Consider my first crash in the summer of 2008. It was during a criterium, in a tight corner with too much contact. My teammate Carol and I fused from hip to shoulder by the vortex of the turn, her weight bearing down on me, pushing me further into the lean. I lost control. The moment passed so quickly that I couldn’t brace myself for the impact. I went headfirst, slamming into the pavement. My body followed, jarring and scraping its way down the road. Then stillness. I remember being afraid to move. Afraid of what had become of me.

Despite the hematoma over my right eye, the achy neck, and the persistent headache, my head trauma turned out to be minor. Still, when my friends saw my condition their eyes widened in horror. “How do you feel?” they would ask. “Relieved,” I’d say, “and amazed.”

Mostly, I was amazed. How does someone just walk away from something like that? A 25-mile per hour impact with pavement can kill you, particularly when your head is the first thing to hit the ground. Seven hundred cyclists died on U.S. roads in 2007. About 540,000 bicyclists visit emergency rooms with injuries every year. Of those, about 67,000 have head injuries.¹

I examined my helmet, Giro’s top-of-the-line Ionos, for damage. No cracks, just a small scratch on the white and silver shell. I’m sure my bare head would not have fared as well. In a report issued by New York City in 2005, nearly all bicyclists who died there (97%) were not wearing a helmet.²

It wasn’t luck that my helmet (or my person) emerged unscathed from my first crash. Nor was it attributable to Giro’s technology actually. I have a confession: I purchased that helmet solely because Alberto Contador wore it, not because it was necessarily better or safer than other brands.

That shiny outer shell, the first of three layers found in all helmets, is what allowed my helmet to skid easily on the pavement to avoid jerking my neck. The second layer, the stiff foam beneath the shell, is what cushioned my blow, reducing the peak energy of the hard impact. Pretty much all helmets use crushable expanded polystyrene (EPS), which is the same foam found on those old white coolers. The third layer, consisting of squishy pads fit to my skull, receives no credit for injury prevention, but gets points for comfort and fit.

The main price differential in helmets appears to be, you guessed it, based on looks. My helmet looks sweet. Pro team usage also plays into price, as does ventilation. Consider that Giro’s in-mold composite sub-frame has the strength to support 21 very generous-sized vents (or as Giro claims, 21 of the largest vents ever carved into a helmet). Allegedly, it’s cooler than even a bare head. I paid $230 for this feature.

Manufacturers will try to sell you on their brand’s high-tech fit, but the fit is really your responsibility. Not every brand will fit every head. Guidelines for properly fitting a helmet can be found on the Bicycle Helmet Safety Institute’s site. If my helmet had not stayed put after the initial impact, I would have been in serious trouble. Momentum from a crash usually causes you to hit your head several times. It’s the fit that keeps the helmet in place.

Another item for the “your responsibility” category is replacing your helmet every 3 to 5 years, depending on the manufacturer’s recommendations. And a helmet must always be replaced after a crash. Just because you don’t see any damage, like I didn’t with my Ionos, doesn’t mean the helmet has not incurred any. Remember the term crushable expanded polystryrene? One hit, and it’s done.

Even so, I couldn’t just throw my Ionos away. It had, after all, saved my life. So I hung it up in my garage, as shiny as the day I bought it. It looks like a halo hanging over the rest of my bike gear.