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Cateye Volt 400 Duplex Helmet Light review

4 Oct 2017

Integrated front and back helmet light with a robust lumen count and battery

Cyclist Rating: 
Neat and bright
Not much but you can find more lumens for less cash

Lighting technology has been racing ahead in recent years, meaning brighter, lighter and longer lasting models at lower prices. The Cateye Volt 400 Duplex is a svelte helmet-mounted front and back combo light that would have cost a lot more only a couple of years ago.

Providing forward illumination along with a rearguard back light, when attached to the helmet the Volt sails above the level of bike-mounted alternatives, making it unlikely to get obscured in traffic.

For use in unlit area it also has the advantage of allowing the rider to turn their head in order to direct the light where it’s most needed.

This is particularly useful when cornering, a situation where handlebar mounted lights often fail to keep pace with the rider’s changing trajectory.

It also makes the Cateye Volt 400 Duplex Helmet Light ideal for giving drivers a high-beam death stare if they stray into your lane while also letting you indicate that you’re giving way with a sideways nod.

Strapped to the top of the helmet at 110 grams its weight is just about noticeable on your head and may cause your helmet to wobble slightly.

That said I never found it irritating and dialling down the retention is enough to counteract any additional slippage.

On road the 400 lumens the Volt provides is the more than enough for commuting, and just about enough for riding without the additional illumination of street lighting.

However my preference would be to use a brighter lamp if navigating back country lanes. In this situation the Volt makes a fantastic additional source of illumination, evening out shadows and allowing riders to spotlight particular areas.

Out back the rear light only provides 10 lumens. This might seem a scant amount yet in reality it’s easily enough to pick the rider out among the jumble of city traffic or at a distance that makes it safe for use on quieter roads.

Regardless of terrain, it’s worth noting that current legislation means technically you’re still required to have lights fixed to your bicycle when out riding, although in reality using the Volt on its own is unlikely to cause you problems.

Getting cyclists to use lights during daylight hours is either a brilliant idea or a superb marketing wheeze.

Certainly it removes one further excuse for other road users to miss seeing you. Unsurprisingly Cateye are onboard, and the Volt 400 Duplex is easily punchy enough to serve as a daytime running light.

Construction and operation

The lens unit includes the switch while the battery unit screws securely into the back. This in turn houses the fixed rear light. Up front a lens focuses the light output without hotspots.

Protruding backwards from the main body the rear light provides a commendable amount of side-on visibility.

An absolute necessity for UK use the all-weather construction is pleasingly robust. Previous experience of Cateye lights also suggests durability will be good, as is the availability of spares.

A long press turns the light on and off. Never leaving the rider in the dark, once on pressing again cycles through each mode without ever turning the light off.

Cleverly the light also remembers the mode in which it was last used and returns to it when first turned on.

The helmet mount itself allows you to adjust the angle at which the light sits and is commendably solid.

However it does gel better with some helmet designs that others, sitting more prettily on models with a central spar running down the centre.

Consequently it fitted better on a Lazer Z1 helmet than it did to a Giro Synthe.

Supplied with just a helmet mount the Volt will also fit the brand’s standard handlebar fixings, although doing so will obviously render the rear light redundant.

Charging via a micro USB port using this method it’ll take the Volt around six hours to achieve full charge.

Impatient users can opt for the extra Cateye USB 2 Way Charging Cradle. Costing £20 this not only cuts charge time by about a third but also allows you to use the light’s battery to power other gadget like mobile phones or GPS computers.

Teamed with an additional battery it’s likely to be of interest primarily to touring cyclists.

Once juiced up using the Volt on its most powerful 400 lumen setting will see a claimed burn time of three hours.

Switching down to 100 will expand battery life to 10, while the lowest setting of 50 lumens will push its lifespan to 18 hours.

The low power flashing mode will expand its use to a huge 150 hours.

Pleasingly, using our scientific ‘leave it on the desk until it goes flat’ test I found these estimates to be on the conservative side.

By comparison the rear lamp is able to run for 25 hours alone in its constant mode. Powered by the same battery its use will decrease the overall burn time of both lights.

However employ the flashing mode and it doesn't draw enough power to notably affect the runtimes for the front LED.

When the battery does finally get low the button on the top of the light glows red. Obviously when on your head this isn’t much use and it would have been nice if the light itself flashed occasionally to indicate the approaching end of its charge.

More cleverly the rear light will switch to flashing mode once the battery gets low in order to give you the longest possible window to get home safely.

A neatly integrated front and back light that strips accessories off your bike the Volt Duplex makes other systems look ungainly.

Backed up by a two year warranty assuming you’re happy to switch from bike to helmet mounted illumination the Cateye Volt 400 Duplex Helmet Light makes a great choice for both commuting and more adventurous uses.

For more information and to buy the light see:


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