Some aero helmets can leave you in a hot sweaty mess the moment
the mercury or gradient shoots up. Kask has produced a helmet that
doesn't compromise ventilation in the pursuit of aerodynamics.
We've tested it over hours of riding in different climates and
scenarios, and can confidently say it keeps you cooler than most
other aero helmets. At high speeds the large front vents noticeably
pull in buckets of cooling air to reduce heat buildup, making it a
great choice for road racing. During long mountain climbs we
noticed less heat buildup wearing the Protone than other helmets
too, ideal for tackling the Marmotte or L'Etape du Tour.
It's all very well having the lightest, most aerodynamically
efficient and highly ventilated helmet if it isn't comfortable.
Fortunately, Kask ensured the comfort of the Protone is equal to
its performance in other departments. The result, it's one of the
most comfortable helmets we've used. The comfort is aided by
generously cushioned pads where the helmet contacts the scalp. The
retention system (Octo Fit Kask calls it) is smartly designed and
can be adjusted vertically which means you can get the two large
cradling brackets to comfortably snug the back of your head. A
small rotary dial permits easy adjustment on the move but I found
the fit of the helmet so good and the retention system well placed
so only a few turns of the dial were needed to keep the helmet from
The side straps continue the comfort theme. They're thin and
narrow and soft next to the skin, and a synthetic leather chin
strap ups the comfort furthermore. We like that the buckle is
positioned off-centre alongside your face rather than right under
your chin. There's no irritation from straps when you're 6-hours
into a sweaty gruelling ride. The Protone does the best job of
virtually disappearing once you've clipped it into place. Ensuring
it's a suitable helmet for everyday use, the padding can be easily
removed and washed.