Exposure's new Diablo should be an ideal helmet-mounted companion to their impressive range of bar-mounted lamps – but it needs a more tightly focused beam to maximise its usefulness on the trail.
As a higher-powered offshoot of the popular Joystick, the Diablo offers a much brighter 700-lumen claimed output (versus the Joystick's modest 240 lumens), a similarly tidy (albeit bigger) all-in-one cable-free casing, a barely-there 103g weight and Exposure's clever Smart Port Technology that lets users add accessories like battery packs and rear lights.
But that promising 700-lumen output is dampened by a beam pattern that's too diffuse and doesn't provide enough long-distance punch for seeing further up the trail or around corners when traveling at reasonably high speed (for this application Exposure's more tightly focused Joystick might be a better option).
Especially when combined with a high-powered handlebar light like Exposure's own MaXx-D, the Diablo beam washes out and it's hard to discern trail features that aren't directly in front of you. The lack of long-range reach also limits the Diablo's usefulness for road rides – especially if there's some of ambient light from street lights – save for more moderately paced commutes.
During our final test session during the 24 Hours of Moab, we had to back off the speed considerably on high-speed sections lest we overrun our field of view and we even managed to veer slightly off course in a few spots because we couldn't see far enough ahead at race pace.
Run time is very short, too. Though we regularly got longer burns from the on-board lithium-ion battery than Exposure's claimed one-hour on the 'MaXx' setting (burn time on 'high' is a more reasonable three hours minimum), most riders will want more juice to get through typical night-time jaunts in the forest.
To Exposure's credit, those riders can easily more than double – or triple – the figure by plugging a one- or three-cell piggyback battery into the rear accessory port but we'd rather that extra cell be included as stock to begin with.
On the plus side, construction quality is superb, as we've come to expect from Exposure. The housing is made of sturdy machined aluminium with integrated cooling fins up front, laser-etched markings outline key features such as run time and basic button operation, and O-rings keep the entire unit shielded from mud and water.
Likewise, the included helmet and bar mounts are well designed. The former easily attaches to just about anything with vents (we tried six different lids) and the surprisingly stable ball-joint cradle makes for mind numbingly easy aiming – just grab the Diablo and turn it until the beam is in the desired location and it'll stay there no matter how rigorous the jarring.
The bar mount is a more conventional bolt-on pivoting aluminium clamp and can only be adjusted up and down (there's no left-right aiming ability) but it's rattle-free and takes up minimal space.
Used on its own, the Diablo does a good job of illuminating the way as long as you aren't going too fast or are out for too long (lest you use the aforementioned piggybacks, that is). However, it needs a more tightly focused beam to work well as a supplemental helmet light. The price is reasonable, considering the total light output.