2012-03-17 06.31.56

Ever wondered what the world looked like at night beyond the yellow glare of the street-lamps? Now’s the time to find out and even for the let’s-keep-everything-original (well, original looking, anyway) buffs, here is a low-profile change that could save your life or someone that you love (no-one else gets to ride the bike, rest assured!)

So the old Miller candle-in-a-beer-bottle headlamp might look super-duper, but it’s not much practical use, unless you subscribe to the old idea of having someone walk ahead of you waving a red flag (no longer compulsory, by the way!).

Even with the frosted or ‘cat’s-eye’ lenses, help is at hand. I realise that 90% of the owners of pre-war motorcycles of ANY make will probably scoff at the idea (preposterous!) of riding at night, BUT, even then bikes were intended to do just that, imagine!

SO, while the frame and other bits are being painted, I got sort of withdrawal-symptoms and just had to get on with something… I had already split the crank-case open (another story…) and the box of electrics on the floor under the bench was strangely tempting! Actually before I took the things to the painter was when I got started, as the headlamp shell was also important. What if the conversion didn’t fit??

Don’t worry, it does, and no one would know the difference, until you turn the light on, that is, day or night! And as much as I can understand many folks’ trepidation at running at night with their precious vintage/classic, being seen in the daytime is difficult enough, when all the other bikes have their headlamps on (and STILL get ‘overseen’ by other motorists…), so it is still madness to drive without lights on even in the daytime.

This is one reason that I advocate at least a beefed-up dynamo and 12 Volt-electrics if you are going to do anything like ‘normal’ running during the day, (since most six-volt systems simply are not ‘up to it’) as well as improved brakes, as without them, you are certainly risking your life in the density of today’s traffic.

Back to the conversion. I acquired a reproduction 8” reflector and ‘cat’s-eye’ lens on the internet. They seem suddenly to be available, so I wasn’t going to slice up any ‘original’ kit for this experiment!

And yes, I know, there are 35W Halogen bulbs with the ‘right’ fitting for the old reflector units, but to be honest, they are not much better than the originals, though they do last longer, but they also need 12V electrics.

Anyway, I had decided to go this path a long time ago and have already converted my old Ariel to run un HIDs, as I used it daily in Germany, where it is dark most of the day in winter, certainly on the way into and back from work…

The first thing I needed was a ‘donor’ mounting for the new bulb, which has the normal Halogen lightbulb fitting…off to the breaker’s to find anything with a suitable bit. I was lucky and found one that looked just right and would be easy to take off and even modify if necessary. Just physically getting the bulb in the reflector is not all you have to think about: what about focus and spread? The light has to be dippable enough not to blind oncoming traffic, even at night, which at this brightness (six times that of an equivalent Wattage of Halogen) could be an issue, no?

Here is what I went for, a no-name square headlight:

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Conveniently, the fitting is in two parts and the reflector is metal, so no problem to trim around it with an angle-grinder with a very thin cutting-off disk, as the picture above shows. Taking care to note which way is up on the fitting, it gets removed and de-burred and laid aside, while the ‘Miller’ unit is attended to, much in the same manner, but not quite as drastically!

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Trimmed around…

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Cut off and deburred

The pictures are taken with my ‘phone, so you’ll just have to put up with the poor quality… What you see here is not quite how it ended up, as I shall explain later: Suffice to say that I took the whole ring off eventually, and even had to enlarge the resulting hole a bit to get the other part to fit snugly. I only mention it now, because it will, of course, depend on what actual fittings you end up getting from the scrappy!

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Here you can see the ‘new’ fitting tried on the reflector for size and for the moment all is well, though the bulb itself looked pretty deep, too deep to fit in the shell??

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The Halogen looks good and the fitting wasn’t too distorted, so all went well, next the HID thingy…

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Whoops! That’s a lot taller! It does fit, though, at this stage only just…

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A real tight squeeze, as it ‘appens, the headlamp rim had to be ‘persuaded’ to close all round.

Oh, that was something else I wanted to say! The shell is an original miller, the rim I got off e-Bay from the ‘States… Quite nice looking, but mine was a bit small in diameter, so the material could have been cut a bit longer before joining into a ring, so it had to be ‘fettled’ to fit. The inside of the back is turned over in the usual manner to allow the protrusions on the shell to grip it at the top. This reverse turn-back lip had to be flattened almost completely against the outside before it could be made to go over the outside of the headlamp-shell, otherwise it was fine.

Back to the story… Thankfully the shell held the HID into the socket and I set up for testing…

OOPS! When dipped, the beam lit the TOP-half of the garage doors (my highly-developed, repeatable-experimentation-area), which was sort of wrong and not what I expected. The Registration and Road-Safety-Testing people would also probably not like that very much, either! Hm, what to do now??

As remember, if I move the light-source further forward and INTO the reflector, the beam should narrow, so at least that would be an improvement!

Off with the whole caboodle and try to modify the socket to let the bulb in deeper… That is the reason, by the way, for removing the original ring completely and enlarging the hole slightly, as I touched on earlier: This allowed, especially after I had also cut the slots deeper in the socket for the ‘wings’ on the bulb itself, the whole thing to sit better and further into the reflector (and left more space inside the back of the headlamp-shell!).

After a bit of experimenting, I actually ended up putting it in as deep as was possible for this fitting/reflector combination, and was so ‘right’ that the low-beam ‘flipped’ from upper-half to lower-half illumination, the main-beam being unaffected, just a bit more concentrated, as in the pictures that follow.

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An almost frighteningly worthwhile exercise, with the lamp at about the right height and pointing (for real road use a bit higher than normal) as good as straight ahead.

Final positioning done, the fitting is fixed on the back of the reflector-shell using clear RTV Silicone: if the hole in the back of the reflector is approximately round and of the right size (actually not at all difficult, nor particularly critical…just has to be big enough to accept the fitting INCLUDING the bulb!), then it all fits very snugly and should not move while laid aside for 24 hours to cure. Being a belt-and-braces-man, I also held it all in place with some tape diagonally stretched over the back. When cured, this should never come off, as the ‘footprint’ I left on the fitting should be ample to give an adequate surface area for bonding of the two parts forever!

This bulb has the ‘normal’ colour temperature for Halogens, so about 4300°K, which is still a bit high for my liking (a bit too ‘white’, though not yet tending to blue), and I eagerly await the first batch of special 3800°K bulbs (‘straw’-colour, to match the older bikes a bit better) which are being made to order for me. They are 35W items, which, as I think I said before, push out six times the candle-power that a 55W halogen does… Not bad, eh!?

Cost of the exercise? The halogen lamp from the scrappy cost me $15 and the HID conversion per se will cost around $100 (I just ‘happened’ to have one lying around at home…).

All-in-all, pretty good for a life-saving and yet indiscernible modification!

I see it like this…it’s very similar to the ‘helmet’ issue. How much is what you have between your ears worth? (not to mention your face/chin etc) If you’ve got a ten bob head, get a ten bob helmet, but I know how much I spent on my last (SHOEI full-face) helmet, which I also ride on the pre-war bike. (Helmet ‘design’ by me, the reflective foils used in the traffic-sign-industry being cut out and stuck on by hand… I do insist on ‘passive’ visibility at night, too!)

Not so ‘in keeping’ with the era, but in the event of an accident will hopefully do a better job of in-keeping my brains than that stylish ‘corker’ I still have…

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