Tuesday, 16 January 2018

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.

Sunday, 14 January 2018

SQ4 Chainguard

A while back, I made a post in which I converted a Anstey-frame single cylinder lower chain guard into a rigid frame one for my W/NG - and I also spoke about making one for the SQ4.

I had a rigid frame chain guard for a SQ4, which I was planning to convert but I have since been approach by someone who needs just that, so I plan to make a Anstey Frame chain guard from scratch.

I have the rear bracket spare from the one I used for the W/NG, so I just have to make the front bracket and the guard itself which I will copy from the rigid frame version... Simples!

Here's a 'patinated' sheet of 18 SWG cold rolled sheet, juts like the original was made from all those years ago.

Using a tape on the original guard, we find that it is 13 cm wide, so we mark a suitable strip on the sheet and draw around the original with a spirit marker:

The old jig saw makes short work of cutting it out:

Next up, bending up. I'm using a piece of timber as a bending 'iron' here, it has a radius planed into the edge to mimic that of the original chain guard, and the flat side of the guard is clamped securely to the board:

You can bend a piece of 18 SWG this size by hand, and the fact that the board is more narrow than the chain guard's final width means you can over-bend it a little, to finish at the required 90 degree angle:

With the first bend done, we can swap sides and make the second bend in the same way. This is possible, but more difficult to bend by hand because of course we have much less length to lever with. Turns out OK though, but there are a few adjustments needed to align the ends:

Here's a view from underneath of the guard and the front mounting point looking up at the chain oiler channel. At this point in time, the guard needed some adjustment to the width:

Here's the other end:

And the point where the rear mount will go:

And the front mount, from the outside:

Tacked up and trial fitted:

Clearance looks adequate, though some adjustment might be required at the front:

With welding complete, I've used my favourite U-Pol etch primer on the chainguard:

And U-Pol gloss black:

And fitted:

As a small post script to this, the chain guard came off again a few weeks later as the chain was rubbing on it. 70 odd miles did this:

I recreated the unsightly bends (that I had taken to be damage) from the original, adjusted the rear bracket so it sat a little higher and it no longer rubs.

For the record, the chainguard now looks like this: