I’m considering buying a bike mount from fasttech, however i’ve noticed that unlike a car headlight, a flashlight beam will blind oncomers, so i would like to use a mirror surface to reflect the top half of the beam back into the light so it will come out the bottom half which would be aimed far enough ahead to illuminate what i need.
Any suggestions what to use to accomplish this, how much light i will lose, or better solutions?
how about getting another lense, I have some sticky back alu foil, cut a semi circle of appropriate dimensions and stick to the inside of the lense to give a flat top to the beam, might not work but might be worth a try.
So you need a hood like this one, but with a mirror finish on the underside of it:
-Garry
-Garry
I’d just aim it down a bit so that the spot is some 30m in front of you. That’s far enough that you shouldn’t outrun it (unless you’re doing 30mph+ descents) and the spill is still useful for being seen at a distance as well as reflecting off signs and such like. It’s how I run my commuting light (500lm or so) and I haven’t had any complaints or flashes. As long as you’re not aiming it straight at oncoming drivers, any light you put down the road will be marginal compared to a set of car headlights.
Any type of mask will cut off a lot of useful light and a hood would need to be at least as long as the diameter of the lens to be of any use. If you do end up using a hood, experiment with some shiny foil on the underside before you polish it as I’ve read a few examples where a polished hood throws a lot of light at the front wheel which messes with your eyes and stops you seeing decent distances at night.
An eliptical TIR works perfectly if you can find one the right size. I have one in an L2 that I use on my bike.
you can also get elliptical lenses for Magicshine style lights which do a similar job. You do lose a fair bit of through though.
Personally, I’d advise anyone with only one light for commuting to put it on their helmet. Being able to light up a car at a junction has saved my bacon multiple times. Off-road it’s less clear as it depends on the type of trails you ride.
interesting ideas everyone, though the just aiming it down doesn’t work well for me, i want more distance for going faster but without causing a danger to others
@gords, i like your idea, an improvement on mine
@garry, good idea also, it can be customized to a better beam profile which opens up new possibilities
@Itinifni i’ll have to look into those lenses
I don’t have any beamshots but it’s the same beam profile as an automotive fog light.
Hi Itinifni, any chance you can send us a link of where you got that optic? Is that the solarforce L2 in your pic? Did the optic slot straight in like a P60 reflector or did it require some modification? I too have purchased some similar optics but they don’t fit any of my lights, would love an optic that slots straight into a P60 host.
The optic is available here. I also used the lens holder shown on the same page to properly position the TIR above the LED.
Yes, that’s a S/F L2m in the picture. There was some modification to get everything to work properly.
The LED mounted on a stock P60 pill will sit too low in the head for the TIR. I removed the LED and star from the pill and mounted a copper shim on the pill (I used 3/4” copper rod, I think around 6mm in height). The star was then attached to the copper with thermal epoxy.
The diameter of the optic is fine but the optic holder is to large so I had to trim the top down to fit in the head. It still positions the optic properly above the LED.
I bought 4 of the optics on the page, switching them is as easy as unscrewing the head.
You can see how I made the pill here.
if you want distance then an elliptical isn’t going to do any better than if you aim the light down - for that oval beam you trade off throw, for all the ones I’ve tried anyway. Sounds like a slightly defocused aspheric might work better.
or a light on the bars and one on the helmet, then you can have the best of both worlds, near in flood that doesn’t annoy drivers and a throwy helmet light for distance work.
You’re spot on as far as trading throw for a wide beam. I like the way it lights the sides of the road though, and at the speed I ride, let’s just say I’m not out driving my headlights.
At any rate, I always have a second light on the handlebar for distance. I haven’t tried it but your probably right that adding a helmet light would be best.
Automotive headlights shroud the bulb or filament. Doing the same with an LED flashlight should go a long way towards reducing how badly it blinds others.