The next PBP Randonneur (2027) has introduced mandatory helmets. I have been riding PBP since last century and much prefer a cotton cycling cap for long brevets in hot weather but that option no longer exists for PBP. Living in the UK, I am not heat-adapted and had to stop in the shade to cool down when temperatures climbed over 30C during PBP 2023.
Don’t bother with cycling helmet safety comments. I am not interested in unevidenced beliefs about reductions in deaths and serious injuries.
What cycle helmets will minimise heat build-up at low average speeds, ignoring other considerations? Think 25kph average, not 40+kph.
If you’re not fussed about its efficacy as a helmet, could you maybe try an old-school hairnet helmet? I don’t know if they would allow it, but that’s probably about as lightweight and ventilated as you’ll get.
Comfort is probably as big a factor as ventilation, and comfort can depend on if the shape of the helmet works with your head shape. You might need to try a few helmets on in a retail store to get a feel of what brands suit you. For what it’s worth I use a Bell XR Spherical helmet, for me it’s is super comfortable and it’s one of the best ventilated helmets out there. It’s not the cheapest, but I have seen it on sale lately at a price that is good for the quality and technology.
If you are saying that the interior temperature of a helmet made from insulation material (EPS) changes depending on the colour of the outside surface, that should be backed up with some hard numbers. That assertion fails the smell test.
I started racing at the tag-end of the leather hairnet era and started wearing hardshell helmets before they were made compulsory in Oz. A hairnet probably won’t cut it because nobody would recognise it as a helmet.
I am looking for a helmet that is cool at recreational climbing speeds, not pro speeds. Ideally recommendations more reliable than “This felt cooler than the two other helmets I’ve ever worn.” I suspect that head position, hair length and what sort of glasses you wear makes a difference in air flow through and over a helmet. Is somebody doing comparative helmet testing for temperature?
Some helmets claim ventilation benfits based on “channels” inside the helmet, where warm air is sucked out the back. In my personal experience, this ventilation is hard to achieve if you don’t have very short hair.
Instead, I went with the helmet with the largest holes, especially at the front, for my warm-weather climbing helmet.
AFAIK, the best you are going to get are anecdotes. I am unaware of any testing data re: the cooling effect of helmets.
The consensus seems to be that the Giro Ares, Specialized Prevail and POC Ventral Air have some of the best ventilation available. I have not ridden any of those, so can’t comment.
I would try a few different options mentioned above and try to think out how the sweat will channel down/out based on your riding.
I find the Prevail does a terrible job and everything just ends up in my eyes where the Procen Air seems to funnel sweat towards the back even while climbing a little more upright.
My choice for PBP 23 was the POC Ventral Lite, which is basically the same as the Ventral Air, but lighter. If you aren’t used to wearing a helmet on long distances, I’d value low weight as much or more than good ventilation. Adding an extra 200-300g to your head for 1200km without prior adaptation seems like it would dramatically increase the risk of Shermer’s Neck.
And for what it’s worth, even with a light, well-ventilated helmet, I also sought the refuge of some inviting trees and one blessed grocery store walk-in cooler during the heat of PBP in 2023. I don’t think not wearing a helmet would have made any difference.
Some Giro helmets have tab that extends forward from the front pad that allows sweat to drip off and not run into your eyes or drip onto your glasses. My Giro Ellipse Spherical with MIPS has this and it works well. I know there are other Giro helmets with the feature, I think it’s likely that some helmets from other brands might have something similar.
