Lucas Tail Lights

This post is going to start out as an attempt to unravel the mysteries of the Lucas MT110, MT211 and 480 tail lights, used from the 1930's through to the 1950's and I'm writing it to help me understand what's applicable to my Ariels. Looking at advertisements for these lamps, there's a bit of confusion & mis-labelling around the 211 and 480 styles abundant on the world's favourite auction site.

Here's some illustrations of original lamps I have collected over the past few months, together with a few notes on the differences between these lamps.

MT110

This is an original Lucas MT110, advertised recently on eBay.

Note how the mounting flange is part way along the lamp body - you have to reach behind the number plate to remove the bulb holder. The 211 and 480 bulb covers are removed from the other side of the number plate.

This lamp was used from the onset of electrical lighting systems in the mid 1920's, until 1950 - though it was not used on the military bikes, which had the smaller Lucas L-WD-MCT1.

Reproduction versions are available all over the interweb - an excellent one is found at www.vintage-replica.cz.

These use a BA15d bulb.

MT211

This is an original Lucas MT211, advertised recently on eBay.

The number plate window is missing from this one.

Here's the main difference between the 211 and the 480 - on the 211 the cover is retained with a bayonet fixing.

Good luck finding one of these lamps. The reproduction ones sold as MT211s are usually more like 480's - subtle differences and perfectly interchangeable but it confused me for a while!

These use a BA15d bulb.

480

This is an original Lucas 480, advertised recently on eBay.

You won't find this stamping on a reproduction lamp.

Here's the main difference between the 480 and the 211 - on the 480 the cover is retained with a flange fixing with three asymmetrical ears.

Lucas 480s were used for 1951 and 1952 Ariels.

What's really confusing is that reproduction versions of these lamps are usually sold as MT211 lamps. The upside is that they readily accommodate a BAY15d bulb, which offers the facility to have a brake light where none was originally available. Here's mine:

The bulb shown here is one of Paul Goff's LD6RST LEDs, and an excellent bub it is when fitted in my repro Lucas 529 rear lamp. Only problem is, at 43 mm long by 21 mm diameter it is a few millimetres too long for the bulb cover of a 480.

What you need for the 480 is a CDRC LED; mine is an EB1B. They come in 6 & 12V, positive and negative earth - so think before you order!

These fit perfectly in the tiny 480 bulb cover:

And here it is in place:

Catalogue

These 1957 Lucas catalogue pages show these lamps and others:

Interesting to note that by the time this list was published in 1957 Lucas were specifying the 529 tail lamp for all Ariel machines that had previously used the other, older lamps though it does not fit the rectangular pre-war number plate. My SQ4 uses a 529 - it fits in the same screw holes used by the older lamps and is hence a direct, and safer, replacement.

It's considerably less complex than the older lamps and was probably cheaper, so everyone wins.

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.