As I approached the bar on my bike, I slowed down and swung my right leg up and over the back of the bike, starting my standard, quite possibly cool-looking transition from rolling to walking. Except this time, my leg didn’t make it. My heel caught on my pannier, my hands tightened inadvertently on the brakes, and I pitched up and over my handlebars. A moment later, my head took the brunt of my body’s collision with the pavement of San Francisco’s Mission neighborhood.

A few minutes later, nursing my drink and trying to hide the fresh hole in my jeans, I had two thoughts: first, how smart I was to be wearing my helmet at the time—a bit of a bruise on my leg was the worst of the damage. Second, how dumb I was for not wearing one most of the time.

In a perfect world, helmets would not be necessary. Cities would have protected bike lanes and enforce their speed limits, and movement on two wheels (or even feet) wouldn’t come with the added risk of a splatting. But in many urban places, where bike lanes range from shoddy to nonexistent, where ride-hail pickups and drop-offs threaten and inconvenience all, a bit of skull armor is a good idea.

I don’t mind wearing a helmet, but carrying one around is a pain. The thing's unyielding bulbous nature, so good for saving my brain, means it can’t be shoved into a backpack; clipped to the outside of one, it knocks about and becomes a major nuisance. And so even though I spend a lot of time on shared bikes, cycling between my office and the bus terminal, I often rode bare-headed, risking a damaging tête-à-cement.

Then a few weeks ago, I picked up the Closca collapsible helmet. It’s made up of three concentric rings of plastic and foam, which fit into one another, like one of those camping cups. Folded down, the helmet is about half of its expanded size, and while it’s still about two and a half inches thick, it’s flat and resembles the helmet Leia wore to fight alongside the Ewoks. And flat makes it easy to slide inside a backpack, messenger bag, or large purse. Distributed by cycling accessory line 174 Hudson and retailing for $80, the helmet weighs just under three quarters of a pound. (My own XS Skyline is just over a pound.)

For the past few weeks, I’ve been using the helmet pretty much every day, for the ride from the bus to my office, then back again in the evening. 174HUDSON It has become a key tool in my New Mobility Lifestyle. 174HUDSON

While one friend told me the Closca’s tiered style makes me look like New York’s Guggenheim Museum, I don’t think the helmet looks any goofier than its noncollapsible brethren. It breathes nicely, fits well, thanks to the adjustable straps, and meets the crash standards set by the Consumer Product Safety Commission. (Here's a nice video from Closca.)

For the past few weeks, I’ve been using the helmet pretty much every day, for the ride from the bus to my office, then back again in the evening. It has become a key tool in my New Mobility Lifestyle.

I, like a growing number of people, am an avid user of the various transportation options that have sprouted through the world’s cities, chief among them shared bikes (both docked and dockless) and scooters. In San Francisco, public transit is solid but often leaves me several annoyingly long blocks from where I’m going. The ability to take the bus, BART, or subway most of the way and then complete a trip without relying on a car or wasting time walking is a wonderful thing. But these new ways of moving come with the unavoidable risk of being doored by an inattentive driver or floored by an unfilled pothole. A helmet can’t keep you safe—again, better infrastructure is the answer there—but it’s better than nothing.

Now that it comes in travel size, there’s no more reason not to have one along for whatever the ride. Because even the world’s best cycling infrastructure can’t keep you from flinging yourself off your bike once in a while.

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