The new range-topping Dharma helmet, from Spanish kit manufacturer Spiuk, promises tremendous performance-per-pound potential. It comes in two sizes, S/M (51-56cm) and M/L (53-61cm), and nine colour options, with an alternative set of anti-insect mesh pads and a soft microfibre bag.
It also has a clip-on aero shell. On top of 20 sizeable vents, Spiuk supplies a removable, completely enclosed shell that mirrors the helmet's shape – just without the vents. Our M/L sized helmet weighed a respectable 274g, and the aero shell added a mere 44g more.
Spiuk's W-FIT 82 rear retention system has three height positions, and an easy to use wheel for simple on-the-fly adjustments. We were impressed with the Dharma's compact external dimensions; our tester was close to the upper limit of our helmet's size range, and the internal shaping suited his fairly round head perfectly.
Key to the Dharma's low bulk construction is its Supercage design. Its polyamide and ABS internal shell offers great rigidity and allows for larger vents. This is surrounded by a softer dual-density foam next to your head for greater impact absorption. The external shell comprises several sections, said to increase impact safety, and is neatly in-moulded for strength and durability.
The Dharma felt instantly comfortable, low enough at the temples, firmly retained at the rear with enough room for a cap. Venting without the shell was on a par with most comparable helmets, channelling cooling air over your head.
The aero shell has several advantages – notably its hard-to-quantify drag reduction. But one vent above each temple neatly remains open, helping to push hot air out of the uncovered rear vents, and making the shell almost imperceptible – until it rains, when you'll appreciate a dry, warm head.