Is it possible with the use of well placed electrical tape to achieve a STVZO type effect on bicycle front lights? In other words, cutting off the top of the beam so as to avoid dazzling oncoming traffic?

I have today taken delivery of a Moon Meteor Vortex front light. The lens has a cowl over the top and a cut away at the bottom, perhaps to try to achieve a dip. Unfortunately, I shall be using the light upside-down on a Moon/Garmin over-and-under out-front combo mount. Therefore, with the cut away it’s even more floody in an upwards direction. Will some black electrical tape over the cut away make any difference, or are the beam characteristics really all to do with the reflectors inside the light?

It’s really all the reflector.

The led is typically in the roof of the lamp then a reflector at about 45deg (not exactly and profiled obviously) bounces it up the road.

Its cleverer than just a cut off, the reflector gives an even illumination on the road from the front wheel into the distance, whereas just pointing it down gives you a hotspot up close and probably not a great cuttoff.

No, not really. At least not effectively. I’ve tried a few things, but the problem is that the glass is too far away from the LED. So you just end up blocking most of the light.

I doubt it. Spent most of the winter deliberating over a road light after taking delivery of a (faulty) Moon Meteor Dual which when I got to test the beam was very disappointing, ie not wide enough, is unfocused and floody/spotty.

After looking into DIYing a cutoff-shield on a few other light-geek threads on forums it didn’t seem a profitable or effective route so ended up coughing up another £10 extra for a Ravemen (PR900). Mini-review below.

It arrived just over a week ago and I have to say it’s literally ’night and day’ by comparison to any MTB light I’ve owned.

In short – very much like a motorcycle light. It has ‘dip’ with an appreciable cutoff, with a boost/main beam (which is also operable by a long press on the remote button o-ringed on the bar next to my brake lever)

The road/cutoff beam emitter is a really nice subtly warm/pale rose tint which makes green grass and trees look natural and not the sickly blue white of my 2 MTB lights.

This cutoff beam mounted at bar-height gives a broad verge to verge sweep of very even light that projects well ahead. Mounted at fork-crown it casts shadows on the smallest imperfections/obstacles in the road showing them in stark relief. Activated the second beam adds a neutral white flood/spot to the show, projecting far ahead and is excellent for rough stuff/trails or ‘flashing’ other road users.

The modes are sensible and I find that medium is good enough for unlit lanes at 20mph. 7.5 hrs. There is a memory for last mode used. Superhandy. There is a smart ‘pulse’ mode rather than flash and I really like this option for urban/city use.

It’s not blinding at all and feels so much more natural and non-glarey that I seem to see much more than I could with much higher lumen lights that tend to somehow just throw some light everywhere and yet also give a headache inducing tunnel-vision/high spot centre.

If I could have afforded the PR1600 I’d maybe have gone for that to cover more bases offroad at higher speeds, but as it is I’m well chuffed with the 900 for road commuting, touring and more leisurely pitch black offroad jaunts.

Runtime remaining (in each mode) is shown in hrs on an easy to read top display.

Have had many lights over the years and this is hands-down the most useful and impressively-designed I’ve yet used. The cutoff beam is a revelation. No more constantly rotating the light on the bars to point uselessly at the floor in front of the wheels. It dazzle. It just lights the road ahead. Exactly what I wanted. Also works as a powerbank, which is a nice bonus.

Highly recommended.

Here’s a good forum thread I think they compare beams of Moon Meteor to cutoff beams like Ravemen IIRC
https://forums.mtbr.com/lights-night-riding/self-contained-z-1105995.html

Here’s a few pics I took tonight. The unit with readout. The cutoff beam (High), both emitters (high – 900lm max) and cutoff beam (lowest setting)

*Erratum

It doesn’t dazzle. It just lights the road ahead.

And the pics are not in order! You can work it out 😎

OP If you want a cutoff beam for road use I’d return the Meteor if poss and get a Ravemen or Fenix or something?

Must admit it chisels me off that mfrs tend to market lights to commuters/roadies etc yet the beams are just woeful/dangerous for purpose

+1 on the Ravemen lights….I got the PR1600 a while back. It’s a great light.

Not sure you could suitably replicate a ‘dipped’ beam with electrical tape. All you will end up doing is losing more of your available light, I think.

I’ve different lights to you but I use sugru rather than electrical tape to direct the beam. Mainly to stop it blinding me. It must be better than electrical tape.

I bet you could achieve something akin to a dip if you used a cowl but I bet it’d have to be pretty long to be effective. Tape? – nah (IMO)

I’ve taped off the top half of an ebay special light, using masking tape, it did sort of work, but really nothing is a match for the real thing.
‘Something akin to a dip’ is actually a reasonable description of how it worked.

Here’s some more pics of the Ravemen – the PR1600.

Ravemen PR1600 bike light – Mini Review

I bet you could achieve something akin to a dip if you used a cowl but I bet it’d have to be pretty long to be effective. Tape? – nah (IMO)

I tried this ages ago with a home-brew, triple LED with quite a spotty beam. Cut an extended cowl from a piece of redundant flexible mudguard and attached to the top of the light with a zip-tie round the light. It sort of worked, but the cowl had to be both very long and quite extensive to make any significant difference. I extended it a few times, but it never really worked as planned.

I think I concluded that it was a dead-end tbh

You could probably do it with lenses. My german light uses a combination of reflectors and lenses to achieve good beam patterns

I tried this ages ago with a home-brew, triple LED with quite a spotty beam. Cut an extended cowl from a piece of redundant flexible mudguard and attached to the top of the light with a zip-tie round the light. It sort of worked, but the cowl had to be both very long and quite extensive to make any significant difference. I extended it a few times, but it never really worked as planned.

I think I concluded that it was a dead-end tbh

Same. much more effective to just angle the main area of the beam so the top cuts off at/below registration plates

The Ravemen and the Fenix look good, but neither of them can be run inverted under an out-front mount.

^ (wants better than moon, inverted, on a stick) 😉

The Ravemen and the Fenix look good, but neither of them can be run inverted under an out-front mount.

That describes the one you bought. Why did you buy a light with a specific way up, if you were intended to run it upside down? Not being funny, it’s just I research the arse off every little purchase I make, so it’s an odd thing to do!

DezB, not sure how the Moon Meteor Vortex cannot also be mounted upside-down?

Beam shape:

https://road.cc/content/review/270067-moon-meteor-vortex-pro-front-light

Same. much more effective to just angle the main area of the beam so the top cuts off at/below registration plates

Problem is, even a relatively narrow ~90deg beam that means pointing the brightest part of the beam at your front tyre. Which is completely useless. A proper beam pattern projects most of the light right under the cut off, because that’s the bit that hits the road at the most acute angle, which gives the same level of illumination as comparatively little light projected straight down infront of you. The STVZO standard is 10lux on the road surface at 10m, which with a good beam pattern is about 30 lumens at the LED. Even the best ~100lux lamps are only emitting about 300-500 lumens, but the road is lit up like a 2000 lumen off road light.

The benefit to the rider is the beam pattern.

The benefit to everyone else is the cut-off. And remember it’s a cut off, just anglign a cone of light down so the drivers eyes only get the outer bit is still really bright compared what’s above the cut-off on a car’s dipped beams.

The Ravemen and the Fenix look good, but neither of them can be run inverted under an out-front mount.

If you can’t run a dynamo for some reason, have a look at the e-bike versions of the dynamo lights that mount to the fork crown. A lot will run at 6-12V, i.e. they’ll run fine off a standard offroad light battery (7.2-8.4V) if you can solder on a plug. And being ~500 lumens, the runtimes are massive.

B+M and most manufacturers etc also do mounts that attach the lamp in front of the stem.

Lower (fork crown) is much nicer though as it casts shadows into potholes.

https://www.wiggle.co.uk/lezyne-lite-drive-stvzo-pro-115l-front-light/

Don’t know if this is so new it isn’t in the shops yet, or if it’s so old it’s been and gone.

You can also buy a universal fork-crown adapter/mount that accepts regular bar-mounts. Rixen Kaul do one, so do B+M iirc. Could be a fairly simple DIY even.

There’s also the Minoura CS500 mount, which puts a light below the stem

Problem is, even a relatively narrow ~90deg beam that means pointing the brightest part of the beam at your front tyre. Which is completely useless. A proper beam pattern projects most of the light right under the cut off,

Completely agree. I was just saying that you’re on a hiding to nothing trying to fashion a decent road beam pattern from an off road light and a DIY cowl – it’s no more effective or satisfactory than just pointing the beam at the road. And with the beam pointing at the road, you get a great view of the pothole you’re about to ride into.

And I don’t completely agree. I use an older diablo and joystick (not at the same time) and I can angle the brightest patch of light of light from 3-4 feet from the front wheel to about 15 feet away.

and a 90degree beam would be massively wide, surely? Your main beam spread 15 feet wide at 9 feet from your bars?

As an aside – isn’t it daft we are having to have this discussion in 2020? LED and battery technology is long-proven, but it’s just taking ages for battery-powered bicycle (road) lights to get up to motorbike/scooter standards in the beam/reflector dept? I spent hours and hours researching and scouring forums, reviews etc to find something affordable and powerful. Yet for circular-beamed mega-lumen glarey-dazzlers we are spoiled for choice!

and a 90degree beam would be massively wide, surely? Your main beam spread 15 feet wide at 9 feet from your bars?

Depends on the light, but most seem to peter out rather than having a cut off which makes them impossible to ever really avoid oncoming traffic.

My bar light claims 120deg with the wide lens fitted. Haven’t ever measured what that corresponds to.

And if you did, it’s a cone of light, so you only get a point up the road that’s lit up, and it slopes off either side, rather than a nice flat cut off showing the hedges etc.

As an aside – isn’t it daft we are having to have this discussion in 2020? LED and battery technology is long-proven, but it’s just taking ages for battery-powered bicycle (road) lights to get up to motorbike/scooter standards in the beam/reflector dept? I spent hours and hours researching and scouring forums, reviews etc to find something affordable and powerful. Yet for circular-beamed mega-lumen glarey-dazzlers we are spoiled for choice!

I suspect because most “manufacturers” aren’t interested in designing anything. It would cost them money to design a reflector from scratch, get it tested, and market it. Rather than just make a 3000 lumen light for £20.

I just used a bit of plastic drain pipe to solve a similar problem when riding on the road. Ugly but simple clip on clip off solution to blinding oncoming traffic.

For dynamo lights, the Busch & Muller IQ-X can be rotated in the mount. So it could hang down from your bars, bit still have the beam the right way up.
Not sure if there is anything similar for battery lights? There is an ebike version of the IQ-X, so could connect that to a battery pack.

DezB, not sure how the Moon Meteor Vortex cannot also be mounted upside-down?

Er, cos .. The lens has a cowl over the top and a cut away at the bottom ?

∆ Yes but I think it’s broadly agreed on the thread so far that the cowl and the cut-out don’t really do anything (hence no point trying to modify them) as the beam characteristics are all determined the internal reflectors.

So what’s your question then? 😉

Er, cos .. The lens has a cowl over the top and a cut away at the bottom ?

Looking at the beam and having seen the unit I think the tiny lip at the top is simply to reduce distracting glare for the user, a little blackout paint or insulation tape should see to that. The circular beam will stay circular, probably. Don’t quote me 😎

OP do you mount the Vortex upside down?

Wait this is getting complicated…

Yes I mount the Vortex upside down.

The Moon Combo Mount product pic actually shows it with a Garmin on top and an upside down Vortex below.

I bought the Vortex because a) it got good reviews as a road light, b) it was cheap, and c) the only one product which is exactly what I wanted (the inverted STVZO Lezyne I linked to) is out of stock and anyway thrice the price.