Giro Prolight v. Atmos

• I misplaced my helmet the other day, and instead of heading out for a four hour ride without one, I grabbed the one nearest the door. It turned out to be the controversial Giro Prolight, size medium, in black.

  When it was announced over a year ago, the Prolight was ridiculed for its somewhat frumpy, retro styling. It lacks the carbon struts of Giro's racing helmets. Its vents were smaller. Its profile was less rakish. And in some colors (such as the unfortunate all-orange Prolights sometimes worn by the Garmin riders) it looks like it was designed for children. It lacks any real adjustability. But one thing is for certain: it delivers on the promise of light weight. My medium (sans decals) tips the scale at 196g, versus 273g for the already relatively light Giro Atmos.

  Having ridden the Atmos for much of the year, I was already familiar with the pros and cons of Giro's current slate of helmets. While the Ionos does have better padding and more secure fitting system, it was too similar to the helmet I was replacing at the time, the Spiuk Nexion. Both are extremely comfortable, if somewhat heavy (>300g) designs -- and I wanted to try something different this year. The Atmos has superior venting and is surprisingly cool when worn without a cap. Dumping a bidon of water over one's head actually results in... a wet head! The helmet's profile is pretty racy, but does ride high on some folks. It's clear that the weight savings comes at the expense of foam around the temples. But the worst thing about the Atmos is the padding, or lack thereof. Long rides often result in sometimes painful impressions of the helmet's center struts on the forehead, as often exhibited by Levi Leipheimer. Unfortunately, there's not a lot that can be done about this, other than very carefully tightening the tensioning system, and then backing it off one click after it seems tight.

  Without any adjustability, the Prolight either fits... or it doesn't. Fortunately, I found that the medium does fit my head pretty well -- better in fact than a medium Atmos. Some have complained that the Prolight suffers from poor ventilation, and I suppose this is possible. The vents are smaller than those of the Atmos, though they are just as deep. It's not something I have been able to sense, even on a handful of ridiculously hot rides. But perhaps I don't really ride rapidly enough for a helmet-windchill to take effect.

  The Prolight is some 77 grams lighter than the Atmos, and over 100g lighter than my Spiuk, which doesn't seem like much. And yet somehow, it feels far lighter than either of them. In this way, it reminds me a lot of my old Specialized Sub 6. I suppose a gossamer helmet doesn't have any real bearing on performance -- that is, unless one does a lot of head bobbing, or more importantly: repeated head butting... but it just feels right to me. Like tubulars or carbon handlebars, the Prolight isn't for everyone -- but it provides a discernibly different riding experience. And that's worth something.

  Giro Atmos, $175

  Giro Prolight, $200

  Giro Ionos, $230

  TATI stocks all three models. However, Giro is sold out of most colors and sizes -- so call/email for availability.

  
  

  The Prolight has very minimal padding, but so does every other Giro.

  

  Even the hardware is slightly different. The straps and plastic bits are completely unique to the Prolight.

  

  Not all that different from behind, really.

  

  Can you tell which is which?

  

  The Atmos (at right) clearly has bigger vents.

  

  The stretchy retention device feels fine to me, but isn't for everyone.