Bikelighting

The purpose of this evolving webpage / semi-blog which I started in late 2009, is to share what I have learned in my long quest for an "optimum" bicycle lighting system, so that others can make their own, and / or offer their suggestions for improving both my designs, and my crude attempt to communicate them. It's about time this became a team effort.

My BLOG :-

http://suburbanbristolcyclist.blogspot.co.uk/

My YouTube videos (WARNING SOME CONTAIN SWEARING ) :-

http://www.youtube.com/user/yangtse55?feature=mhee

My motorcycle broke in 1987 and I had no money to fix it - being only three years into the joys of home "ownership" with a borderline salary and interest rates in the -teens. Luckily I vaguely remembered that I'd occasionally seen perfectly ordinary-looking people actually riding 2-wheeled vehicles several miles without the aid of engines.

So I borrowed my brother's ten-speed.

Ten years of motorcycling had come to an end ... though my mum was convinced a 27 year old vegan was never going to manage - due to my "not getting enough protein" - but she was wrong, and 23 years and 40-odd thousand miles later, the only place I want to be on a Sunday is on a 50 mile group ride in the country.

"A pair of 1900 oak Ever Ready Bicycle Lamps".

Photo "borrowed" from "The Flashlight Museum"

For the first 7 years of cycling the 4 miles to work and back, I was fully legal, lighting-wise, in that I had the standard "Eveready" 2 cell lamp front and back - hardly changed from my childhood - each complete with its fully law-complying pathetic 1 watt glowing filament "now with added krypton" - though I invested in U2 Nickel Cadmium rechargeables and fitted "Bulgin" power sockets for easy charging with my highly dodgy DIY charger. In those days I was extremely short of funds, but also sceptical that proper lights were even feasible on a bicycle, and I relied on my wits and my reflective Sam Brown belt. But this was before the "school run" era, so the (suburban) roads were emptier, and tempers less frayed. I was yet to even notice that cycling was getting me fit - having always had a distaste of anything remotely resembling "sport".

Winter 1994 (??)

In the early 90s, I discovered the early form of the Internet - USENET, and one of the first newsgroups I plundered for information was "rec.bicycles.tech", and very soon had a 12 volt, 7AH Sealed Lead Acid battery I found for approx £10, and a couple of cheap, after-market car lamps which were under £5 each. The charger was initially more or less the same dodgy DIY thing I'd always used, but, fearing for my house I bought a proper one from Maplin.

I experimented with 5 watt and 10 watt lamps, but inevitably ended up with the full 21 watts front and back. (The same as brake and reversing lights on a car.) The usual choice for DIY enthusiasts was the 20 watt MR16 spotlight, but it didn't seem to do what I wanted.

So by 1995, I had better lights than any other cyclist I encountered (although in those days, cyclists, per se, were even more of a curiosity in the very hilly city where I live.) The music on my Walkman was becoming more up-tempo (I had just discovered the tail end of the rave scene and was out pounding the boards every weekend). I started consciously cycling for fitness, and I got a bit more "assertive" in the way I interacted with the "caged" community - perhaps buoyed a little by having more confidence in being seen.

The only photo I have that shows anything like that early incarnation. It's two bikes on, and with a later front light.

The Italian car horn was always good for a laugh.

Until recently, I was never very interested in shining a beam ahead of me, as my cycling was always almost exclusively on fairly well-lit urban and suburban roads without too many potholes. My priority has always been to be seen obliquely at junctions and when overtaking long queues of static cars on the offside, or in the "advisory" cycle lanes motorists are sadly wont to drift into or turn across - to which end I used to occasionally deploy a couple of these I found on special offer - angled outwards - though I find detachable, battery-operated lights almost as annoying as flashing ones.

I was content with my lights for about 10 years - until the point where it dawned on me that I was having to buy a new (heavy) Sealed lead-acid battery every couple of winters (they aren't ideal for that kind of use).. but the alternatives (Nickel Cadmium and Nickel Metal Hydride) were a lot more expensive - 4 times the price for a given capacity - and only available up to approximately half of the capacity I needed to reliably power 42 watts / 3.5 amps of lamps for up to an hour on an overnight charge.

My previous investment in a charger led me to strongly consider rather exotic and expensive "Cyclon" lead acid batteries - having had problems in the past with Nicads not standing up to my careless treatment, but all my reading told me I really ought to embrace the apparently more user-friendly NiMH. One annoying issue is self-discharging which means that you need to charge them at least once a month even when you only need to use them occasionally.

So I needed to drastically reduce my power consumption, without sacrificing light output.

Publicity photo of Nikola Tesla sitting in his laboratory in Colorado Springs circa 1900. (From Wikipedia)

Winter 2005 "A fluorescent lamp will never work on a bicycle !"

For maybe as long as ten years I'd had a project on the back burner to use a fluorescent lamp on my bike, (one of the flat "2D" type) - so I brought this forward .. and realised that if I carefully removed the business end of a 9 watt "mini-spiral" compact fluorescent of the type I had been using so successfully at home for some time, I could actually fit it, and the existing car lamp diffuser and reflector, into a convenient size of storage container I found at Asda.

The electronics was from a Maplin caravan lamp which I had to tweak a little to suit the new tube. I'm fairly certain this £20, 10-ish watt lamp was about as effective as the 21 watt one that preceded it, and I was sorry to replace it after 3 years - contrary to reputation it stood up to being bounced around, and freezing weather didn't seem to delay its starting or to dim it in use.

Thence to the rear lamp...

I had a half-hearted stab at putting a red filter (Christmas pudding wrapper !) in front of the afore-mentioned10 watt 2D fluorescent, but it was always a non-starter as fluorescent lamps are hopeless as a source of red light. There are 15 watt red CFLs available - though I don't know if they actually have red phosphor or are just painted.

So I settled on 25 red, ultra-bright ("5 candela") LEDs I bought from my battery supplier, fitted in an unusually thin storage container I had spotted at Ikea. (Designed to store herrings ?), and backed-up with my emergency Cateye LD600 lamp - though I doubt I used it in the flashing mode very often as I hate flashing bike lights - there's really no need for it if you use enough power.

With the power requirements now down to about 12 watts, I was able to ditch the lead-acid battery and replace it with a much smaller and lighter NiMH one.

It was a bit on the large size, but I couldn't resist the over-the-top IP65 waterproof housing from B&Q, combined with salvaged PC hard drive power cables for added comedy effect.

I have just "retired" that first battery after 4 winters .. it suddenly seems incapable of powering all of my recently upgraded set of lights (20 watts / 1.5 amps) for more than half an hour, whereas I would have hoped for much closer to the planned 2 hours - perhaps something to do with some very careless charging over the years - but at £25.25 inc postage it's still a bargain. All similar batteries I have found, have been at least twice the price - with no certainty that they would last any longer. Maybe one day soon I will look at Lithium ion.

http://www.component-shop.co.uk

Winter 2006 / 2007 "More of the same."

The next winter, I upgraded the rear light to 49 LEDs, plus 10 at the sides, and half-heartedly threw together a couple of experimental one watt, twelve-LED front lights (I had originally planned to modify my Cateye lamps) I thought of them partly as "emergency" lights, and incorporated specific provision to run these, and the 2 watt rear lamp from AA alkalines.

They ultimately turned out to function well beyond expectation and even threw enough light forwards to be useful on rare rides on unlit paths..... over the next year or two, it was to dawn on me that lamps made with steadily improving super-bright LEDs, would soon end up being sufficient most of the time,

I decided against fitting the un-focussed 1 watt LED in the middle !

This configuration contented me for two winters. It was useful to have all three technologies available to compare and think about over the next few thousand miles.

https://sites.google.com/site/gentlegreen/bikelighting

I never found the 20 watt QH MR16 spot lamp (bottom left) very effective -

in spite of its having been the mainstay of the DIY

bike light scene for a long time.

Winter 2008 - All Change !

Earlier in the year, while buying camping equipment, I had discovered the "UFO light". An impressively bright, but bonkers thing (£3.99 at Wilkinson Hardware) with 48 x 5mm LEDs in parallel, inadequately powered by three AA alkaline cells which could only supply the nearly one amp required for about an hour, before running low and causing the LEDs to get more and more dim - though they give useable light for quite a long time. It relies on the sheer number of LEDs and the relatively high internal resistance of the battery itself to prevent the LEDs melting - probably contributing to its efficiency.

The elegant housing would have taken me an age to emulate, and it was simply demanding to be adapted for 12 volts and made a bit more robust electrically.

I made two cuts and soldered in a few wires and a resistor :-

(Typically, in practice the correct resistor turned out to be almost twice the value I had calculated .)

http://www.trainweb.org/girr/tips/tips7/led_vf.gif

For optimum efficiency and to prevent damage, 5mm LEDs are best operated at between 20 and 30 mA - at which point they have a certain "forward voltage" - from which you can calculate the correct value of resistor to limit the current to that range. The smaller the voltage across the resistor, the less power is wasted. Using a 12 volt supply, red LEDs (Vf 2.1) work best in series strings of 5, and white LEDs (Vf 3.3), in strings of 3. The trade-off with the series / resistor arrangement is that if the battery voltage drops by more than a volt or two, the LEDs suddenly go out .. so I may one day consider shorter strings and electronic regulation, but in practice, with a good battery, it has yet to be a problem.

I had to enlarge the hole in the middle with a fretsaw to take the 40mm plumbing coupler for the spotlight.

The jubilee clips are actually an improvement over previous lamps that were simply hanging off the handlebar on cable ties. I have steadied the bottom of the assembly by taking galvanised wires down to the fork crown - hopefully I will eventually come up with a more elegant solution.

I won't say it's "perfect", but this 3.5 watt lamp is much more effective than the 10 watt fluorescent lamp it replaces - and the 20 watt incandescent before that - a nice combination of a large area, good visibility from the side, and multiple sharp points of light that punch through the murk and say "bike".

A particularly useful function of its broad, but somewhat polarised "beam", is in picking out otherwise un-lit cyclists and pedestrians at quite some distance who are wearing reflective material. After some thinking, I trimmed the "reflector" down to almost just the top part - which serves to keep the light out of my eyes and hopefully this maximises visibility from the side.

It's difficult to take photographs of this sort of thing, but hopefully this shows how well the lamp performs in a real situation.

(This is the upgraded version of the lamp - rebuilt with better LEDs.)

The front lamp was so successful, I simply had to get shot of the "tupperware effort" on the back, but of course these lamps don't actually come in red, so I ordered up 50 of the brightest 5mm red LEDs "Light Of Victory" of Hong Kong had to offer. These give a claimed 33 candelas - in theory 6 times as bright as the ones I had been using thus far, and cost me about £15.

To make things easier, the first thing I did was mark the "positive" lead of each LED with a red pen and bent the leads horizontally - approx 5mm from the bodies using pliers.

I then used the front of the lamp as a jig to space the LEDs correctly, picked them up a pair at a time between thumb and forefinger, twisted the leads together (wrapped each around the other in turn), and trimmed any excess. I made up sub-assemblies increasing in size - testing them at each stage with a battery and resistor.

Rule 1 of good soldering is to make the connections work (mechanically stable) even before they are soldered.

This is actually the current front lamp- made brighter by rebuilding with 55 candela LEDs

(perhaps not quite enough of an improvement to fully justify the effort, plus the increase in price from £3.99 to £18 for parts).

Finally, resistors were fitted to the positive ends of the strings, the junctions were soldered, then all the positives and negatives were soldered together.The LEDs were supplied with the correct resistor to power each single LED from 12 volts, so I simply paralleled those in 3s or 5s - no point in wasting them for the sake of neatness.

Some rubber sleeving and a few blobs of hot-melt glue and the job was done...

(Of necessity, in the case of the rear lamp, two of the strings contained only 4 LEDs.)

The rear lamp has ended up being the great success of the project.

A key advantage is that its beam pattern is hemispherical so it throws light upwards and sideways which may help if I'm riding near to large vehicles with blind-spots - though of course I try to avoid that.

As can be seen in this photo, it competes favourably with the other red lights found in traffic

(That car has its brake lights lit !)

Winter 2009 - and the need to actually see where I'm going.

Having spent 22 years riding on reasonably quiet, well-lit suburban and urban roads and optimising my lighting to suit, I made my homeward route longer and more scenic, and added several new challenges. :-

I was already prepared for the unlit and fairly rough, but quiet country road with the large lights, plus some MR16, 4 or 5 watt, Cree XRE-based spotlights. These are also satisfactory when riding through unlit wooded parkland.

The biggest challenge became evident the first Monday after the clocks had gone forward when I rode home on a poorly to completely unlit mixed use path with wet fallen leaves and branches.

I noticed several things. :-

1. Due to now travelling in the opposite direction and on the Bristol to Bath railway path (i.e towards the city centre) I was directly encountering a lot more cyclists than I had in the 22 previous winters.

2. Perhaps 1 in 10 of them were somehow finding their way home in the dark with no lights at all - not even reflective clothing - there were even invisible people pushing prams. I can only suppose my night vision is much worse than others'.

3. Many riders had fiercely bright, point source LED lights aimed uselessly high - so as to dazzle oncoming cyclists.

4. Even more insane were the strobing ones - some of which must have been impairing the vision of those cyclists themselves - let alone those approaching them. I hope none of them (or anyone else subjected to them) is prone to epilepsy.

I immediately realised I could not use my large front light in this situation - even the rear one is much too bright ...so I only use my dipped beam and fitted an alternative, muted rear light.

In fact I now only use my big front light on the flash button - though it comes into its own if I'm forced to use a busy main road at night.

I now have three "headlights" so I can experiment with different beam patterns.

Low Beam

The broad optic lamp (described by the supplier as "40 degrees") has proved inadequate by itself as a dip beam - though it has a pleasant smoothness provided by the diffused lens - it's a bit of a luxury as it puts much too much light directly in front of the bike, and duplicates the 48 LED lamp's downward spill to a certain extent - but comes into its own when that lamp is off, or dimmed.

AWAITING PHOTO

The intermediate ("25 degree") lamp which has another type of lens - concave with concentric rings has turned out to be not very different to the "40 degree" one - just a slightly messy beam, but it does reach a bit further..

AWAITING PHOTO

The two together do a decent job of lighting the way on unlit paths when oncoming riders prevent the use of the high beam, but some more tweaking of the beam is still needed.

High Beam

The narrow clear optic lamp (labelled "15 degrees") has a somewhat messy beam with a lot of side spill, but that doesn't matter much in a high beam, and it is more than sufficient for my needs - in that I don't have to slow down on unlit country roads when used in conjunction with the other two lamps.

I reckon I would need at least twice the light before being able to ride at daytime speeds in complete darkness on rough trails. That said, this 150 to 200 lumen lamp is perfectly adequate by any normal standards and upgrading it is not a high priority.

I will probably wait until someone makes a domestic lamp based on a 10 watt / 900 lumen Seoul P7 LED or three Cree XREs. At present prices the parts would cost me well over £60.

As a comparison, a 65 watt QH motorcycle headlamp produces in the order of 1500 lumens - 10 times the output of a Cree XRE and at least twice the output of a Seoul P7 - though it has to be borne in mind that I rarely achieve more than 25mph - and that's at least slightly downhill. ;-)

http://www.ledonline.co.uk/HP-MR16-1x5W-38-0.htm

Apart from the eternal problem of finding MR16 optics that can emulate a computer-designed headlamp, at £16 each (plus postage), these lamps are a lot cheaper and much less trouble than making your own housings and electronics.

They are specifically not "suitable for outdoor use" - certainly not for cycling into driving rain - the lenses aren't sealed and there are actually air vents in the sides - but I reckon the plumbing fittings I'm using provide adequate ventilation (vital - hence the extensive heat-sinking) whilst keeping the rain out .. and there is sufficient drainage.

I have had no problems so far after 12 months.

I managed to shear-off the pins on two of them by using screw terminals, so I opened them up and soldered on fly-leads - a worthwhile improvement in any case. I will also have to order a lot of different lenses to experiment with.

These annoyances aside, I like using domestic lamps. I will be able to use them at home if they ever get replaced by better ones. If they last the claimed 20,000 hours, they should see me safely to and from work for the next 266 winters !

I have been experimenting with hoods to reflect unwanted upwards light down onto the road where it's needed, and out of the eyes of oncoming cyclists - I'm hoping that I will eventually be able to trim the whole assembly down to a more acceptable size.

I have also added a dip switch, operable by the left thumb, to switch in the narrow "high" beam LED. It's a replica of the Lucas switches fitted to British motorcycles in the 60s and made to last. This makes a substantial difference - no more fumbling about for switches. £15 well spent. EBAY link.

I have connected the otherwise spare horn button to the 48 LED front lamp (via a small relay) for grabbing the attention of oncoming cyclists with dazzling lights - or none at all.

There are clearly various enhancements to be done - especially weatherproofing - initially probably going no further than a smear of plastic-friendly silicone grease, perhaps silicone roofing sealant - though I would hate to compromise the ventilation. I have over the years relied on "good drainage" and fairly frequent upgrading - though it pays to remember that they are permanently attached to my bike as I ride 45 miles every working week, plus another 50 miles on quite a few Sundays - which has to be a reasonable test.

Two years with inadequate drainage. The LEDs themselves would probably have lasted a couple of hundred years ...

I also ought to add a fuse ! The battery / charging connectors are starting to annoy me too - I'm thinking of car lighter sockets.

Bang !

As if to confirm what I had written, this is what happened when the 3 year old

charging connector fell apart and the wires shorted -

I thought my derailleur had smashed into my brand new rear wheel.

I fitted a new cell and all seems OK.

Summary.

Would I send someone out on the road with just the basic 48 LED lamps ?

Unreservedly yes ! I've never felt safer, and felt naked when my four year old battery let me down on one ride home and left me with only my spare lamps.

Lights alone are never enough - you need both defensive and assertive strategies to survive in traffic on a bike. I probably owe my own survival as much to 33 years of experience on 2, 3 and 4 wheels and as a pedestrian, thus allowing me to put myself in the other person's shoes, and, from my motorcycling days, expecting the unexpected at all times.

---------------------------------

Update early March 2011

The trend in domestic lamps has shifted towards triple LEDs in one package - it makes the electronics simpler. I have started experimenting with some lamps that are advertised as being "9 watts" - but pretty well all LED technology is hyped on EBay - they were advertised as "6 watts" last year. The first two I bought take 0.45 and 0.6 amps at 13 volts and also were missing screws and heat sink compound. They run very hot so I'm experimenting with sealing them so they can be used without housings. I reckon they look rather nifty. :-)

A second supplier quotes a current of 0.7 amps on their page - which means the LEDs can't possibly be consuming more than 8.4 watts. But even the 0.45 amp one (5 watts ?) does a decent job and gives me a very useful 30ish degree high beam in place of the previous 15 degree plus spill - which is excellent for overtaking static traffic in low light.

These lamps are also a lot cheaper than the previous 3 watt ones - under £10 each, and the beam pattern is more efficient than that provided by the 25 and 40 degree lamps I've been using in combination for low beam.

Update October 2017

The couple of miles each day that I spent on the Bristol to Bath path over a period of about 25 years or so used to be the highlight of my working day, but the massive increase in cyclist numbers has brought with it a seemingly disproportionate amount of bad behaviour such that I have moved my working day to try to avoid the worst of it - mostly young men with no care for others in the pursuit of their Tour Des Connards fantasies.

Along with the excessive speed and close passes, unfortunately has appeared insanely bright and often strobing bike lights - front and rear - which are now becoming the norm amongst those wearing high-viz as well as those wearing team kit.

It is a sad reflection on society ... A frequent combination is strobing lights and dark glasses, so to "mad, bad or sad", I have to add "stupid" as a possible explanation.

The whole experience has become very different from the "Dutch Experience" once espoused in Bristol.

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