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.

Winter Work on the SQ4

It's time to think about winter jobs on the SQ4. The W/NG is the go-to bike and with no chrome makes an ideal machine for the winter, so if I can resist the temptation to tinker with it I can get on with the SQ4 and still have a bike to ride. The SQ4 jobs are:

1. Fix the speedo and get the blurred dial replaced
2. Get a new slow-running screw for the Solex
3. Remove the indicators - I have decided to do this, because they look awful and because the indicators are regular tungsten bulbs and the load causes the LED headlamp to flash with the indicators. This is a bit disconcerting at night...
4. Upgrade the headlight again
5. Replace the front wheel bearings with sealed bearings
6. Replace the front inner tube which leaks slowly
7. Look at the brakes again as they bed in
8. Make a new tool roll
9. Fit a couple of transfers
10. Change the oil tank for the one with a good filler neck thread
11. Make a lower chain guard

I'll make a separate post for the chain guard. It's here.

But first, checking the bike over reveals that the horn doesn't work. A quick nose about with the multimeter reveals no supply at the horn, so we look at the 15A horn fuse. This is blown, and was probably too low for the horn so we will change it for a 20A. This works fine and consistently, so we will leave this for now. We'll also pull the indicator circuit fuse...

I've stripped out the headlight, in preparation for sending the speedo away, uprating the headlamp and removing the indicators.The speedo has gone to Russell at Chronometric Instrument Services for a clean, new springs and a new face:

And here it is, back again just over a week later:

Soundly packed with lots of bubble wrap

New face, all numbers in correct positions

Guarantee sticker on the back

New screws and nuts

Now we can put the headlamp shell back in place with new bolts:

This is the new headlight bulb and it's driver:

It's from CDRC, like some other bulbs I have bought and is their 5th Generation LED headlamp bulb shown here. Not cheap, especially as to fit it I needed an H4 reflector which I bought from Paul Goff as usual. It's the 7" Lucas reflector with a pilot bulb. The bulb is very nicely made - aluminium, powder coated black with nice elastomeric seals and good quality connectors. I've chosen a 6V bulb, so that I can keep the ignition & generating systems running at 6V.

The bulb fits into an adapter ring, which is provided with the bulb. This allows you to twist the bulb through 360 degrees, offering left, right or central dip:

Whilst the bulb looks quite long it appears to fit into the SSU700 shell quite nicely. The cable goes off to the driver box which I will mount in the bottom of the shell.

All done and back together:

One job that wasn't on the list was to fix the offside fork leg which sticks down over large bumps. I pulled it apart to find that it was actually sticking with maybe a third of its total stroke left unused, so now that I have eased some very tight new bushes I am looking for better behaviour from the front suspension! I checked the other leg while I had most of it apart, which moved freely.

Lucas SSU700 Side Lamp Holder

A few pictures of the SSU700 Side Lamp Holder I made early on in the SQ4 rebuild.

I've fixed a LED sidelamp in it, from Paul Goff.

The bulb holder slides under two grooves cast into the underslung sidelamp housing, and is stopped by the two ears formed on the sidelamp holder:

In case anyone is interested, the Lucas part number is 516597...

This is a real one, from AOMCC member Lee Mallabone's KH:

Updating the rear light

One of the things I really liked about this W/NG was the pseudo Italian styling brought about as a result of its resurrection after the war - the red & black paint, the racy downswept bars, the white grips and the vintage style knee rubbers, and of course the rear light.

The rear light, whilst stylish in my eyes was equipped for two festoon type bulbs, and with a 40 W E3HM dynamo this was going to be a problem. In my experience it is easy to get a bright, low current LED for the back but using an LED in the front is less desirable, so, aiming to use my power budget in the front, we need an LED for the rear.

Now, since the light we have is a bit of a pancake (pork pie? cheese?) shape compared to the 529 on the Square Four or the Wipac 'Sabrina' on the Bantam, we can't use a regular bulb holder. In this case I'm going to use an LED light board which I bought from CDRC recently.

To use this we will need to remove the festoon bulb holders. This is as easy as drilling out the rivets:

I don't want to clean any of this up - I like the patina of the old light and the corrosion will not affect function in any way in this case.

So here's a simple group of components - the lens, case, back plate and LED board:

Since the area the rear light fits in the number plate is quite badly damaged, there is limited opportunity for fixing holes. I am going to use an existing one, but since any fastener in this hole will be inaccessible after the light board goes in, we must make it captive. I'll use a small coach bolt, fitted into a square hole in the light unit and retained with cyanoacrylate.

The LED board sits on two brass posts retained with M3 screws, so we need a couple of holes for them. Use a blanking plug to close the spare hole and a grommet to protect the wires.

The cables need to be restrained somehow, so that an inadvertent tug on the wires does not pull on the solder joint to the LED board. To do this, we'll use a tie-wrap to retain the wires to one of the brass posts supporting the light board:

And that's it. Here are a couple of views of the finished article, terminated with Japanese bullets: