Garmin Varia UT800 Smart Headlight review: clever light adjusts its brightness automatically

Garmin Varia UT800 Smart Headlight review in a sentence: a high-powered bike light that isn't so smart without a connected Garmin bike computer.

The Garmin Varia UT800 made our list of the best bike lights purely because it felt like the first front bike light that had been designed with performance in mind. Rather than awkwardly sitting atop the handlebars, it comes with numerous mounts for helmets and bike computer mounts, meaning it's easy to get a set-up that's as sleek as your carbon or steel framed road bike.

On top of this, the light packs some seriously clever tech, automatically adjusting its brightness depending on the ambient lighting conditions and even adjusting lumen output depending on speed.

The latter feature only works if you have it paired to a Garmin computer, but it's possible to have full control over the light without an Edge, you simply hit the button like any old analogue front lamp.

Garmin Varia UT800: price and availability

The Garmin Varia UT800 costs £149.99 when purchased directly from Garmin's site. But it can be found cheaper elsewhere, like Amazon UK, where it's £86.78.

Garmin Varia UT800 review: design and features 

It is difficult to get properly excited about a front bike light, but the compact proportions of the Garmin Varia UT800 fit a road bike's slender cockpit neatly and sits nicely on the beefier front end of a mountain bike.

This is particularly true if you own some of Garmin's existing products, such as its bike computers. Here, you'll find a cool "out-front" mount house a bike computer but also doubles up as a place to hang the light from underneath, placing it bang centre in a standard road bike's handlebar setup and tucking it neatly out of the way.

Most of the bodywork is fashioned from toughened plastics, but there are also reinforced areas around the rear of the light and the front lens. It looks good and certainly feels more premium in the hand than many rivals at this price point.

As front lights go, it sits around mid-to-top table in terms of overall brightness. There are lamps that pump out a frankly ridiculous 1800+ lumens, making the Garmin's 800 seem a bit meek, but it's not really the case when out on the bike.

The highest constant setting delivers a fairly wide beam that's enough to light up dark roads ahead. Garmin claims it is also visible in daylight from more than 1 mile away.

In terms of features, it cleverly selects the correct amount of light to emit depending on the ambient lighting situation. This, according to Garmin, helps saves precious battery life and means you don't have to cycle through the various modes when on the road.

Pair it with a Garmin computer and it gets even smarter, pumping out more light when you are travelling at greater speeds, and conserving energy by dimming the lights as you slow. But it's not 100 percent perfect...

Garmin Varia UT800 review: performance

Many other front bike lights opt for a silicone strap and loop fastening system, which is fine for quickly slinging a light around any old bars, but can often look a bit slapdash on quality bikes. 

Garmin's "out-front" mount might be a tad overkill, but it feels aesthetically worth it for the minute or so it takes to quickly attach one. That said, Garmin's mount won't fit the flat carbon fibre cockpits found on today's top-end road bikes, meaning you'll have to find one especially for this application. 

Charging seems to take an age, but you apparently get 25 hours of light on its lowest setting or a more realistic 6 hours on Day Flash mode. However, I did find the batteries drained pretty quick when on the highest constant setting. Again, official figures are pegged at 1.5 hours, but it felt like it only just about managed an hour's worth of commuting before I had to plug it in.

But worse still, the light also drains its batteries surprisingly quickly when using all of its smartest features. So those that are supposed to conserve energy actually only buy you a little more time than leaving it on its highest constant setting. 

It's a shame, because the Garmin Varia UT800 reacts quickly to changes in ambient lighting and works really well when an Edge computer is paired for speed read-outs. Get up to a fast pace on a dark country road and the unit will give full beam, but hit a steep climb or head back towards civilisation and it will start to dim without you really realising it. Irritating that it doesn't really conserve battery though. 

The light spread and quality isn't the greatest compared to other 800 lumen rivals. It could do with being a little wider to light up more of the road, but it's not a huge deal. It's sill plenty bright enough for most use cases. 

Another slight bugbear is with the "out-front" mount itself, which is a bit bulkier than other Garmin mounts and doesn't tighten up to give a perfect, rattle-free fit.

Garmin Varia UT800 review: verdict

The Garmin Varia UT800 is one of the best looking front lights you can buy and it sits really nicely on lithe carbon road bikes, where maintaining some sort of aero upper hand is tantamount to many owners.

Battery life is generally good, but when using all of its smartest features (and probably the main reasons you bought the light in the first place) it eats into battery life to the point that rides over 2.5 hours could leave you in the dark.

Weirdly, it's at its best when left to manually cycle through the different lighting modes when out on the bike. It's neat, provides a good quality of light and even works well during daylight hours, where the flash mode is bright enough to drastically improve visibility. A great light, just not a perfect one. 

Garmin Varia UT800 review: also consider

The Beryl Laserlight Core combines a standard, max 400-lumen LED light with a green laser, which beams the image of a bike about 2m in front of you as you ride. This alerts other road users to your presence more effectively than a light alone. This super light bike front light is somewhat cheaper than the Garmin Varia UT800 too.

If you're after some heavy duty lights, look no further than the Exposure Strada SL: it has a maximum output of 900 lumens, which is comfortably bright enough to light the way on dark country lanes. In fact, for most riders, this is all the light you’ll ever need. This light is a bit on the pricey side, mind.