Can anyone recommend a headlight?
I want it to attached underneath a Garmin out front mount - so either quarter turn or go pro compatible.
Must have excellent battery life and a good light beam.
I will primarily use this for road but could double up for trails. I would generally use it at dawn/dusk and therefore no night riding.
I don’t need ANT+ capabilities.
I have tried the Garmin UT800 but the battery life sucks. I am open to other options.
Cygolyte. I have a Metro and love it now that I mounted it under the Garmin out front mount.
I cludged together a Cygolite GoPro adapter to a Garmin out front underside mount to make it work. Very solid.
Not sure what your specific use case is but @ultrawolf, @mountainrunner, and others have talked about the importance of also having a helmet light.
My highest recommendation goes to Exposure Lights, but let me step back first.
I had a Light & Motion Trail light which worked well. However, its battery life dropped to 10-20min when the temp dropped below 10ºC / 50ºF. I then went to a Bontrager ION 800 RT which did handle the cold but during a long ride (Grinduro Dolomites) with literally hours of heavy rain, it failed. (Once it dried out, it worked again and now sits in a drawer.) The L&M may have been 1000 lumens and the Bontrager was 800 lumens.
I needed something more waterproof, could handle temps, and I wanted more battery life than either the L&M or the Bontrager, which, under ideal conditions, gave around 75min of decent light. And, ideally, something with more lumens. I often ride in the dark (pre-dawn, rarely after dusk) and sometimes ride through tunnels. (The bluetooth option of the Bontrager – and I think the L&M light, too, but I could be wrong – was cool for automatically turning on and off the light under thick shading and in tunnels but this feature takes energy.) Another requirement was compatibility with a GoPro mount, which both the L&M and Bontrager also had.
I landed on Exposure Lights, particularly the Mk 14 Race (which I guess was replaced by their Mk 15 Race). It has a digital read-out telling me battery percentage, an auto-dim if you stop / are still for a while, and a bunch of different light settings. I use just two settings: max & max-low (not their term).
The Mk14 is 2100 lumens (far greater than my previous lights; the Mk 15 is 2200) and the battery life is awesome. A typical pre-dawn ride of 75min on max has 67-71% of the battery remaining. Yesterday, because of dense fog so the occasional car on the occasional pavement I rode and for walkers / cyclists I might encounter on trails, I had the light on “max-low” (the low setting for Program 1, the max setting) for the 4hrs and the battery still had something like 70% left (it’s rated for 12-13 hours at that setting).
They have smaller and larger sizes, but this size fit me. The spread is great, the brightness and whiteness is perfect (things aren’t washed out), and the battery life is superb. The digital indicator on the back for battery life to indicate the setting is also great. Besides the digital read, there’s a green light for the max and red for the max-law, which is toggled between using the single, easy to access and use even with a thickly gloved finger. Also, temperature, even down to -15C, has not meaningfully impacted the battery life.
In the pics, you can see ExposureLights uses a little extension doo-hicky, which gives an additional adjustment option and, more importantly, means you remove the light simply by pulling up on the red disc.
I do have the light pointed slightly more downward than I would if I was only running this light. Because I’m often riding in pitch black, or nearly so, I also ride with a helmet-mounted light: Lupine Piko, 1900 lumens on high. After a year the battery is about barely 1hr at high so now I toggle to medium, the remote for the headlight is attached to the side of my K-Edge (see the first pic above), when possible & carry a second battery. I like to see not just where I am going (the bar-mounted light), but where I want to go or simply to the side (hence the helmet-mount). The combination gives me great sight. This gives me plenty of light to see a spider at mouth height and distance to see obstacles 
Of course having the two lights at different intensities helps reveal and not washout or hide trail contours as I like my technical stuff where shocks would really come in handy.
Again, my rec is to look at ExposureLights. Solid, great battery, great beam, etc. You also most likely want to look at a trail light, whether ExposureLights or otherwise, because trail / MTB lights are more likely to have a wider spread.
I’m looking for a decent quality front light that will attach to the underside of my Garmin/GoPro out front mount.
So far I have come up with something like this:
https://exposurelights.com/products/bike/mtb-lights/race-mk15-gmb
Coupled with this:
https://exposurelights.com/3prong-action-camera-to-exposure-cleat
Does anyone run a similar set up or could recommend a solution?
Thanks!
Exposure light household here!
I run two Stradas on different road bikes (good cut off beam to avoid blinding drivers, whilst not being STvZO it’s still pretty good).
I have a Revo on my winter hardtail, attached to an SP dynamo hub, and have a Race on the full sus for night riding. These are backed up with either a Joystick or Diablo (mounted on helmets). I also have a Link Plus for commuting (allows me to be seen rather than lighting up the road).
In terms of your use, I would probably recommend a Strada as the more trail oriented lights will blind oncoming traffic unless you point them right down. Pair it with a Diablo for great off-road lighting!
All of my lights are mounted upside down on the same mounts shown above or on the Exposure helmet mount.
Link Plus and Diablo helmet mounted.
Exposure GoPro mount on the underside of a Garmin mount.
Strada ready to use on the wife’s road bike.
Revo mounted with a non-QR mount on my hardtail (as the light is very rarely removed!)
Another vote for NiteRider Lumina….I have a 900 that has a boost to 1100 lumens if I need / want it and it just works. Also relatively cheap….can be found for less than $100.
I just bought this Serfas light in October and it is now even cheaper…$90. 1600 lumens for ~1.5 hours, or much longer at lower lumens (but still plenty of light). I have actually found that 1600 lumens is “too much” because it tends to flood out my helmet light (the NiteRider). 
Exposure lights are great, but I am not certain they are worth the price premium. But people who use them, love them.
I also have a Garmin Varia headlight…it is OK but the intensity of the light is a bit lacking vs. the NiteRider (same lumens).
ETA - both the NiteRider and Serfas lights can be used on GoPro mounts, but require a separate adapter. For the NiteRider, I recommend the K-Edge adapter…the stock NiteRider one tends to pop off.
I’m a huge fan of Gloworm lights out of New Zealand. Massive lumens, Gopro mount compatible and replaceable parts. If you don’t mind the external battery they are perfect.
I bought a Strada recently and I’m very disappointed. I have to have the light pointing right to the front of the tyre to don’t blind everyone else. I use the AKTIV function (auto cut of beam) but still blind cars and pedestrians otherwise.
It’s advertised as a road specific beam but the spread of the light is a perfect round beam?!?!?
Either I’m not getting it (please share any tips) or is a bunch of marketing BS
It’s a buy that I regret.
I have a couple of older Stradas, so not Reaktiv. Couldn’t comment on the newer ones but both of mine have a great cut off. Might be worth dropping an email to the guys at Exposure because they are super helpful 
Sounds more like a Race or one of the MTB lights by your description of the beam pattern!
I know they had plans to make their road lights obey the STvZO regulations but they seem to have dropped that at some point (Exposure Optic as an example).
Outbound Lighting’s road light is amazing. Blows away all the other lights I’ve ever used because it has a shaped housing similar to vehicles, long battery life and they have a 3D printed adapter so I can mount it under my Garmin https://www.outboundlighting.com/products/road-edition
Cheers for the reply. Ill get in touch with them.
When you say cut off you mean dim the light when facing an incoming car? This is the AKTIV function.
No, by cut off I mean the throw of the light is shaped to have a flat top - see here for what I mean:
Cheerios 
I’ve been using a lezyne 700 xl for a few years and very happy.
I’m based in Ireland and on unlit countryside roads you still have really good vision.
Loads of settings to choose from as well
I will also point out that my favourite lighting setup is on my Reilly Spectre - I have an SP dynamo attached to a B&M IQ-X (which can be rotated and mounted to an inverted GoPro mount).
I run the wires on the inside of the fork with some bar tape finishing tape and run the wires to the rear light internally with the rear mech wire.
It then means the lights are always on the bike and never need charging!
What battery life do you need? I have a cateye volt 700 which a full brightness is 2 hours of battery life. But if it’s not night riding it gives 10 hours at 100 lumens and 3.5 hours at its 300 lumens setting. If you’re only using at dawn/dusk with no night riding it doesn’t seem like you need anything with super long battery life
Another Exposure recommendation here. Don’t think it’s been mentioned so far but their models have several “programme modes” as well as high-medium-low so you can choose the one that gives you most illumination for the time you are expected to be out: a couple of weeks ago I did an all nighter (here in the UK that means darkness from 5pm to 7am) - prior to the ride I set the unit up to give me most light for that time. Actually I had my wife’s unit as a spare so they were both set up to give ten hours on medium. I got 9hrs30 out of mine before it died and I needed to swap.
I finally ordered one, 2000 lumen version that I’ll use as a helmet mount for trail riding. I was out riding my Outbound setup on fast downhills. Hoping this helps. 
I’ve sold lots of Exposure Lights and never had an unhappy customer. I personally have gone through a slew of other lights that I’ve only ever been unhappy with, and I probably could have bought several of Exposure’s nicer options with what I’ve spent on all that junk. One day I’ll bite the bullet and do it right. But consider this another vote in that direction. NiteRider would be my second choice, but their warranty support went off a cliff in the last couple years, so beware.
