Kask Protone helmet – review

The Kask Protone is part of the next generation of aerodynamic helmets. Not a time trial helmet by any means but one designed for road riding and racing, and a lid which seeks to offer an aero advantage without compromising on comfort and ventilation. While we can't necessarily comment on the former, beyond Kask's claims, it is both very comfortable and well ventilated.

The Protone has been in the pipeline for a while. It was revealed just before the Tour de France, and appeared on the heads of a number of the Team Sky riders at the race, but only now is it available to the public. In the time since, the Protone has undergone a number of tweaks based on feedback from the team.

The Protone is one of six helmets in Kask’s road range, which starts with the entry-level Rapido and rises to the Infinity. The Infinity is the Italian firm’s full-blown aero road lid, and another which made its bow at the Tour de France, this time in 2013, and the Mojito is Kask’s all-purpose road lid, again used by Team Sky. The Protone essentially plugs the gap between the two.

Unlike the Infinity, which has a predominantly smooth surface save for a front vent which can be opened and closed, and rear exhaust ports, the Protone has something of a split personality. The front of the helmet looks like a normal road lid, with a number of large vents to suck in air, while the top is smooth. Out back there are six exhausts to provide an exit point for the air which has come in through the front of the helmet.

Kask say the Protone has been developed using Computational Fluid Dynamics software and wind tunnel testing, with the thinking that the smooth section confronts the wind when you head in angled on the bike. It’s not a full-on aero lid, like the Infinity, but one which seeks to balance some aero advantage with weight, ventilation and comfort, in a similar mould to the excellent Giro Synthe.

Out on the road and the eight front vents have to work fairly hard to suck in sufficient air to vent out of the six large exhaust holes carved smoothly into the back of the lid. It’s not exactly blowing a gale through there, but it is well vented and does a good job at keeping your head cool, and I have found myself reaching for the cottom cap in my back pocket more often than not when testing the Protone through the back-end of winter and early spring. As for any aero advantage, we don’t have our own wind tunnel here at RCUK (I’ve been asking for years) but, as a slither of anecdotal evidence (take it as just that), the Protone generates less wind noise around the ears than I normally experience with other, ‘non-aero’, road lids (handy when chatting on the club run).

Inside the helmet itself Kask have used two types of pad, again in a bid to improve ventilation and comfort. The front and lower pads are made from a breathable ‘Coolmax’ fabric, and they’re removeable and washable, while the padding at the top of the helmet is made from a perforated material dubbed ‘3D Dry’.

In terms of construction, the Protone uses what Kask call Multi In-Moulding Technology, whereby the polycarbonate cover for the top, base ring and back of the helmet’s shell is moulded to the inner polystyrene to reportedly improve the helmet’s shock absorption. Now, we didn’t take up the opportunity to crash test the Protone, but it does pass the EN1078 safety standard that you’d expect of any roadworthy helmet.

When you put the helmet on for the first time the most immediate feature you’ll notice is the ‘Octo Fit’ cradle at the back of your head. It’s impressively adjustable and extends far lower on your head than most other manufacturers designs, and wraps around the side of your head a little more. This gives you a noticeable feeling of being encompassed and enveloped by the helmet rather than it being perched on your head. The feeling of security is rather nice, and also removes any joggling of the helmet over rougher terrain. The actual polystyrene element of the helmet doesn’t extend remarkably lower than most other helmets, but the increased feeling of protection and secure fit are excellent features. The specific fit of a helmet can be very personal, our heads come in all different shapes and sizes, but I found the Protone to be very comfortable and I remained unaware of its presence on long rides, which is as good as you can ask for.

Continuing the theme, the ‘Eco-Leather’ strap is exceptionally comfortable. While it’s an area where the helmet is giving away a few grams of weight to its competitors (who, more than likely, use the normal webbing for the chin strap), in use it feels worthwhile. It’s simple to adjust, with a soft but robust strap, and adds to the overall quality of the helmet package. Speaking of weight, I weighed this medium Protone at 230g on the scales, which is right on the money against Kask’s claimed weight, and the same as the Giro Synthe. The Protone will slide an extra fiver out of your pocket but, all things considered, these are two well-matched aero road helmets.

The Protone comes with a simple textile bag for carrying the helmet in your race bag without the glossy surface becoming scratched. The Protone comes in no less than 12 colours and, while style is subjective, this black and lime test model received a lot of admiring glances.


All in all, the Kask Protone is a highly-adjustable, secure and well-ventilated helmet, with a number of carefully considered features for riders in search of a lid which offers a claimed aero advantage without compromising on comfort.

Newsletter Terms & Conditions

Please enter your email so we can keep you updated with news, features and the latest offers. If you are not interested you can unsubscribe at any time. We will never sell your data and you'll only get messages from us and our partners whose products and services we think you'll enjoy.

Read our full Privacy Policy as well as Terms & Conditions.