Mountain Biking light help

23 posts / 0 new
Last post
MikR
Offline
Last seen: 3 weeks 1 day ago
Joined: 09/28/2021 - 19:27
Posts: 3
Mountain Biking light help

Hi,
I’m looking for a light for my mountain bike for night trail riding.
I already have a Convoy S2+ sst40 that I’ll use as a helmet light.
I need a light that is fairly floody and can sustain 800-1000 lumens for at least an hour, probably a 21700 light. I have a bunch of low capacity 18650 cells (from a Dyson vacuum) that I’ll bring with me as backup.
Some options I’ve thought about:
Sofirn sp33v3 – looks nice but reviews say the thermal regulation makes it bounce between ~400 and ~1000 lumens, I need something stable.

IF25A – according to reviews it can only sustain around 500 lumens.

S21A – can keep constant 800-900 lumens for almost 2 hours with the SST40 emitter, maybe I should get it with a TIR/STRIP lens? Maybe even 2 of them? (though charging 3 batteries before a ride is annoying)

M21B gt fc40 – runtime and output looks good, the high CRI should be very nice for riding, but I’m not sure it’s floody enough.

Astrolux EC01/03- Some people in my area ride with them, not sure what’s the sustained output, and it’s only available at 6500K and kind of pricey compared to the other lights (and doesn’t come with a battery).

I would love your help, It’s great that there are so many options but it’s pretty overwhelming Smile
Thanks!

Forsythe P. Jones
Offline
Last seen: 1 week 6 days ago
Joined: 08/15/2021 - 00:40
Posts: 413
Location: California

Quote:
I need a light that is fairly floody and can sustain 800-1000 lumens for at least an hour, probably a 21700 light.
This might not exist because of thermal limits, though if the bike is moving then the airflow might help keep the light cool. Is a D4Sv2 a possibility? It is built for a 26650 so will have a little higher capacity and more thermal mass than a 21700 light.

800-900 lumens is really pretty bright. An old-fashioned car headlamp was around 500, I think. Come to think of it, maybe if you were using handlebar mounts, you could deal with the thermal and runtime issues at the expense of some weight by using two lights, one on each side of the handlebars. That could help people see you too.

Correllux
Correllux's picture
Offline
Last seen: 1 hour 24 min ago
Joined: 04/27/2019 - 22:23
Posts: 523
Location: USA

List of threads for bike lights with one pretty recent: https://budgetlightforum.com/search?q_as=Mountain%20Biking%20light%20

But first of all, what sort of riding are you doing? Speeds, width of trail, terrain type, lots of straightaway vs. lots of hairpins, etc.

I ride with just a helmet mount usually, so that can soften detail and shadows that can be helpful at times, but it works for me and I can ride as fast at night as I can in the day on trails that I know well. I’d suggest no less than 1000 legit lumens if you ride fast and/or are on narrow trails that aren’t groomed/easy. Adding a bar light to the helmet light is a good combo if you don’t mind the added weight and such…probably would opt for the helmet to be brighter than the bar, personally.

Honestly there aren’t any flashlights that I would want to ride with for my preferences and style of riding. My main light now is a Dinotte…..triple emitter housing with remote pack, tucks nicely into the camelbak. The housing is lightweight and rugged but I wouldn’t want to go back to a heavier light on the helmet, even something like an S2 feels kinda weighty up there and will tend to make the helmet shift around (with straps adjusted correctly). Some lights I had in the past that were heavier were just irritating but a couple times turned out to be almost a hazard when landing or riding baby heads caused it to shift enough.

Think carefully about hazards in a crash, too (mount type, cables, whether a tube light on top will be able to catch on something and wrench your neck…stuff like that isn’t important until it is).

I can think of a few flashlights that give the light and run time but none that aren’t way heavier than anyone would want, even on the bar. If it’s just easy pedaling on tame trails, about anything will work ok if you’re happy with the output.

Forsythe P. Jones
Offline
Last seen: 1 week 6 days ago
Joined: 08/15/2021 - 00:40
Posts: 413
Location: California

Back when I was biking at night much (on roads, not trails), powerful led lights weren’t a thing and I got by on the typical 10 lumen or so incandescent handlebar lights that everyone used then. I can understand trail biking being more demanding, but even still, if you want really good lighting why not go in the daytime? Flashlights are great but nighttime darkness is also great. We shouldn’t try to eliminate the dark, despite the logos of some flashlight makers ;). Use enough lumens to see what you need to see.

Correllux
Correllux's picture
Offline
Last seen: 1 hour 24 min ago
Joined: 04/27/2019 - 22:23
Posts: 523
Location: USA
Forsythe P. Jones wrote:
Back when I was biking at night much (on roads, not trails), powerful led lights weren’t a thing and I got by on the typical 10 lumen or so incandescent handlebar lights that everyone used then. I can understand trail biking being more demanding, but even still, if you want really good lighting why not go in the daytime? Flashlights are great but nighttime darkness is also great. We shouldn’t try to eliminate the dark, despite the logos of some flashlight makers ;). Use enough lumens to see what you need to see.

Why make a flashlight with more than 30 lumens then? Ooops…that’s Maglite and alkalines…which they still sell! Smile

I started out with I think 7w lead acid halogens and then the bump to 12w was incredible. Those were the days.

If you do mountain biking on narrow singletrack or trails that twist tightly in the trees or that’s overgrown, has rocky sections that aren’t just open slabs of rock, deadfall, etc…you’ll appreciate the light. And you can run them on lower settings if you like. Actually riding by moonlight is a blast, on some trails.

YuvalS
YuvalS's picture
Online
Last seen: 4 min 18 sec ago
Joined: 09/26/2018 - 10:39
Posts: 477

Forsythe P. Jones wrote:
Quote:
I need a light that is fairly floody and can sustain 800-1000 lumens for at least an hour, probably a 21700 light.
This might not exist because of thermal limits.

Yes thermal protection will decrease output after about  1-2 min 

I have just build a biking light for a friend based on an Aliexpess bike light with great cooling. it is not floody al also 12V xhp 70 but you can replace the emiter to a 3v and change optics..
Motorcycle LED Headlight from Aliexpress for bicycle night rides | BudgetLightForum.com 

My FW repository

My BLF/OL contest entries: 7th 8th 9th 

MikR
Offline
Last seen: 3 weeks 1 day ago
Joined: 09/28/2021 - 19:27
Posts: 3

Forsythe P. Jones wrote:
-This might not exist because of thermal limits, though if the bike is moving then the airflow might help keep the light cool. Is a D4Sv2 a possibility?.

-An old-fashioned car headlamp was around 500, I think.

-Well this review of the S21A says it stays at 800-900 with a fan cooling it, the M21B is similar. The D4Sv2 looks quite nice but also pricey, $55 plus another $20 or so for a battery (shipping is expensive for batteries), I can buy 3 S21A (with a battery included) for that price.

-A quick search tells me standard car halogen bulbs are around 1500lm per bulb

Correllux wrote:

But first of all, what sort of riding are you doing? Speeds, width of trail, terrain type, lots of straightaway vs. lots of hairpins, etc.

I ride with just a helmet mount usually, so that can soften detail and shadows that can be helpful at times, but it works for me and I can ride as fast at night as I can in the day on trails that I know well. I'd suggest no less than 1000 legit lumens if you ride fast and/or are on narrow trails that aren't groomed/easy. Adding a bar light to the helmet light is a good combo if you don't mind the added weight and such...probably would opt for the helmet to be brighter than the bar, personally.

Honestly there aren't any flashlights that I would want to ride with for my preferences and style of riding. My main light now is a Dinotte.....triple emitter housing with remote pack, tucks nicely into the camelbak. The housing is lightweight and rugged but I wouldn't want to go back to a heavier light on the helmet, even something like an S2 feels kinda weighty up there and will tend to make the helmet shift around (with straps adjusted correctly).

Thanks, My local trails are narrow twisty singletracks, wooded and rocky but nothing crazy, the fastest descents are around 20mph but I'm not going to reach that speed on night rides. I never tried night riding so I don't want to spend too much right now and bike specific lights are very pricey. I looked at the Dinotte light you mentioned and it's 100gr compared to 122gr for my S2+, not a huge difference.  

Forsythe P. Jones wrote:
if you want really good lighting why not go in the daytime?

During winter the sun sets before 5pm, it's not always possible to finish a ride before that. And I heard night riding is super fun.

YuvalS wrote:
I have just build a biking light for a friend based on an Aliexpess bike light with great cooling.

Nice light but I'd like something that has adjustment levels and doesn't require DIY work. Plus flashlights can be used as, well, flashlights when not on the bike. BTW I'm pretty sure I've seen you post this light on the "Moshe lumens" facebook group Smile

 

So I'm pretty sure the S21A (or maybe two of them) is a good option, Simon sells lenses to make the beam more similar to "real" mtb lights, it can keep 800lm for an hour and a half and it's very cheap ($25 with a battery). I'd love to more suggestions though. Thanks! 

MascaratumB
MascaratumB's picture
Offline
Last seen: 55 min 2 sec ago
Joined: 10/29/2016 - 12:12
Posts: 6877
Location: Portugal

Check the specs of the Xtar R30.

The first 10 minutes on Turbo on mine show “no” decrease.

I didn’t do tests any further but Zeroair has this graphics on his review:
https://zeroair.org/2021/08/02/xtar-r30-1200-flashlight-review/#Power_an...
TURBO

HIGH

elbakan1
Offline
Last seen: 1 day 23 hours ago
Joined: 12/05/2013 - 06:48
Posts: 356
Location: Miami Fl

Being a believer of Murphy’s law, and the theory that
Two is One, an one is none, I ride with 2 front lights.
Olights RN1500. They are dedicated bike lights.

Never need or use anything above medium.
These lights are a designed by Magicshine.
The mounts are similar to the GoPro. I’m sure they can sustain 500 lumens each
for at least 3 hrs. Maybe 4.
Way more than the rider can.

Cheers.

Lighting up the world one flashlight at a time.

EasyB
Offline
Last seen: 16 hours 51 min ago
Joined: 03/09/2016 - 15:24
Posts: 2189
Location: Ohio

I am also using “regular” flashlights for night mountain biking. Similar to you, I am using
approximately 1 hour or 2 hour runtime brightness modes. See below for my setup, as an example.

https://budgetlightforum.com/node/72989

In my experience the helmet light is the more important one. Your S2+ with SST40 will work, but I would want more throw, like a dedomed SST40 or SFT40 in an S2+. The required throw depends on your expected speeds, but I don’t live in a mountainous area and would still want more throw for those faster sections even if they are shorter. The S2+ is good for a helmet light since it’s light weight. I switched to a 21700 light, but am modifying my setup because it is a bit too heavy.

I think there are less stringent requirements for the handlebar light. It should have a smooth wider beam. Of course brighter is better, but the bar light is illuminating closer objects so it is not as critical for it to be very bright.

An important consideration is getting a light with the right modes. I have my lights setup for roughly 1hr and 2hr modes, but most lights will not come setup with good modes (for me). Often the high mode is too high and the medium mode is too low. I really like convoy’s “ramping” linear driver because it lets you precisely customize the modes. If you decide on a convoy light you might be able to have Simon install it for you.
https://budgetlightforum.com/node/71342

Regarding thermal limits. The breeze while riding provides a lot of cooling. Also, night riding often happens in the fall when temperatures are cooler.

Quote:
I can understand trail biking being more demanding, but even still, if you want really good lighting why not go in the daytime? Flashlights are great but nighttime darkness is also great. We shouldn’t try to eliminate the dark, despite the logos of some flashlight makers ;). Use enough lumens to see what you need to see.

LOL. What a buzzkill on a flashlight forum. Big Smile Nightriding in the woods is a lot of fun, and can be practical (like when it gets dark very early).

Correllux
Correllux's picture
Offline
Last seen: 1 hour 24 min ago
Joined: 04/27/2019 - 22:23
Posts: 523
Location: USA
EasyB wrote:
Nightriding in the woods is a lot of fun, and can be practical (like when it gets dark very early).

And before the spiders rebuild their webs….

Hank33
Hank33's picture
Offline
Last seen: 16 hours 51 min ago
Joined: 11/22/2019 - 16:00
Posts: 1373
Location: Vancouver, B.C.

I would assume the more the better especially for mountain biking. Sort of like what rally cars have but obviously downsized with our flashlight choices for 2 wheeler rides at night.laughing

Correllux
Correllux's picture
Offline
Last seen: 1 hour 24 min ago
Joined: 04/27/2019 - 22:23
Posts: 523
Location: USA
MikR wrote:
Thanks, My local trails are narrow twisty singletracks, wooded and rocky but nothing crazy, the fastest descents are around 20mph but I’m not going to reach that speed on night rides. I never tried night riding so I don’t want to spend too much right now and bike specific lights are very pricey. I looked at the Dinotte light you mentioned and it’s 100gr compared to 122gr for my S2+, not a huge difference.

I get that…and dedicated higher power bike lights are pricey (more than they should be, imho, always have been). I haven’t tried to keep up with the cheaper brands and such over the years but I wonder if Magicshine has anything decent these days or someone who picked up that ball. Their early ones weren’t so good really, but they were ok and certainly inexpensive. If MTBR still does their annual light roundup, that’s a great resource (even just past years’ reports are worth a look).

Not to niggle but I just weighed my Dinotte with the helmet strap mount and got 135g. My S2+ with a Sony VTC6 is 140g, so another probably +/- 60g for a mount. An ounce (28.35g) doesn’t sound like much but up top it feels like more weight, plus any leverage. Maybe not a deal killer for folks.

There are some flashlights like the Convoy M3 that will put out that much light sustainably for quite a long time, but not so suitable for riding (that one is large and beefy, uses a 26650 cell…plus a small issue that would totally rule it out for night riding). I don’t know of any compact ones that can deliver both qualities. If the riding isn’t so intense it’s not too much hassle to swap out a battery and you can tuck a couple in the pack easily (I’d keep them insulated and protected from any chance of denting in a crash, though).

EasyB
Offline
Last seen: 16 hours 51 min ago
Joined: 03/09/2016 - 15:24
Posts: 2189
Location: Ohio

Correllux wrote:

Not to niggle but I just weighed my Dinotte with the helmet strap mount and got 135g. My S2+ with a Sony VTC6 is 140g, so another probably +/- 60g for a mount. An ounce (28.35g) doesn’t sound like much but up top it feels like more weight, plus any leverage. Maybe not a deal killer for folks.

S2+ is about 70g without battery so should be around 120g with an 18650. Is your S2+ a triple?

If your helmet has the vents arranged so there is one in the center you can usually mount an S2+ very simply with a velcro strap.

Correllux
Correllux's picture
Offline
Last seen: 1 hour 24 min ago
Joined: 04/27/2019 - 22:23
Posts: 523
Location: USA

EasyB wrote:
Correllux wrote:

Not to niggle but I just weighed my Dinotte with the helmet strap mount and got 135g. My S2+ with a Sony VTC6 is 140g, so another probably +/- 60g for a mount. An ounce (28.35g) doesn’t sound like much but up top it feels like more weight, plus any leverage. Maybe not a deal killer for folks.

S2+ is about 70g without battery so should be around 120g with an 18650. Is your S2+ a triple?

If your helmet has the vents arranged so there is one in the center you can usually mount an S2+ very simply with a velcro strap.

Nope…but actually the one I weighed is a purple UV with the filter…can’t see that adding any weight vs stock, although the lens is a tad thicker maybe. I think mounting the light that way would be irritating (no adjustment) but sure. It could also encourage a split in a crash vs. breaking away or deflecting some of that impact. Back in the day before I plunked down money I hardly had for the early halogen lights, I taped two minimags to my helmet and attempted to have one on the bars…boy that sucked. lol. More exciting, though. Smile

I never used to think about “safety” like this, much less harp on it, but I’ve seen too much. Very odd things can happen in trail falls vs. typical pavement crashes, and you don’t even need to be going fast or on tough terrain. Very long time ago Bicycling magazine published a great tip-of-the-month: store your car key in your helmet using some velcro, and then it will never fall out of your shorts or jersey pocket. That was great, right, brilliant! Until that key becomes a harpoon into your noggin if you happen to crash and impact hard enough to crack the foam (doesn’t take much really, even with today’s better helmets). Along those lines, some of the “roadie style” helmets with rear projections that worked their way into the “mtb helmet” area pose some similar risks in off-pavement crashes and can accentuate head or neck injuries in the right circumstances.

jon7
Offline
Last seen: 3 weeks 4 days ago
Joined: 05/08/2017 - 19:56
Posts: 17

I trail ride at night as well. I’ve found that I need a very wide beam so I don’t crash when I’m cornering fast. I ended up with 2 S2+‘s in 2 Fenix mounts (https://www.fenixlighting.com/product/bike-mount-alb-10/). I have them angled slightly outward, which gives me a nice big oval of light. I’m sure a larger convoy light would work even better, but the key was getting 2 and using mounts that made it easy to angle them outward. I also have a smaller light on my helmet which helps.

Lightbringer
Lightbringer's picture
Offline
Last seen: 9 hours 33 min ago
Joined: 08/30/2016 - 14:12
Posts: 15735
Location: nyc

Hank33 wrote:
I would assume the more the better especially for mountain biking. Sort of like what rally cars have but obviously downsized with our flashlight choices for 2 wheeler rides at night.

“Hey, you leave the parking brake on or something?”

“Naw, that’s just alternator drag…”

09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0

whokilledJR
Offline
Last seen: 23 min 46 sec ago
Joined: 06/03/2012 - 13:05
Posts: 734
Location: Vietnam

There’s certainly no shortage of options. With good airflow you’d likely find output would be much more stable on the Sofirn sp33v3 and the light variance wouldn’t be perceptable. I’d definitely consider warmer neutral light tints as well for improved depth perception.

The recent TS21 appears (with proper temperature calibration) to hold in excess of 1000 lumens (from Lumen Maniacs recent review) which is a 27000 light.

A ton of convoy lights, the S2+ also has options with TIR optics that can flatten and widen your beam profile which is excellent for nightriding.

If you’re willing to go premium, thrunite has some excellent options with excellent sustained output, such as the TC20 or T2 and come with neutral white.

There’s no shortage of dedicated bike lights out there as well, including budget friendly. The nightriding forum at MTBR.com is an excellent source.

Any flashlight with an XHP70.2 emitter along with smallish reflector will give you high sustained lumens and a ton of flood, and look for lights that include neutral white as an option.

MikR
Offline
Last seen: 3 weeks 1 day ago
Joined: 09/28/2021 - 19:27
Posts: 3

Correllux wrote:

I get that…and dedicated higher power bike lights are pricey (more than they should be, imho, always have been). I haven’t tried to keep up with the cheaper brands and such over the years but I wonder if Magicshine has anything decent these days or someone who picked up that ball. Their early ones weren’t so good really, but they were ok and certainly inexpensive. If MTBR still does their annual light roundup, that’s a great resource (even just past years’ reports are worth a look).

Not to niggle but I just weighed my Dinotte with the helmet strap mount and got 135g. My S2+ with a Sony VTC6 is 140g, so another probably +/- 60g for a mount. An ounce (28.35g) doesn’t sound like much but up top it feels like more weight, plus any leverage. Maybe not a deal killer for folks.

I just can’t justify spending $80+ for a “real” bike light. There’s the new Astrolux BL02 bike light, it can output a constant 1100-1200lm for about an hour, 21700 cell, has a nice beam and is very cheap at 23 bucks, the performance is comparable to the Magicshine Allty1000 which is $85. But it has two issues- the UI is crap and the battery can’t be replaced, sucks if you run out of juice in the middle of a ride.

Just weighed my S2+ with the helmet mount (gopro mount+straps) and it weighs 166g, a bit heavier than a light with an external battery pack but as I said I ride with a hip pack so I have nowhere to put a battery pack (I really don’t like riding with a backpack).

whokilledJR wrote:
There’s certainly no shortage of options. With good airflow you’d likely find output would be much more stable on the Sofirn sp33v3 and the light variance wouldn’t be perceptable. I’d definitely consider warmer neutral light tints as well for improved depth perception. The recent TS21 appears (with proper temperature calibration) to hold in excess of 1000 lumens (from Lumen Maniacs recent review) which is a 27000 light.

Thanks, the TS21 looks quite nice, runtime seems better than the S21A and the beam is floody.
As for the SP33v3, I also think that airflow will improve its performance but unfortunately I can’t find a review that confirms it.

siata94
siata94's picture
Offline
Last seen: 3 days 15 hours ago
Joined: 05/13/2014 - 13:30
Posts: 458
Location: SoCal

depends on how rough and rowdy your trails are… I’ve shorted at least 2 lights, one didn’t even make it 50 yds down a rocky section.
After that I had lights built for me that are potted and no more issues.

samyy
Offline
Last seen: 2 weeks 6 days ago
Joined: 02/19/2018 - 14:06
Posts: 144
Location: PlanetEarth

Convoy M21D can sustain 1300LM for two hours.

icpart
Offline
Last seen: 55 min 35 sec ago
Joined: 04/15/2019 - 01:13
Posts: 334
Location: Bulgaria

If you need very powerful and very flood light Nightwatch NSX3 or NSX4 are that. For me best mountain bike light is my old Fenix BC30 which can sustain 1200lumens for over hour. My new favourite for biking are M21C and M21B with FC40. M21B 5000K FC40 have good balance between flood and throw. Also there is now M21B with XHP70.2 which will be also very floody. Best flood light which I have are NSX3 and Astrolux S43. For helmet light I think to try S21A with LH351D and TIR optic if I need more flood or throw.

story
Offline
Last seen: 4 hours 19 sec ago
Joined: 06/19/2021 - 18:22
Posts: 61
Location: Canada

I have experience with this. I used a D4SV2 W2 floody optics that’s giving me constant brightness and Anduril allows setting a higher temperature. I don’t like the W2 for biking because 5800k is not comfortable. I’ve switched to the Sofirn IF22A 4000k. This uses Anduril too so I set the temperature to 60c and it gives a very nice bright beam in high CRI. It’s USB-C rechargeable.

I tried the Sofirn IF22 (temp changing) and that’s not bright enough because of step down. I tried S2+ 219B 4500SW/3500SW and those are barely enough and I wouldn’t use it unless you are on familiar pavement road. However the 2 above are still better than 95% of what the biking community offers in terms of brightness.

- 900 lumens is needed because you are going fast and unlike cars which can absorb road impacts and water puddles. I also need other cars to notice me as if I am another car.

- You can 3D print a visor for it so the spill doesn’t blind cars and people opposite of you.