SQ4 Chainguard again

After months of messing about, I have attacked the Square Four's lower chainguard again - mainly after having seen the proper version.

The thing I realised is that in about 1951 the pillion footrest hanger, to which the chainguard is attached, moved below the frame tube - all previous years have them above the frame tube and of course the chainguard bracket has to suit this arrangement.

Also in 1951 came the stop switch, mounted on the chainguard. The chainguard now looks like this, and it was used from 1951 right through to the end:

It's also much shorter than I previously had it.

What I hadn't bargained with was the effect this has on the brake rod. With the brake light switch mounted in that position, clearance to the brake rod is minimal if indeed there is any clearance. I already had issues with the brake rod, which was running in as straight a path as possible; those of you with Square Fours (prior to the arrival of the brake cable) know that this area is not very satisfactory - there is little room between the stirrup and the brake plate, and the chain adjuster is on there too.

No, the only answer is to bend the brake rod more than desirable and a few hours with the mighty Rothenburger saw that happen. Some pictures:

Straight run past the chain adjuster

Kink around the adjuster and over the stirrup

Significant bend toward the lever

So there you have it - the grey primer shows you that this is not finalised yet and I am none too happy with the rear brake - of course the bend in the rod has introduced a lot more play in the pedal before the brake engages. I might try this again...

Out and about on the W/NG

For the record, I put the CDRC headlamp bulb back in the W/NG:

High beam:

Dip beam:

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:

Rear End Styling

To me, it always seems a bit of a shame when someone fits a non-period part to a bike that affects the style of it, but sometimes its unavoidable and its only a matter of taste anyway.

One of the things that really appealed to me about this W/NG is that its a unique bike in that it has I think a very Italian flavour to it, despite being a more of less stock W/NG:

Of course, bringing it from Italy it needs to have a UK number plate adding at some point, and the existing Italian style rear light is in poor shape, as is the number plate:

Having looked at a few Guzzi Falcone rear lights, this definitely looks period Italian

I'm inclined to restore this cheapo aftermarket rear light and keep the rear end as-is, but I could fit a period civilian Ariel number plate with an MT110 or similar. The number plate looks very old, so it would be ashame to change it - though obviously the Italian number plate has to go.

Brake Light Switch

The devil is in the detail, they say. Casting around for small jobs, I realised that I had nowhere to mount the brake light switch. I knew from studying the wiring diagrams that Ariel began fitting brake lights to Square Fours around 1953, so that early Mk 2s would have factory fitted switches.

A plea on the AOMCC forum yielded this picture, from Greg Snyder in Pennsylvania, USA:

Greg also posted this, of the bracket in situ on his bike:

So, with guidance like that it was easy to make a new one:

Here are some details. Sorry about the sawdust:

And some more views: