Using a phone as a front light

General cycling advice ( NOT technical ! )
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Re: Using a phone as a front light

Postby Jdsk » 12 Dec 2020, 11:17am

thirdcrank wrote:Trivia: I see that tomorrow is the anniversary of the death of Dr J

Tomorrow's editorials?


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Re: Using a phone as a front light

Postby Mr Tom » 12 Dec 2020, 11:18am

I think I just need to sort out a new battery for my back-up light as you say! I've got dynamos on the two bikes I normally use. This was just getting caught using my folding bike which had been in the garage for ages and not expecting to be out so late

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Re: Using a phone as a front light

Postby thirdcrank » 12 Dec 2020, 11:25am

Mr Tom wrote:I... not expecting to be out so late

For me, that's the nearest thing to a cast-iron good reason that I can think of, and most of us have been there. I would say, though, that there are now enough cheap, reliable, bright, compact bike lamps available to make the situation easier to avoid.

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Re: Using a phone as a front light

Postby simonhill » 12 Dec 2020, 3:54pm

Thanks for the tip. All knowledge is useful, to me anyway. Maybe not for the smug ones who carry half a dozen spares and would never be caught out.

I've cycled with a penlight (mini mini maglite) as a front light/torch. Piece of string through keyring hole and round my wrist so I could drop it if I needed to suddenly grab the bars, brakes, etc. ......if needs must.

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Re: Using a phone as a front light

Postby simonineaston » 12 Dec 2020, 4:47pm

Fits neatly into that box marked, "not great but better than nothing", which is sub-titled in faint pencil - I used an H, I think - "emergencies only".

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Re: Using a phone as a front light

Postby mattsccm » 12 Dec 2020, 4:49pm

Why knock it? Not much good to me as I haven't a clue where my mobile is most of the time and care less. If it was a choice between riding with no light or that then surely its better than nowt. Can't see why it should be laughed at.

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Re: Using a phone as a front light

Postby Bmblbzzz » 12 Dec 2020, 5:49pm

Good emergency dodge.

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Re: Using a phone as a front light

Postby AndyK » 12 Dec 2020, 5:56pm

Jdsk wrote:
Sweep wrote:Folks' desire to/think it clever to use their phone for everything puts me in mind of crappy gadgets from the 50s (before my time but have seen the ads) which proclaim, "it's a ****, it's a ****, it's a ****** but do none of the things very well.

I won't comment on what other people think about other people or their devices.

But my iPhone carries out a vast number of functions very well. And is smaller, lighter and cheaper than the range of devices that I'd otherwise use. Just brilliant... and unpredicted!


My Android phone likewise carries out a vast number of functions very well, and is even cheaper than your iPhone. :-)

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Re: Using a phone as a front light

Postby mjr » 13 Dec 2020, 12:46am

thirdcrank wrote:There was a time when bike lights were completely and utterly unreliable and usually not very bright.

Last Tuesday. First time in ages I rode a bike needing battery lights after dark. Chuffing back light batteries apparently came loose, so hit a bump too hard and out it goes!

Backup light used but most battery lights are still rubbish.
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All the above is CC-By-SA and no other implied copyright license to Cycle magazine.

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Re: Using a phone as a front light

Postby thirdcrank » 13 Dec 2020, 8:30am

So much of this is comparative.

Never Ready and similar front lamps used a specific (4.5V ?) battery with two brass-coloured contacts, one on top intended to contact the switch and another on the front intended to contact the bulb. The only batteries on retail sale in those days were the zinc carbon type and for long enough, not "leakproof." They had no date-marking so may have been in the back of a bike shop for a while.

Rear lamps were marginally better in that they used to use what were then known as U2 cells - more recently size D. For long enough they used a single cell and were switched on by screwing in the tail cap. A later, more aerodynamic LOL style had a switch and eventually a new BS (BS 2158?) required two U2 cells.

Filament bulbs were unreliable and even a set of lamps in working order produced a poor light, especially at the front.

The Night Rider type of lamps, which clicked into a new type of bracket F & R were IMO the apogee of filament-bulb bike lamps. Bulbs and cells had improved quite a lot, the contacts were improved but still unreliable but they were still quite heavy, and easily nicked if left on the bike. ie Plenty of reason not to ride around with them on unless you needed them, but too bulky to slip off and carry round if the bike was unattended.

NiCad batteries were a great innovation - compared with dry cells - but when discharged, the power dropped off a cliff edge. The "memory effect" advice was to discharge them fully so spares were imperative. I got into the habit of carrying a spare of each F & R in the side pockets of the Camper Longflap. The charging régime had to be strictly followed. My personal experience includes year-round commuting on rotating shifts.

Gell cells were a great improvement, but even heavier. Totally reliable with care, and obviously needing a charging régime.

Then, along came LEDS. A bit pale in their early days but now bright, lightweight, compact and in an emergency, standard batteries widely available in filling stations offies, etc., and cheapo lights in supermarkets.

At the same time dynamos have improved beyond measure; in particular, nice hub dynamos are available for lightweight bikes.

We're in Supermac territory with bike lamps. ("You've never had it so good.")

That's why I think it's best to save the phone battery so you can ring home if you get a puncture.

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Re: Using a phone as a front light

Postby Brucey » 13 Dec 2020, 9:54am

phone as a front light..?

Reminds me of the expression

..when all you have is a hammer, everything starts to look like a nail....


BITD battery lights were so dire (and tyre driven dynamos such a can of worms) that I fitted a SA dynohub to my training bike. It added about 700g to the bike, which seemed to me to be about the same weight as the many sets of batteries and spare lights which I'd otherwise be forced to carry. I guess I did about 60K miles on that setup, about half them in the dark. One I'd learned not to ride at 40mph downhill with the lights on, and got into the habit of changing the bulbs once a year anyway, I had no bulb failures on the road. I kept a spare pair of bulbs wrapped up and stashed inside the headlamp shell anyway, just in case. By modern standards the light output was feeble, but at the time it was still more than a standard battery light would manage. I genuinely couldn't (and still can't) understand why more people didn't do likewise.


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Re: Using a phone as a front light

Postby rmurphy195 » 13 Dec 2020, 10:11am

Better than nowt in an emergency, but given the battry life of modern phones I sgouldn't think it would stay alight very long. Additionally, I'd be concered about what such use would be doing to the screen! Assuming you are talking about illuminating the screen of course, rather than using the built-in flash unit whcih I suspect wouldn't be a very good option.
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Re: Using a phone as a front light

Postby markjohnobrien » 13 Dec 2020, 12:08pm

Jdsk wrote:Everyday I have the dynamo lights, the back-up battery lights, the helmet position lights and wrist indicators.

Touring I have those (except for the wrist indicators) plus a head torch... and a companion with all of the the same.

But I felt for that comment about run-down back-ups in the bag!


Same for me: on my dynamo light bikes, I always have back up battery lights to ensure resilience in the very unlikely event that there’s a problem. It’s always a good idea to have a steady rear light and additional flashing rear.

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Re: Using a phone as a front light

Postby Megalodon 5 » 13 Dec 2020, 2:13pm

If you crash, you do not want to destroy your phone. i.e. don't

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Re: Using a phone as a front light

Postby DevonDamo » 13 Dec 2020, 2:34pm

Informative thread.

What I've learned is that if ever I escape a burning plane by fabricating a make-shift parachute from my picnic blanket, as I touch-down, I'll be met by a CTC welcoming committee tutting and pointing at much better-performing models in their Parachute catalogues.