Headlamp Rims & Glasses

As part of the winter lighting upgrade I had to change the original, rusty BPF reflector to a H4 fit reflector to suit the new bulb; I bought this from Paul Goff and all was well, until I came to fit the rim to the shell and found a very tight fit - much worse than normal.

Pushing too hard, I cracked the new glass: £35 down the drain.

However, after the event I realised that I wasn't too happy with losing the old Lucas BPF glass, with the Lucas logo in the middle and that actually this was a blessing in disguise, though it might not enhance my beam pattern too well. I decided to replace the broken glass with the old one, that I would extract from the original rusty reflector.

I started with the spun edge of the reflector here:

And I introduced it to the bench grinder, removing the metal until I broke through the fold:

The spun edge of the rim could then be prised off and the old glass released. You can see the poor condition of the silvering:

The glass was in need of a clean, but otherwise came through the process unscathed:

The new reflector had the rest of the broken glass removed, by pushing the glass out with a metal bar through the bulb hole and by removing the edges with pliers. The glass is held in with a relatively soft mastic which you can cut easily, and if you are trying to remove a modern glass and keep it whole you can cut the mastic around the glass, and then lift the edge of the reflector off the glass at a small slot in the reflector (seen on the far side of the picture). You can get a small screwdriver in here and start the removal process:

I used a similar product to put the new glass back in:

Getting the rim on was still a challenge. I removed most of the new paint from the edge of the shell; made sure both the rim and shell were circular; fitted the rim without the lamp unit and checked clearances for the W clips around the rim.

It was not until someone suggested greasing the shell (thanks Les!) that it went on - a bit of silicone grease on the rim had it slipping on easily.

Unloading your dynamo - and updating your lights

A year ago I replaced most of my bulbs with LEDs, if you remember my 'Dusky Jaunt' around Norfolk. I changed all the lamps, except the headlamp to LEDs; the headlamp became a 35W/35W halogen.

Since then I have become aware of LED headlamps in BPF packages. I got this one from Classic Dynamo & Regulator Conversions.

Now, as the electrical engineers among you will realise that the 35W headlamp is about half the output from my C35SD dynamo, which gives something like 70W at full output and balances charge at 40 mph with the headlamp on. The SQ4 currently runs a 6V halogen, which looks like this on the road:

Low Beam

 You'll note the white LED in the speedo! Here's the halogen again:

High Beam

Now, 35W at 6 V is about 6 A. This little chap passes 0.52 A on low beam and 1.04 A on high beam (which actually leaves both LEDs on, doubling the current and the light output) and you get:

A crisp, white light with an excellent beam pattern that will change your night time driving experience.

The result is that the ammeter hardly moves with the headlights on, and I should be able to drive around all day with the lights on.

As you can see in the picture, it is a nice robust construction and there are no filaments to blow and no fragile glass envelopes. In addition, each bulb will work on both 6v and 12v systems (one bulb suits both voltages), so if I convert to 12V at any time I don't need to change this bulb.

You can get negative and positive earth versions of these bulbs. This is how it looks on the road:

Low Beam

 Looking at the high beam picture, you will see that the bulb is arranged to light both the low beam LED and the high beam LED when switched to high beam:

High Beam

The second modification I am going to make is to replace the twin festoon lamps in the W/NGs Italianesque rear lamp with the LED lightboard I bought at the same time.