Cyclists all wear helmets for the unthinkable situation when we will inevitably end up on the ground. Whether you are most concerned about sharing the road with cars or coming face-to-face with a trailside boulder (note: I did the latter) – a helmet is a simple insurance policy.
Now, I review a lot of new helmets when they are launched, and try to report back on what’s new and unique about each. But I usually attempt to evaluate them exclusively on how safe they make me feel, how comfortable they are to ride in, and how they deal with me sweating profusely.
I consciously try to avoid “testing” their impact protection first-hand.
Well, last week I tested one out. And yes, it likely saved me from some serious injury.
Then, I cut it open to see what happened inside!
Actual real-world mountain bike helmet testing is not advised!
So now, I am writing this as part Op Ed, and part product review.
But at the same time, it is also a quick explainer of what’s inside a modern cycling helmet that aims to make you and me safer than ever.
For a tiny bit of backstory…
That slightly smashed up (now dissected) helmet is a halfshell Leatt MTB All-Mtn 3.0 mountain bike helmet that came out two and a half years ago.
It is was not the lightest (~415g for my size M), most ventilated, or fanciest helmet I have used. But it was very comfortable, managed sweat quite well, felt very secure on my head, and packed in some simple but seemingly effective safety tech – like a 3-piece shell, 360° Turbine thingies inside & an easy-to-use Fidlock buckle.
And it only costs $150€, which seems pretty reasonable.
There are several new colors of this helmet now – although I prefer my MY23 Pine green color. Also, Leatt offers a 3-year helmet crash replacement program, which means that post-crash, I would also be eligible for 40% off a replacement.
Leatt.com for more info.
JRA
Now for the crashing.
(Trigger warning)
I wasn’t doing anything especially crazy. Yes, I was riding some notoriously technical local trails, with plenty of rocks like those photographed above, just minutes before I hit the deck.
But I crashed on a seemingly tame, less steep section.
It had been raining for a couple of days, after an already-wet end of summer, and I simply slipped on a root. There are so many roots on our local trails that I didn’t really give extra attention to this one. And in an instant, my front wheel slipped out from underneath me, my hand parted ways with the bar, and I was hurtling head-first to the foot of a car-sized boulder, where there were, conveniently, some smaller head-sized boulders to cushion my fall.
No time to think or really react, my body slightly rolled, and I went face-first to the ground. Temple directly onto a rock, with a bit of face scraping another rock, too. In the blink of an eye, I went from casually ‘just riding along’ to lying on the trail looking up with my bike on top of me.
But honestly, I was fine.
The helmet took the brunt of the impact. No real immediate pain other than a couple of cheek abrasions. And I was able to get back on the bike, finish out a slightly shorter version of the ride than originally planned. And walk away with a couple of scratches and slightly sore neck & shoulders when I arrived back at the trailhead.
I am 100% sure that I would not have ridden out if I didn’t have a helmet on.
So what did the helmet do to protect me?
So here is the “opinion” piece.
I’m no helmet safety engineer, but I’ve listened to several explain how this works over the years. So, I wanted to visualize what was protecting my head in this Leatt All Mountain 3.0 mountain bike helmet.
And knowing that once you crash a helmet – even if outwardly relatively minorly, it is not safe to rely on it anymore – I thought I would cut it open to see what safety features were lurking inside. I was, after all, curious what the 3-piece shell & PowerBridge meant.
Right after my crash, I could first see a visible dent in the outer shell. And feel a soft spot under the shell where the EPS had compressed.
I also saw the visor broke away as designed, not to catch, as my body might have been rolling. (I actually needed to zip-tie the visor in place to finish the ride.)
But because this helmet fully encapsulates the EPS foam in a thin wraparound polycarbonate shell (as do most modern MTB lids), that inner EPS didn’t really break apart at all – like I remember happening with older, less sophisticated helmets in years past.
There are also Leatt’s little blue 360° Turbine doodads inside. They aim to reduce rotational impacts – although mine was more of a straight-on smash.
Before cutting into the helmet, I also noticed that the bracket that held the visor got pushed into the shell further than I had first noticed. Clearly, some more impact damage there.
Modern mountain bike helmet post-mortem
Opening up the top outer green shell of the helmet, I was surprised to see that the EPS foam actually was co-molded over top of the main wraparound shell with red contours. Also green on top where the lower shell poked through, visible crossing the left & right vent openings on top.
I think this lower shell wrapping over the top in the middle of the EPS is probably what Leatt calls the “PowerBridge in-molded force absorber“.
Inside the helmet, I also found it a bit odd that at least 3 different types of tape seem to hold all the separate parts in place before the EPS was injected to fill the multi-part shell. I guess it is quite complicated to in-mold all of the separate elements below, and the tape must not really impact structural integrity.
That red contour wrap-around shell also overlapped the lower all-red shell, which protects the compressible EPS foam from everyday handling abuse. It also seems to tie everything together quite securely.
Inside, I found a stiff, rough yellow ring of what looks like aramid or fiberglass fibers, encircling the top vent to keep the helmet together in a top or rear impact.
And across the lower front, there is a much more complex, smooth & flexible white skeleton that seems to hold the helmet together in a frontal impact. This is almost exactly where I hit a rock with my helmet – just below the front left vent opening (opposite side to where I cut into the helmet after the fact).
My assumptions about modern helmet safety
I suspect the EPS did its job, compressing to absorb some of the impact energy.
Then, that inner plastic skeleton helped the EPS foam stay together as it compressed, allowing it to distribute the energy across a wider area of my head. The soft blue rubber 360 Turbine rings may have helped disperse energy around my head. Or they just slightly cushioned the blow like the helmet’s inner padding.
The result – I did get a temporary knot on my head just under the impact area. Maybe a subtle headache that I noticed a couple of hours later. And lastly, some very minor neck and shoulder soreness. But, all in all, I walked away – rode away in fact – from what looked like a pretty serious head-on impact with some boulders.
(That was the immediate assessment of the situation from my wife, who was riding right behind me when it happened. Sorry you had to see that dear, but glad you were with me.)
And my takeaway is this: Current helmets are pretty awesome.
They combine classic in-mold EPS energy-absorption construction with additional specialized safety tech to offer better head protection than ever. I’ll keep putting one on, every time I throw a leg over a bike.
