Railing Berms in the Giant Rail SX MIPS Half Shell Bike Helmet [Review]

Another good lookin' trail helmet with MIPS protection and a goggle strap holster.

When the Rail SX MIPS half shell from Giant arrived, my immediate thought was “this helmet looks light.” The external plastic shell stops short of covering the lower edge, leaving some of the foam EPS layer exposed, and the chin strap latches closed with a simple “trident” style clicker instead of the glove-friendly Fidlock that much of the competition is using. Alas, at 410g (size large) it’s a fairly average weight lid with some cool features to note.

On the safety front, the Rail SX includes a MIPS insert to help redirect rotational impact forces, alongside what Giant calls “Optimized low-density EPS” foam to absorb the direct hits. As is common in MIPS-equipped helmets, there is a consistently audible creaking between the layers while riding that may agitate some folks. It’s certainly not as pleasant as the calm crackle of leaves under tread that most of us have grown to love.

A comfortable layer of anti-microbial padding lines the inner front half, working with the eighteen intake and exhaust vents to keep your head dry and odor-free. I would love to hear how some alopecic or clean-shaven riders feel about these modern helmets that only have padding in the front half. I have noticed that a lot of those riders have a series of sharp lines on the back of their scalps when the helmet comes off, but is that problematic or painful while pedaling?

For my heinously thick-haired scalp the Rail SX has a comfortable fit, and the vents seem to dry sweat fairly well. This is not the coolest nor breeziest lid for summer riding, and it’s also far from the hottest.

Both sides of the retention system are individually adjustable.

The overall fit of this half shell is spot on with the Giant size chart, and it falls into the “forgettably comfortable” bin on longer adventure outings. The angle of the retention system is micro-adjustable between five different positions, which should help anyone dial it in to their unique face and dome shape. The adjustable ratcheting ring wraps the entire circumference of the helmet, preventing unwanted sharp spots when it’s tightened down. I have experienced some difficulty keeping the Rail SX from sliding forward while descending, but a quick tightening of the ratchet wheel at the top and loosening at the bottom solved that.

The visor is infinitely adjustable through about four inches of travel, and tightens in place with a pair of hex bolts on either side that can also be finger tightened. I originally thought the visor looked flimsy, but it has been banged around regularly and remains in place, functioning properly. The two retention bolts can be adjusted individually, and unless you want a lopsided bill it is best to set it and forget it.

There is space to mount an action camera under the visor, but given the issues I had with the shell sliding forward, I didn’t want to add weight to the front end. There’s a wide spot in the top-center that’s likely the best place to glue lights and cameras for action.

Finally, what about my goggles? Giant has included a snap system on the rear end to keep a goggle strap in place. It quickly snaps on and off with one gloved hand and has been sturdy enough to keep my goggles planted all day. It might also work well to hold a headlamp battery cord in place for nighttime fun.

The Giant Rail SX MIPS comes in grey, red, black, and blue, and retails for $165. Available online at Amazon.

Thanks to Giant for sending the Rail SX MIPS over for testing and review.