Giro Prolight Helmet
We were underwhelmed with the new Giro Prolight product launch at the Tour in 2009. Arcalis. From some angles, the helmets looked like older Giro helmets, like those from the early '90s, from other they looked like mid-level helmets, almost like Giro's Saros and Stylus models, and there were a few shots where the helmets looked pretty high-tech.
Word quickly spread that the helmets were the lightest brain buckets Giro had made in years and lighter than anything else on the market. There was chatter about "Italian" nylon straps. Sure, Italians are known for their shoes and saddles, and the Giro name is indicative of the generalization that Italian is synonymous with style. But Italian nylon seemed silly.
Pick up the helmet and all the criticisms vanish. The Prolight felt as if it weighed about half of our other helmets. After we got over our awe, we proceeded to weigh our Prolight and then every other helmet we had in the house. Our Prolight weighed in at 190g. Our Bell Sweep R is at 290g, Giro Ionos 310g, Rudy Project Sterling 340g, and Rudy Project Actyum 350g.
We can laugh about Italian nylon straps, but they feel finer, thinner, even more sophisticated than other helmet straps. They're not glossy, have little heft, and no stretch. They're more like firm ribbon than like typical helmet straps. Most straps seem to be double-layered; these are single-layered. The straps, along with other elements of the helmet retention system account for a sizeable percentage of the weight savings. There are no adjustable buckles where the straps meet. These points are nothing more than double-layers of strap material stitched together. And the strap that goes under your jaw isn't designed to be cut down and it's not held in place by an easily-lost rubber band. This strap has an end that is permanently affixed to the helmet as well.
We worried that the fixed points won't fit many people. Giro claims that they've measured lots and lots of heads over the years and have developed "head forms" that allow them to base the placement of the straps on composite heads. They've been using these for figuring where to place the straps in the helmet at the temples and back even with the Tri-lock adjustment system. With the Prolight, they sent samples to their teams at the 2009 Tour, not only to make a public relations splash, but get valuable feedback from people who have to wear helmets six hours at a time while groveling over their handlebars. And, not surprisingly, after the product crossed el Lance's path, they had to make some tweaks, in particular, drop the fixed point a bit lower to accommodate his ears. With this adjustment, Giro believes the points they fixed should fit something like 95% or more of potential helmet users.
Another major simplification is the secondary retention system. Giro's Roc Loc has been getting more sophisticated as they've evolved it. The Roc Loc SL employed here, goes the other direction. It seems like a hybrid of earlier Roc Locs. The elastic at the back, the section that has "Giro" embroidered in it, is a stretchy elastic band out of their earliest Roc Locs. The side sections, which look kind of similar to the Roc Loc sections on the Giro Eclipse, don't stretch at all. They system adjusts in two ways. The elastic "customizes" the fit, with the side sections adjustable from three starting points by your temples.
The helmet comes with the Roc Loc SL set in the middle adjustment position. When we first donned the helmet, this position felt perfect. The elastic at the back of the Roc Loc seemed to be stretching just a little bit. So we tightened the "chin" strap and rode. Within an hour, we realized the folly of our confidence. The front of the helmet seemed to be digging two divots into our skull. We took off the casque and adjusted the Roc Loc to it loosest setting. Now, when we put on the helmet, the Roc Loc doesn't feel engaged at all, but once the strap is locked under our jaw, the elastic starts to stretch and the helmet remains in place for the rest of the ride.
Those used to the Roc Loc 4, found on the Ionos, Atmos, and Saros might need a little time to get used to the SL. With the 4, you can tighten the Roc Loc until it is snug and back it off a click or two and the Loc will hold without feeling like it is putting any pressure on your skull at all.
We definitely felt there were some transition issues with this new Roc Loc SL. There are times when we wonder if the Prolight is putting permanent divots in our skull where the forward-most Wind Tunnel vents rest against our head. We think this unlikely, but at the end of long rides, when we see the red spots on our forehead, the thought crosses our mind. This also occurred when we first tried the Giro Ionos, so it could be the shape of our noggin doesn't quite work perfectly with the skull form Giro designs around.
You can tell from looking at the Prolight and the feeling is confirmed when you're wearing it, that the silhouette is closer to the mid-level Saros and entry-level Stylus than it is to the high-end Atmos and Ionos helmets. The smaller silhouette is partially a result of the smaller vents. More material closer together doesn't need to be quite as thick. And the smaller vents help keep the weight down.
We had two questions about the smaller shape. One is whether or not it would be as cool to wear as the Ionos. The other is whether the smaller shape and smaller vents make the helmet more aerodynamic. While we've only worn the Prolight on one 90-degree day thusfar, it's pretty clear from all climatic conditions that the Prolight doesn't allow as much air to flow through the helmet as the Ionos. Yes, there are 25 vents and yes the interior has Wind Tunnel technology (aka internal exhaust channels), but the Ionos has much bigger vents and channels. But not measuring up to the Ionos isn't that much of a surprise; in our experience, no other helmet allows as much air flow as the Ionos.
In terms of cooling prowess, we'd put the Prolight about on par with our Bell Sweep R. As you can see from looking at Giro-sponsored ProTour teams, riders seem to be leaning toward the Ionos over the Prolight, which is striking when most seem to worry about shaving grams in most places on their bike save their saddle. Maybe that says something; comfort for one's brain and one's bum over-rides (so to speak) all other performance issues.
The size of vents brings up an issue near and dear to those who love perfect fit. Sticking sunglass temples into the helmet and having them look good and hang tight. Those who love sunglass temples fitting perfectly into vents will be a bit disappointed, but they still fit in, though not as perfectly as they do on the Ionos and Sweep R.
In terms of aerodynamics, there seems to be general agreement that helmets with smaller silhouettes should be more aero. This would suggest that the Prolight would be faster. However, the pro preference for the Ionos and team RadioShack going universally for the Ionos suggests otherwise. We take RadioShack's preferences fairly seriously as the team has access to as much wind-tunnel time as they need and it seems like performance director Allen Lim convinced his Lanceness that aero jerseys are the smart choice over the looser-fitting tops he was partial to in years gone by. No more flapping sleeves on this team. On the flip side are whole coolness equals performance theories.
We're probably thinking too much about the venting capabilities and splitting hairs whether excellent venting in an incredibly light helmet is insufficient when compared to incredible venting in a somewhat light helmet. Unless you're doing long climbs at high intensities on 90+ degree days, this obsession probably doesn't matter to you.
The helmet fits, the helmet is comfortable, and it's much lighter than anything else out there. Giro has another winner. After years of helmet weights inching upward, this is a big step back to light. What we're interested to see is when some of the weight-saving tricks start filtering into other helmets.