountains of Colorado.

derek c.

Originally reviewed on smithoptics.com