How many lumens does one need?

[ChrisV]

I have been looking at the Lezyne Macro (300 lumens) and the Super (500 lumens) and am now not sure about what I need.

My commute will take in some unlit cycle paths and roads and I will be going right through the winter - will I notice a difference between 300 and 500?

 

[fossyant]

You will have more output, but lit roads, you really don't want more than maybe 100 lumens - i.e. run the light at low on road. I have two original Hope Vision One's, they run at about 240 maximum, but I run then at level 2 of four. At max, both are enough for pitch black riding at over 20 mph. 2 x 240 isn't like 480, it's just better spread of light.

I have a selection of chinese lights that kick out 600 plus lumens (real lumens) and they are too bright for road riding - they will hiss off drivers. You run these low on lit roads.

Either choice will be fine for road use - If you plan some off road, get the reserve extra lumens. More is better off road, but on road, keep the power down.

 

[HovR]

You'll notice a difference - it won't be huge, bit it'll be there. I'd personally get the 500 lumen - you can always choose a dimmer setting, but if you pick the 300 and want brighter, you're out of luck!

Here's a torch comparison video showing the difference between a 350 lumen and 500 lumen torch. Click the link or skip ahead to 30:20.


View: https://www.youtube.com/watch?v=eXQV9doiaTE#t=1820

 

[ChrisV]

The guy in the video said there wasn't much difference to the naked eye between the two?

 

[HovR]

The guy in the video said there wasn't much difference to the naked eye between the two?

Still a difference, though. Keep in mind the guy in the video isn't travelling at 20mph dodging pot-holes! The difference is similar to the medium and high mode on my light. They're both stinking bright, and the difference isn't that great, but I'm glad for the extra brightness on fast downhill sections.

If going for the lower lumen light will save you a decent chunk of money then go for that, and in reality it'll be enough, but I think there'd be times I'd find myself wishing I had that little bit more.

 

[ChrisV]

Good point. Can get the Macro front and Micro rear for £50 new. The Super is £60 but I'd still need a rear light. So £50 for both seems a good deal?

 

[Maylian]

I've got both a 300 and a 500 Moon light for my carbon bike as they use the same mount (500 is a few years old). Both are easily suitable for dimmer roads, as many will say however when cycling on pitch black roads the 500 is just a bit better in picking out potholes and hazards when you're going at speed.

I think HovR hit the nail on the head and go for the extra and just use a dimmer mode when in built up / busy areas.

 

[Soup890]

That's a good question. I always thought the brighter the better.

 

[ChrisV]

Now I'm down to a Macro/Micro set for £50 (front 350 lms)

... or the Super Drive XL on front (500 lumens) and Micro on rear for a grand total of £83.

It's a dear game this, made worse by the fact I keep opting for the expensive option!

 

[ufkacbln]

The problem with bike lights is NOT the brightness, but the failure of the companies to design road lights.

Car headlights have a "shaped beam", that allows brightness, but because the beam has no "top half" it does not blind in the same way that a bicycle light with a full round beam and the same intensity will do.

What we need really is lights that reflect this and allow sensible beam patterns with adequate brightness

 

[mattobrien]

I have got an exposure Axis, which is stated to be 550 lumens. Running it on medium is fine for unlit roads and will last for 6 hours. Full power is far more than I need for on road activity.

 

[potsy]

You will have more output, but lit roads, you really don't want more than maybe 10,000 lumens

I'd be tempted to go for the 500 just for the extra power when needed, or maybe 2 of the lower powered ones

 

[moo]

The problem with bike lights is NOT the brightness, but the failure of the companies to design road lights.

Car headlights have a "shaped beam", that allows brightness, but because the beam has no "top half" it does not blind in the same way that a bicycle light with a full round beam and the same intensity will do.

What we need really is lights that reflect this and allow sensible beam patterns with adequate brightness

I run 2 B&M Ixon Premium lights that have a shaped beam. After the first 30 minutes with battery voltage normalised, lumen output is less than 150 for each. However, because the light is all going onto the road they do a better job than my 2400 claimed (900 actual) lumen Chinese CREE light. More brightness from a single unit would be nice tho, which is why I have 2 of them.

 

[ufkacbln]

There is also the issue where "dipped" does not mean lowering the power, there is also a change in beam pattern as well

 

[Wobblers]

It's not just the number of lumens, it's the beam shape which determines where those lumens go. I often run a Magicshine MJ838 with a Philips Saferide 80. On paper, the Magcshine's brighter (350+ lumens versus 270). The Philips appears brighter, and lights up more of the road because it shapes the beam into something close to the dipped beam pattern you get on a car, so most of the light goes into lighting up the road in front of you rather than into the eyes of oncoming motorists that most bike lights manage to do. 300 lumens in a dipped beam is more than enough for fast descents. You need far more if you've got a conventional conical beam shape.