Smith Mainline Helmet Review


Review by Nic Hall

With bike technologies and our skills (or lack thereof) progressing, half shell helmets leave us feeling a bit vulnerable. More often than not we find ourselves reaching for a pedal friendly full face instead, even on longer pedal rides with steep descents. After a hard slam to the face where the Smith Forefront prevented me from a serious head injury, I was stoked to see the Smith Mainline show up at the office.

Smith went back to the drawing board with several objectives for a pedal friendly full face: Protection, Airflow, Fit, and Weight were all at the top of the list. The Mainline is the result of several years of testing and development with their pro athletes. But is 800g of Koroyd protection with a DH certified chin bar and half shell breathability… too good to be true? We rode it for the last few months to find out.

Smith Mainline Helmet Review

Smith’s Mainline relies heavily on a unique material to balance safety and breathability. Koroyd, which looks like a bunch of straws glued together, has superior energy dissipation when compared to traditional EPS construction but breathes well while remaining lighter than EPS only helmets. Smith employs a MIPS system, a layering of Koroyd, an EPS inlay, and a hard outer shell to give the Mainline EN1078, CPSC 1203, and ASTM F1952 ratings. In normal English that means the Mainline protects as well as any full DH racing helmet, including the chin bar.

Brining all that protection and tech into a comfortable package is where the rubber meets the road. Smith includes two sets of crown liners, three sets of cheek pads, and two neck rolls to make sure you can dial in the fit to your head. They also took eyewear into account, incorporating “AirEvac” channels that move hot air away from the google area and out exhaust vents. The eye port is designed to work with googles as big as the Squad XL, so fitting some big frame goggles should not be an issue.

Airflow is handled by 21 fixed vents and an adjustable visor that channels air into the brow and crown vents. The chin bar has a large intake right at the mouth level and all vents are free of mesh or foam that could restrict airflow. An Xstatic XT2 anti-bacterial liner and washable pads keep stink at a minimum. The Mainline is secured by a double D-ring strap, which we’ll get into later.

Smith Mainline Helmet Review

Setup on the mainline is strait forward. Simply choose the shell size for your head measurements and fine tune the fit with the included neck rolls, cheek pads, and crown liner. I was able to get the helmet set up and fitting snug within a few tries. The fit is similar to a traditional full face, but with less contact on the sides and top of your head. The only downside of the entire helmet is the D-ring strap system. It is very tight and flush, making it hard to operate with gloves on. For a $300 helmet, we would like to see a Fidlock style closure next time.

Complaints about the closure mechanism aside, this helmet is extremely comfortable once it’s on. I can feel the significant improvement in interior airflow even in low speed pedaling situations. Passive venting is still warmer than an XC lid, but I feel it’s justified by the level of protection. At speed, the Mainline has about as much airflow as any modern, full coverage enduro helmet. I never find myself gasping for breath on the climbs or claustrophobic when things get warm. The side vents on the chin bar also help airflow feel natural and unfettered.

Smith Mainline Helmet Review

Based on previous head slam testing, Koroyd is a solid energy reduction system and when coupled with a MIPS liner it most definitely saved me from a serious head injury. Now add to that a fully rated DH chin bar, and you have the total protection package. I truly feel more confident wearing the Mainline, especially when I want to up the speed on local trails or try a new drop for the first time.

Goggle integration is outstanding, which should be expected from Smith. Wearing the squad goggle provides a huge amount of airflow. Even when climbing in wet conditions, I rarely see condensation or fog on the lenses. If things do start to get foggy, I just throw the goggles on backwards with no issues. I tried a few different goggles and frame designs with no issues at all. The visor is also adjustable if you just want to run your goggles below the visor on a climb, but it blocks off the forehead vents and things get warm quick.

Smith Mainline Helmet Review

The Wolf’s Last Word

You are running out of excuses to not wear a full face on most rides and the Mainline is the proof. Loads of airflow, protection at a DH level and a custom fit set the Mainline at the top of the pedal friendly full face market for me. The only thing I would like is a better closure system. That being said, the Mainline now lives in my gear bag full time, which is the highest praise we have to give.

Price: $300
Weight: 804g

Disclosure: Our team selects all of the products we review and do so with honesty and objectivity in mind. Some of the products we receive come directly from Competitive Cyclist, who also value our readers and have offered them a 15% discount (exclusions apply) on their first purchase by using LOAMWOLF15. Through this program we may also receive a small commission at no cost to you. Thanks for your support, TLW.

We Dig

Comfort and Fit

We Don’t

D-ring buckle system


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