FH - insecure centre stand

 Some while back I wrote about adjusting the stops on the centre stand to get the wheel off the ground and to enable the bike to roll on and to roll off the centre stand relatively easily. A few months using the bike has made me realise that it's far too easy for the bike to come off the stand and since my son has had it he's remarked on it a couple of times.

I need to do something about this. 

I recall that when I bought the shock absorbers I was encouraged by fellow riders to go for a longer shock absorber option to make the bike easier to get on and off the stand, which it does. The bike is actually fitted with 310 mm shock absorbers - the standard is 300 mm, or more probably 12 3/4".

Stripping one of the shock absorbers finds an M10 by 1.25 pitch thread on the damper. An option would be to increase the length of this thread and then chop the excess 10 mm of the end of the damper rod. This won't be too much of a problem except that I don't have the suitable die and if I can't remove the rod from the damper I will have to cut the thread with the die but leave no undercut which will be untidy. I can't remove the rod from the damper, because the top of the cylinder is rolled over.

My first step was to ask the supplier if I can buy the damper units without the rest of the shock absorber, and these turned up for about half the cost of a new set:

The next step - and it's never straightforward is it - is to modify the spring compressor. The problem is that the compressor now has to reach so far down inside the spring (because the damper is shorter) that I can't get the pin in through the damper eye. 

I sorted that out by chopping one end of the pin off, trimming the end and welding a washer on the end to act as a head. 

Next I rebuilt the shock absorber and then turned my attention to the other. With that done I could remove the centre stand and adjust the stops. There's not much to see with this operation apart from my grubbing knees elbows and nose. Doing this job on the side stand is ok for the right hand side of the centre stand but getting to the left is very difficult, especially when the temperature is in 30s!

I ended up taking 1/16" off both stops which resulted in a bike that needed more effort to get off the centre stand. I noticed that the stand feet are wearing already and will need some attention in the next year or two.

Model A - crankshaft shock absorber 3

 Well thanks to Karol of the Slovak Ariel Klub I now have the parts to put the crankshaft shock absorber back together. Here is the illustration in the parts book:

I think that what Karol has designed & manufactured is an adaptation of what Ariel designed. What is shown in the parts book as A6/712 (the 'sliding member') fits inside A6/715 (the 'spring retaining collar) which was possibly easier to make at the time. What Karol has provided I think is a combined part including the features of both of these parts as shown on the left in the picture below:

You can see it assembled here and inspection will tell you that this will work perfectly well. The new part sits in the spring, but also slides on the mainshaft - there is no need for these to be separate parts:

Clearly I've only got one nut fitted here but there's no need to put the second one on at this point. Some digging around in the end of the crankshaft reveals a grease path and a thread for a grease nipple which I've fitted here:

There's not much more to say about this bit other than that until I bolt it up finally we will leave it as it is.

Model A - crankshaft shock absorber 2

 Well the Lambretta cush drive spring has arrived and fitting it up you can see why AOMCC singles expert Peter said that it wouldn't fit with the '26-'27 pattern shock absorber, which is what I have here. There is no way that you can get the nuts on to start this compressing the spring.

Fortunately, the 1930 pattern shock absorber is available from Karol Burger of the Slovak Ariel Klub.

Even more fortunate is the fact that Karol stocks two types of sprocket, one with 19 teeth and one with 23 teeth. What I have here is a '26-'27 19 tooth engine sprocket which is obviously for sidecar use: 

We know from experience with both the Huntmaster and the Square Four that bikes of this era are usually low geared (even when specified for solo use) so we do not want to compromise our budget and our riding experience by buying the wrong sprocket. This makes me feel a lot better about having the wrong crankshaft shock absorber!

We won't do anything else in this area until we have the new bits from the Slovak Klub.

Model A - crankshaft shock absorber 1

 It's all go here. The latest investigation is to look at the crankshaft shock absorber, which it turns out is missing a few vital parts!

These are the sections of the parts book that deal with the crankshaft shock absorber. I had assumed, wrongly, that because there was a shock absorber in the clutch there would not be one on the crankshaft. However club member and Black Ariel spares coordinator Lee, who is currently restoring a 1928 Model E (which has a Burman box) tells me that his bike has a shock absorber in the clutch as well. Therefore I am now given to believe that all the bikes have a crankshaft shock absorber.

I'm missing the spring and both the collars that it sits in. I'm told that a Lambretta spring may be useful and I have a dimensions for that and I actually I have ordered one. 

The spring collar A6/714 is missing and I have no picture at the moment. However the function of these parts is fairly obvious so I'm confident that I can make something up.

This is the bit that Sturmey Archer call the spring retaining collar. It's listed at Draganfly but unfortunately out of stock at the moment. I'm sure we can make one of these.

This is the A6/712 sliding member:

As you can see, the spring sits on a 33 mm diameter. The Lambretta spring dimensions are:

• Free length = 37.5mm
• ID = 35mm
• Wire dimeter = 6.85mm

The diameter should fit nicely. It looks like this:

As you can see, there is only two wire diameters in that 37 mm length, so it should compress considerably - maybe to the 20 mm I have available!

FH - engine sprocket

 With Mrs H on the couch, asleep after a busy morning on the allotment I decided to do some shopping and on the way back get a bit of time in the workshop. After finishing measuring all the timing cover screws I decided it was time to change the engine sprocket.

Regular readers will know that I realised after riding the bike that the gearing was very low, and inspection of the pictures revealed that I had a 22 tooth engine sprocket: for solo use, I should have a 24 tooth engine sprocket. The Siamese pipe that came with the kit is another clue to the bike's history with a sidecar!

Pulling the primary case apart is a pretty straightforward exercise, if messy. I thought the case was empty of oil, assuming it had all been thrown out - in fact, the drain hole was blocked with red Hermetite and removing the plug had no effect - so it all ended up on the bench...

The primary chain has 74 pitches. A lot of adjustment of both chains had the gearbox in a suitable position for the new sprocket to go on. Note to self - for the future, using a socket and the slim plastic 3/8" ratchet drive on the primary chain adjuster makes it relatively quick to move the gearbox. 

Here it is in place:

I noticed that at some point in the dim and distant past the primary chain must have got very loose because the cast lug for the primary case screw right under the sprocket was very worn to the extent that oil would leak into the screw hole. I refitted the screw with a fibre washer. Incidentally, rather than use the large gasket with Wellseal I sealed the primary case with Threebond 1215 and no gasket.

These things are so easy to work on. I'd been considering whether to tackle this job before I rode the bike again thinking that I didn't want to have it off the road for too long but actually this kind of thing only takes a couple of hours. I hate to think how long it would take on a modern bike - but then you probably wouldn't have to do it in the first place! 

That's it all back together again a couple of days later:

FH - shaking down 1

 Well, I've decided that since in the last nine miles of circuits around the house the Huntmaster hasn't exploded, I have today filled it up and racked up another 15 miles.

Amongst other places, we've been to the lovely 1901 Weybourne Station on the North Norfolk Railway. Here the FH poses next to the 1960 - built English Electric Class 37, ready to depart on the last up-train of the day.

It's going very well. In the first nine miles I had adjusted the brakes 3-4 times, and after changing one of the levers they are starting to feel OK. 

Some days ago, I had adjusted the tickover. Today, having put perhaps 11 miles on the engine I stopped at Weybourne to find that it was less easy to start; adjusting it on arrival at home, I leaned it out 1/2 turn or more - the plugs are showing tickover was rich. I may have gone too far, but before I adjusted it the engine was very easy to start cold.

The other thing that is obviously wrong is the gearing - you can feel it is too low. Inspection of the build pictures show there's a 22 tooth engine sprocket fitted - standard fitment for solo bikes is 24, so we will have to see if we can get one of those.

Lastly, we have a timing cover oil leak and a primary case oil leak. I know that the old chain oiler screw hole is open, and there may well be too much oil in the primary case but since that will have to come apart to fit the new sprocket, we won't worry too much. The timing case is another matter.

FH - primary case

 I've bought (from Simply Bearings) and fitted a new spring link to the primary chain, tensioned it, bolted the gearbox up tight and finished the crankshaft shock absorber.

I spragged the sprockets like this:

There's definitely a split pin in the crankshaft shock absorber nut!

FH - preparing the primary drive

There are a lot of work faces appearing on the bike now the cylinder head is ready to go on; the timing side can be assembled once the automatic timing device is finished and the primary side can have the clutch fitted and the primary chain built up. For no particular reason I've elected to start on the primary side mainly because I don't have the bench space at the moment to do the ATC. Here I've fitted the 19 tooth standard gearbox sprocket with a spare secondary chain and torqued up the big nut.

 

The spare length of chain I had knocking about was too short so I've taken this unusual approach of wiring it through the holes in the sprocket just to allow me to use the back brake to tighten up the gearbox sprocket nut.

With that done we can start looking at fitting the inner primary case half. What's different about this bike is that it's fitted with the fully enclosed rear chain case (FERC) something I have not yet experienced on an Ariel. There are a couple of unusual mounting points, one of which is this nut which is attached to the front half of the FERC.

It's a 1/4 in CEI bolt which needs a special tab washer to retain it to the inner primary chain case casting and to prevent it coming undone, dropping into your primary drive. The special lock washer is available from Draganfly but unfortunately I forgot to order one. I've made this one out of a piece of 0.9 mm sheet steel.

Here it is with the bolt tight and the tab washer folded up.

For the record I have fitted that 1/4" BSW screw with low strength threadlock from Loctite. The castellated nut retaining the engine shaft shock absorber will need a split pin to prevent it falling off.

That's it for now; the next step will be to think about the clutch. I expect to find some parts that are in need of replacement so I'll have a look at the clutch soon to get those on order.

For now, let's just record that I fitted a new length of primary chain and an old spring link just for now. I'll have to order a new one. 

The other thing to bear in mind is that the chainwheel is rubbing on the oil catcher so I'll have to sort that out before I put primary case outer cover on.

FH - Another painting update

 I’ve now collected the remaining painted bits, which are all the more complex parts with more preparation, transfers and a gloss coat. They look great.

Painter Damon has explained that I mustn’t leave the parts covered while the epoxy cures, so when I get it home I arrange the parts around the workshop or on the bike, as best I can:

The colour is Opel/Vauxhall Monza Red, as recommended by the club, and the tank is painted to a template provided by the Danish Ariel club.

To help assembly, I’ve ordered the shocks from NJB.

You get a flavour for what it’s going to look like:

FH - Forks, Steering Damper & Swinging Arm

 A few spare minutes found me progressing the build a bit further. Last night I ordered the engine parts from Draganfly; the pistons and big end shells have already arrived from the AOMCC Twin Spares chap. They look excellent:

You'll recall the swinging arm has solid bronze bushes in place of the standard metalastik bushes, so the first job is to fit an angled grease nipple pointed away from the FERC:

The swinging arm goes in easily and is bolted very loosely. It's held up with an old shock.

I've put the steering damper back in; the pin tapped in easily.

Now, I was careful to ask the painter to avoid grit blasting the oil tank, and he has indeed prepared that by hand. However, the fork sliders would have benefitted from blanking off as they are full of grit; I made this swab to clean them out:

Running paraffin down the slider in the cleaning bath I swabbed the grit out:

There's quite a bit - that was worth doing:

I cleaned the fork legs with 180 grit Scotchbrite - they are not very good:

I ordered a set of seals and new seal holders yesterday. At £115 a pair, it's worth buying a new set of hard-chromed stanchions as well.

W/NG - Primary drive & clutch assembly

Now that the engine is essentially finished, we can turn the whole bike round and reassemble the primary drive. There's not enough room in the workshop to get to both sides - there are five bikes, four of them Ariels, in here at the moment.

First job is to look at the inner case and to clean up the joint face. This is a close fit, but it does contain the primary chain oil so we will fit it with a dose of Threebond.

With the inner case fitted, we will add the single internal retaining screw with some Loctite 243. You don't want this coming out in service.

You'll note that the spacer behind the shock absorber is already fitted, so we can grease the mainshaft ready for the shock absorber:

Next comes the sprocket and the splined half of the shock absorber. These look odd and confuse people because the outer half of the cam is much bigger than the inner half, and it looks like you have a mismatch of parts. Don't worry, it is supposed to look like that on an Ariel single.

Next comes the spring, cap and the first nut, followed by the special lock washer:

Then comes the second nut. The tabs on the lock washer bend alternately over the inner and outer nuts.

In the previous picture I had test fitted the clutch sprocket only to find that it was making a rubbing sound. That turned out to be this homemade oil trap and the rivets holding it in place:

You can see the witness marks on the back of the sprocket. I pushed the offending part of the aluminium ring towards the gearbox a little, and relieved the rivet heads somewhat with a riffler file which seemed to do the trick.

I've never been troubled with a leaking primary case on this bike, so this trap seems to be working.

I have some new Renold primary chain, and I need 80 pitches. I've cut it to 81 pitches just to make it easier to check - avoiding the rest of the 10' length that I bought. I couldn't get it to fit, so I checked the teeth on the sprockets - 20 on the engine and 44 on the clutch, standard for the W/NG.

I'd loosened the rear chain and moved the gearbox forward as far as it would go, but it still wasn't going to go on with 80 pitches. Eventually I walked away and took the dog for a walk, which always clears the mind. Coming back later, I found the rear wheel spindle was stuck in the frame lug and the chain wasn't as loose as I'd thought - with that free, everything fitted as it should.

When cutting chains, you can use the chain splitter from the bike's toolkit - these military bikes are very well equipped. However, if you are on the workshop, it's much better to grind the staked end of the pin off. Whilst the splitter tool will happily push a pin through, it will also separate the roller from the side plate on the inner link which you will have to fix.

Before you finally fit the chain, make sure the inner primary case joint faces have been scraped free of old gasket. Do it now, or it will end up in the chain. Scrape the outer half too, and clean out the screw holes with drills or taps, whatever you need.

I use Threebond 1215 on these cases. Way over specified, but it is what I have and it's a good colour.

Did you spot this earlier? The chain is out of alignment and the outer case won't fit. I have the clutch sprocket on backwards.

That's better. Fitted and screwed down; clutch next.

This is the later tab washer for the clutch basket screws. Here, I've bent the corner of each tab up a little, which is very difficult to do when they are in situ:

And here is the clutch centre with a new nut and tab washer. I have done these up tight but I will not lock any of the tab washers until I am sure that I have fixed the rubbing problem.

I'll fit the pressure plate, cups, springs and nuts and we can use the kickstart to get some oil pressure.