Rear lights: which is best, continuous or flashing?

guerney

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being visible is not the problem at speed i need to throw the light so can see what is coming id not go much faster than 25mph in pitch black with what i have atm.


if you cant cool the led at max power it will blow up in seconds like a old cpu with no heat sink.

you can use a buck converter to power the leds so limit voltage and current but dont try that with the bikes batt as a power supply.
How about filling empty space within, with non-electrically conductive ferrofluid to conduct heat to the torch shell casing, after adding heat vanes to increase it's surface area? Then air passing by at your usual 25mph night time speed would do the rest.
 

soundwave

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i basically did that just with baby oils as non conductive and also had a heatsink behind the led

you can get a power driver with this one.

 

guerney

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i basically did that just with baby oils as non conductive and also had a heatsink behind the led

you can get a power driver with this one.

Very bright for one LED!

>>Light output :Up to 4022 lm @ 32 W

I think oil becomes more viscous, or some do, as they heat up, but ferrofluid would continue to move as the LED rapidly flashes, resulting magnetic fields would keep it moving - still, you'd need enough rapid transfer of heat away from the casing - cover it with a bunch of heatpipes, or pipes containing freon circulated by a small motor through a large enough radiator, like at the back of your fridge?
 

soundwave

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yep you would need ln2 pumped over the heat sink if it was that small @32w for a single bike light
 

guerney

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I've just taken a look at mine, from the front in a darkened room, and crikey, yes, they are definitely an extremely bright, dazzling white, and yes possibly blinding. I was quite surprised as it's the first time I've ever taken an actual look at the light from a forward perspective. I just switch it on and go. Never have need to check as it's powered direct from the battery.

Nothing like those old large metal ones, powered by their own batteries, which you'd slot onto the front of the bike. They were very mild by comparison.

With that said, I certainly wouldn't be up for taking lectures from motorists who come at you full beam on an unlit road. I challenge any cyclist to stay fully orientated in direction before such a car passes.
Even my weak little 1.5 watt Junstar Bafang headlight looks dazzling when viewed in isolation in the dark, but they can't hold a candle to car headlights, even when they're not on full beam. Honestly, whingeing drivers complaining about cyclist lights being too bright for their precious little eyes, which don't see cyclists when they don't sport bright lights, need to gain a sense of perspective, wrapped up safe barging about in their cyclist mincing steel cocoons on wheels:

 
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soundwave

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ill have one buy next week
 
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soundwave

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AndyBike

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This may be of interest to you:
OOOO kerb appeal
when carrots don't work.


even with my 8000lm light i cant go flat out as just cant see far enough., the light in the vid was this one and absolute crap but my wheel was not bent in half so better than nothing ;)

Sure thats 8000lm ?. mine is an exposure at 2000lm(3200lm on reflex mode) and im sure mine projects more than yours.
Yes I know its advertised as that, and above these later models, but it just doesnt look like its 4 times brighter than my lamp.
Also - is your mates rear wheel in true ? looked to be wobbling about a bit.
 

soundwave

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each of the leds is rated for 1000lm but doubt they are running at full power so more like 6000lm real world but they all over rate the light out put
 

AndyBike

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each of the leds is rated for 1000lm but doubt they are running at full power so more like 6000lm real world but they all over rate the light out put
Sorry, thought the lamp in your ebay link was the 8000lm one you were referring to, not the magicshine one you have in the you tube link.

Those cheap ones coming out of China may claim 8 or 10 thousand lumen, but clearly they are well off that.
Keep in mind a car headlight is between 2000-4000 lumen. So a wee Chinese bike light is claiming to have the power of a pair of the top end car headlights on full beam.
 

jimriley

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I prefer cycling at night - when else do cars reduce in number enough, for one to enjoy the road? Mind you, drivers are much worse during pub hours, and after they close... even blinder than usual - half awake and slow to react. This helps:


It's prevented many a collision with people and vehicles, also works on other animals. Gives you a loud retort to rude beeping *sshole drivers.
Just bought a Hornit - it's loud!
 
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guerney

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Just bought a Hornit - it's loud!
Yes it is! It projects really well too - I don't like the weird shrieking setting, the beep works much better IHMO because it sounds like a noise that a vehicle would make. But the beep is only 120db... still, it gets through car body shells and into driver ears. The little switch to horn jack plug does fall out occasionally, so best test before you ride out. I might ziptie that on or something. I beep everyone and everything pre-emptively, useful for alerting drunks wandering all over the road at night, but especially useful for drivers. Those two AAA batteries last ages. It really annoys drivers, which makes a nice change. A driver cut in front of me with millimetres to spare the other day and beeped, so I beeped back - I heard him shouting "What's he beeping about?"... and because traffic slowed and I had an ebike, I caught him up and shouted through his window that he should allow bicycles as much room on the road as a small car.
 
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Oct 20, 2021
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Just bought a Hornit - it's loud!
This drunk wandering fool didn't know I was approaching until I beeped my Honitt 140db. If he hadn't changed direction and if I had swerved, the passing car might have caused me bodily problems. It's well worth 20 pounds IMHO.


 
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guerney

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sjpt

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They look good, better than the lollipop flag we had when we had children (35 years ago) on the back of the tandem. Do they flip back if you go through narrow gaps? They look maybe a bit too rigid?

We also had a high flag on the trailer with a light at the bottom that lit the entire shaft and (slightly) the flag itself.
 

guerney

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They look good, better than the lollipop flag we had when we had children (35 years ago) on the back of the tandem. Do they flip back if you go through narrow gaps? They look maybe a bit too rigid?

We also had a high flag on the trailer with a light at the bottom that lit the entire shaft and (slightly) the flag itself.
The reflectors wobble and bob about a bit on springs, and flex when the bike is propped up against a wall. I haven't been able to go out for a ride yet, hope they don't make any loud noises. If they only make springy noises when going over potholes, I'd find that acceptable. Let's see how long it lasts! The plastic clasp holding it to the rack looks a bit flimsy, I might try to reinforce that with two metal strips.
 
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