Dry Build - Fitting the Swinging Arm

Next, it's time to fit the swinging arm and understand how the FERC fits around it.

At first, I struggled to get it in at all. It's difficult because the frame tubes behind the swinging arm mount are more narrow than the width of the swinging arm...

The secret is to lift the frame at the rear, drop the swinging arm and come at it from underneath, with the swinging arm cocked over so the offside is higher than the nearside. Once you get the nearside more or less adjacent to the nearside mount, the offside will rotate up into place. This works because there is more space in front of the offside swing arm mount - the gearbox interrupts the nearside.

I made a decision about the bushes - Steve Carter, marathon FH rider from the AOMCC changed his rubber bushes for a pair of oilite bushes and a much larger swinging arm spindle, and I am going to replicate that approach. Those bushes have a reputation for being a bit of a pig to remove. I thought I would try a hole saw, between the two metal tubes and sawing only through the rubber. It worked fine, with a bit of silicone grease to prevent burning but ultimately my saw was too short:

I resorted to the more traditional approach - a twist drill:

This works very well and of course if sufficiently long will cut all the way along the length of the bush:

The next job of course is to remove the outer sleeves from those 'SilentBloc' bushes. Easier said than done.

My first thought was to weld a plate across the sleeve and drive the whole lot out. I got a decent weld, and then proceed to drift it out - and tore the weld out with the plate attached. The sleeve stayed in the swinging arm.

The Dremel is a more traditional approach and works a treat. I cut a slot in one with a burr; the burr was ruined, but cut one slot before it passed away.

Once you have the slot cut, you can prise the sleeve out of contact and it will be loose enough to drift out.

First battle won.

From the Archives

Pathé News was a producer of newsreels and documentaries from 1910 until 1970 in the United Kingdom. Its founder, Charles Pathé, was a pioneer of moving pictures in the silent era.

Its roots lie in Paris when in 1896 Société Pathé Frères was founded by Charles Pathé and his brothers, who pioneered the development of the moving image. Charles Pathé adopted the national emblem of France, the cockerel, as the trademark for his company. After the company, now called Compagnie Générale des Éstablissements Pathé Frère Phonographes & Cinématographes, invented the cinema newsreel with Pathé-Journal, French Pathé began its newsreel in 1908 and opened a newsreel office in London's Wardour Street in 1910. Wardour Street, in Soho, was to become a centre of Britain's film industry. In 1958, Pathé was sold to Warner Bros. and became Warner-Pathé. Pathé eventually stopped producing the cinema newsreel in February 1970; by that time, many homes had their own or rented televisions and the days of the cinema news reel were over.

The Pathé News archive is known today as British Pathé. Its collection of news film and movies is fully digitised and available online and it's no surprise that that archive includes film of our favourite subject. You can do a search like this:

https://www.britishpathe.com/search/query/motorcycles

This famous film of Harry Perrey crossing the English Channel on a 1929 'Black' Ariel was made by Pathé and is here too:

https://www.youtube.com/watch?v=Wmbc3QSSyqA&feature=youtu.be

Harry was Competitions Manager at Ariel until 1930 and apparently, on arriving in France after a 7 hour trip, Perrey returned to dear old Blighty, on his Ariel, the same day!

In 2019, 90 years later AOMCC President Ariel Atzori will repeat the experience though in slightly warmer climes, on Lake Como during the 2019 Italian Ariel Rally.

Dry Build - Rear Brake Pedal & Bell Crank

Updated: first published 15th January 2019

Let's have a look at the brake pedal and crank arrangement next. Here's the crank in place - the rod is very rusty & I broke it trying to dismantle it...

The crank is held in place with a hex head screw (which I think is 5/16" CEI) and a large washer - both of which are missing. There's a clevis on the end of the brake cable.

I'd thought I might buy a new rod assembly from Acme, but having attacked the original with the wire wheel I see that much of it (rod aside) is in pretty good shape and would replate, so I have sat the broken bits in the vice with some Plus-Gas in them.

Drilling that broken rod out is going to be straightforward. Here's how I did it:

I decided to use the lathe to ensure that I drilled the broken std out on-centre. Since it was tricky to hold the banjo shaped swivel in the chuck, I made a simple collet out of a bit of aluminium round bar. The larger part of the swivel would sit behind the collet, which grips the parallel part.

I used the collet to hold the swivel in the 3 jaw chuck, and drilled the bit of broken rod out with progressively larger drills. I cleaned up the thread with a tap.

The rest of it cleaned up easily with the wire wheel. The bolt and washer used to retain the bell crank in the frame are missing - I understand (thanks to Mick D on the AOMCC Forum) that the bolt is 5/16" CEI, about 3/8" long. The thread needs cleaning up:

I've turned up a new washer from a bit of 25 mm 303 round bar:

Moving on, the brake pedal is all good and the spindle fits nicely into it's hole in the frame.

No idea why it is plated though. The spring, although it fits and is working, is very pitted and will need replacement:

I've made a new brake rod from a piece of 1/4" round bar. The collet chuck and tailstock die holder are very useful for jobs like this:

Here we go, new and old:

All fitted up. Next step is a new brake pedal spring and then the brake light switch.

Update:

The brake light switch fits onto a welded bracket on the frame down tube, right above the swinging arm, close to the abutment for the brake cable:

The brake cable uses a clevis arrangement to connect to the bell crank. This one is a bit long, and needs a washer and a split pin:

Barrels & Pistons

Let's have a look at the barrels and pistons again. some time back we had a preliminary look, but since everything is apart now we can make a more thorough examination and dimensional survey.

Armed with a bore gauge and a micrometer, we can do some measurements:

Parameter Transverse = parallel to crankshaft axis Longitudinal = parallel to motorcycle axis	Dim’n	Wear	Data Source	Position Number 1 – Drive side Number 2 – Timing Side
				Number 1	Number 2
Cylinder Bore upper transverse ¼” down from gasket face				2.821”	2.819”
Cylinder Bore upper longitudinal (A) ¼” down from gasket face				2.817”	2.817”
Cylinder Bore middle transverse 1” down from gasket face				2.816”	2.815”
Cylinder Bore middle longitudinal (B) 1” down from gasket face				2.813”	2.815”
Cylinder Bore lower transverse 2” down from gasket face				2.816”	2.816”
Cylinder Bore lower longitudinal (C) 2” down from gasket face				2.811”	2.813”
Piston (ring land area longitudinal) (A1)				2.793”	2.792”
Piston (ring land area clearance) (A-A1)				0.024”	0.025”
Piston (below rings longitudinal) (B1)				2.811”	2.812”
Piston (below rings clearance) (B-B1)		0.002” 0.004”	BSA Service Sheet 216	0.002”	0.003”
Piston (Extreme Skirt longitudinal) (C1)				2.813”	2.813”
Piston (Extreme Skirt clearance) (C-C1)		0.002” 0.004”	BSA Service Sheet 216	-0.002”	0.000”

All the rings were stuck so the pistons are away for a well earned soak in the parts washer. I'll leave this picture here so I don't forget where they are:

Little steps: Horn Bracket for the FH

Back in January, before I started work on the crankshafts and before my little Grandchildren laid us out with those pre-school viruses they love to share, I was assembling the toolbox and some bits around it. I wrote about it here.

Workshop time for bikes often occurs as a distraction from something domestic you are supposed to be doing but have become tired of - or maybe I have a short attention span; so it was that yesterday found me building shelves for my off-grid battery bank and making a horn bracket while the glue dried.

You'll recall that I have a toolbox which may be too early for my FH. The bottom bracket looks like this

Ariel do not list a separate horn bracket for 1958 and here's why - the horn bolts directly to the toolbox tab as shown in MickD's picture below. As you can see, I don't have those holes on my toolbox! The swinging arm toolbox carried a -54 part number through to the end of four stroke production, so I must have an earlier incarnation of the same part, designed to be used with an Altette and not the Lucas HF1441 horn used in 1958.

I needed to make an intermediate bracket, or modify my toolbox. I have the correct Lucas HF1441, which I think came from eBay. It has a right angle bracket, retained to the multi-leaf horn bracket with two 2BA hex head screws:

As always with any sheet metal work, we mock up the required part in cardboard and test it for fit:

Then, with some Dykem marking blue we can lay it out on a bit of 4mm sheet. It's hard to see with the lighting, but I have punched witness marks around the perimeter of the part to help me see the shape during the filing & linishing that will happen later:

Cut out commences with the hacksaw, and carries on with files and the linisher - a very useful tool that I acquired recently.

The holes were actually drilled while the part was still square - so that it could be clamped securely in the machine vice on the drill press:

Test fit - good to go to paint I think, though it's very close to the upturn on the toolbox bracket. I'll need to deal with that as the toolbox may get powder coated.

Welding Nuts

As you will know, the swinging arm Ariels make use of Spire fasteners and matching screws in various places, which look a lot like blunt self tappers. These appear in the rear mudguard and the seat base. Additionally, the bikes use captive nuts in sheet metal cages (I made one here) in the headlight and in the chainguard.

Of course, the captive nut in the chainguard was missing. I thought about making one, and having fiddled around for a while making a 5/16" one for the headlamp, I wasn't about to make a smaller (1/4") one for the chainguard that no-one would ever see, so I decided to weld a nut in.

Now the tab on the chainguard is not so large, and I wanted something larger than a conventional nut to weld to, and secondly I wanted to make sure the thread was in the centre of the square hole in the chainguard, so I came up with a special nut, designed to be welded in:

It's turned up from a piece of 3/4" round bar on the lathe:

It's got a 0.35" diameter journal to fit into the hole, and a lead in chamfer to a 1/4" BSCy thread:

The back is also chamfered, to allow me to make a fillet weld easily:

I'll make some 5/16" ones for the mudguard and seat.

Square Four - Improving the mixture

 I learned from the folk on the AOMCC forum that the mixture can be adjusted by changing the float level, as in other carburetters. I hadn't thought of this approach with the Solex because the float acts directly on the valve and there is no arm to bend, for example.

However, the collective consciousness revealed that the float valves could be fitted with several washers if necessary, to lower the valve and hence the fuel level, leaning out the mixture. Like many others, I had replaced the fuel valve fibre washer when I rebuilt the carb, with a single washer of about 1 mm thickness, but apparently there can be up to 3 mm of thickness there.

Since my bike was using quite a lot of fuel and, judging by the state of the silencers was clearly running rich, I added a second washer. 

A plug chop revealed that the change had been a success. Previously, I had been running NGK B5HS plugs as my B6HS, equivalent to standard fitment, had been sooty. After the washer was added, I was able to revert to the B6HS and they were a much better colour.

Speedo Gearbox - W/NG

Since I've had my W/NG, I've been suspicious of the fact that it is (or was) little faster than my Bantam, struggling to reach 50 mph without a wind behind it.

A W/NG with the wind behind it

So, I was interested in a thread on the AOMCC forum on the subject, in which fellow W/NG rider Alan Moore wrote:

"Calculating the required ratio to give 1600 revolutions per mile traveled by the front tyre (with the 43T/14T hub gears) results in a required gearbox ratio of 8:12 (it reduces the input turns by that ratio). So the input pinion has 8 teeth and the output pinion 12. So my 8:14 ratio is a little bit out and gives 1400 revs per mile which means the speedo would under read by about 12%"

I'd been out for a 56 mile run (Google maps) and recorded only 49.6 on the odometer. Watching the town speed warnings (the ones that flash your speed up) it appeared that the speedo under reads by about 12%, so I was immediately suspicious that my speedo gearbox gearing was wrong too. The fact that both speed and distance readings were out proved that this was not a speedo head calibration problem - which would have been a surprise, as the speedo head was shown to be very accurate when it was rebuilt.

It took me a long while (and quite a lot of money) to find a speedo gearbox with the right ratio. I'm hoping to be able to recoup the cost by selling the old one.

So onto fitting it. I'm always happy at the way these old bikes facilitate maintenance - it's so easy to pull the front wheel out with the bike on the front stand. Here's the speedo gearbox:

And here's the small pinion inside the brake plate. You have to remove the split pin and the pinion to get the gearbox off:

There's a bit of debris here, and some damage on the small pinion. I'm not sure the two internal pinions are mating properly.

Once you have undone the large locknut, you can unscrew the speedo gearbox. You'll see this split pin underneath the driven gear - remove the split pin and you can tap out the gear using a drift. It will drive out the cap:

The cap with the grease nipple is staked in, but will come out if you gently tap the driving pinion. You can now inspect all the components, clean and grease them before reassembly using a new split pin.

By the way, this is a different gearbox. Not my damage!

Charlie's Shed - Fuel Tap Plungers

If you find yourself short of plungers, or the shaft of your adjustable plunger is damaged, they are quite easily made if you have access to a lathe.

The brass centre of the adjustable plungers, which is often short from having the slotted end broken, can be made from a bit of 3/8" round bar. Chuck this in the lathe and turn a suitable length to 5/32" - the best way to do this is to turn an 1/8" or so to exactly the right diameter, then use this short length as a guide to turn the rest in one pass. With a sharp tool this shouldn't be too much of a problem and it avoids the tiny bar bending away from the tool, which will result in the outside diameter being over size.

Chamfer the end and cut the thread - it's 5/32" BSW. Make sure you use a tailstock die holder or back the die holder up with the tailstock to keep it square - you don't want that thread wandering off.

Give it a polish and part it off:

Assemble it into the plunger and you are done:

The shaft I have made here is a bit over-length compared to the old one - maybe I will adjust it a tad. Notice the diamond knurl. I don't have the cutters for that - straight and diagonal knurls yes, but not the 'inverted' diamond knurl. Rather nice, and easier on the hands...

Post war plungers, as I mentioned in my other post on the subject, are non-adjustable unlike their prewar forefathers, and because of this I think it makes sense to update them with an O-ring seal.

The hexagon reserve plungers are made from 0.600" 303 stainless steel hexagon bar. You'll need a decent length for chucking and for the milling operation. Chuck the bar with a couple of diameters showing beyond the jaws, to give you enough space to part off when you are done:

Turn the shank to the required diameter - a little over 5/16". This needs to be a loosish clearance fit in the tap body you just reamed.

Use a thin parting tool to form the O ring grooves. Space them so that they are at either end of the equivalent length of cork:

For those, like me, without a mill you can use the toolpost or a milling attachment to mill a 3/32" slot, about 1/16" deep in the tap shank. Since the loads involved in this operation are tiny, I didn't bother to set the lathe up for milling. I cut the slot at about 1500 rpm in two passes, with a 3/32" slot drill.

Once you have completed the milling, test the plunger in the body and make sure the plunger slides freely with the retaining screw in place. Next, put the bar back in the chuck and polish up the shank; then, before you part off, turn the shallow chamfer on the inside of the head. You can then part off.

Turn the plunger in the chuck, and skim the outside face of the head, cutting the shallow chamfer in the same setting. Polish the head and you are done.

And watch out - the reason that slot looks slightly ragged is because I broke a cutter in it. Go easy.

Next thing - you will want to smooth the edge of the ports in the tap. look at this:

See the sharp edges? Remove that with a burr in the Dremel, or a tiny grinding tool. If you leave it, the O ring will be damaged. Look:

That nick will cause a leak. You are not really supposed to use O rings in dynamic applications like this.

Thanks for reading, and I hope you found it useful.