It's over 35° C here today, and I don't feel like doing very much so I have been pottering about clearing up the workshop and listening to The Fellowship of the Ring on Audible, read by Andy Serkis.
When all the loose bits were put away I set to to remove the rear wheel rim by undoing all the spokes as I did at the front. Very therapeutic!
The rear brake drum for 1930 features this bolted in ring which is designed to retain any loose spoke heads and prevent them getting involved with the brake shoes - Ariel must have had some mishap to make them realise this would be a problem.
The ring is held in place by three square headed 2 BA bolts which come out easily.
Here is a close up:
The next step is to clean and scrape years of gunge and grease from the brake drum and hub.
The spindle is all present and correct, except that it is very slightly bent. We straighten this out with some heat in the vice.
When it's clean we can put a couple of coats of black gloss on the hub.
The Huntmaster clicked over 400 miles on a run recently and is bedding down nicely. Checking it over in the workshop revealed a front chain that was rather loose, and of course one of the issues that you learn when dealing with these old bikes is that if the front chain is loose the rear chain will probably be tight as sometimes the gearbox will move.
It's time to have a look at both chains, and for this we will use the on board toolkit:
First stop is under the oil tank where we find the gearbox top bolt and the chain adjuster. Loosen the nut on the right a little bit and then use the chain adjuster to draw the gearbox backwards or push it forwards.
Next you need to gain access to the primary case so that you can inspect the tension on the primary chain and later top up the oil. If this is tight use a big flat spanner to undo the inspection cover:
Now you can see the chain. This should have about 3/8" up and down movement and this should be slack movement - the chain should not be stretched tight and you should not be putting much effort into moving it. If the chain is too tight you will be putting undue pressure on the engine main and gearbox bearings, not to mention the chain itself and the clutch basket bearing. Typically the chain will get looser as it wears and you will use the gearbox adjuster to draw the gearbox backwards by a little bit to tighten the chain. When you are done, leave the gearbox adjuster where it is and tighten up the gearbox top bolt.
Turn the engine over on the kickstart and test the chain in a couple of places to ensure it's not over tight anywhere.
Once the front chain is done, we can look at the rear chain. The Huntmaster has a fully enclosed rear chain case and the inspection point is behind a grommet which itself is behind the left hand side silencer. It's easiest to remove the silencer to gain access to the chain:
This is much easier on bikes with only a simple chainguard, but on this one we can enjoy the fact that the rear chain oiler is doing it's thing in keeping the chain clean and lubricated.
Once you can access the chain, slacken off both the wheel nuts and the lock nuts on the chain adjusters shown by the spanner in this next picture. When you tighten the rear chain you must make sure that both adjusters are turned by the same amount - count the flats - to make sure that the rear wheel alignment is maintained. Be really careful with this because setting up the rear wheel alignment is a bit of a pain. Do the lock nuts up when you're done and tighten up the wheel nuts again.
When checking the rear chain it's best to turn the wheel and sit on the bike, because a swinging arm bike will always tighten the chain when the swinging arm deflects upwards. Ariel recommend 5/8" chain movement with the swinging arm deflected to normal riding position and 1 1/4" to 1 1/2" with the bike on the stand. That's quite a difference and comes from the frame geometry - the swinging arm pivot is a long way from the mainshaft centre.
Continuing the investigation and assessment of the Model A, combined with some repairs as we go along, leads us to the rear wheel. Both of the wheels are in a pretty poor state with pitting, missing spokes, and bends of one sort or another. As you will hopefully have noticed I have started posting a lot more YouTube videos on my channel and here is one of them:
As you can see this rim is really for the bin. Around the wheel though there are a few other things that need fixing or replacing; we'll deal with the brake later on in another post and possibly another video but for now there are some small things to be attended to.
First up is a small part which I hadn't really understood very well - the W/NG has one in a mangled state but it's not until I had a proper look at the Model A that I really realised what was meant to happen.
For long period Ariel wheels were fitted with taper roller bearings and these need an adjustment facility built into the design. As you might expect there are two thin nuts to adjust end play in the bearing but of course these require the spindle to be held in place at one end whilst the other end is free and to do this Ariel provided a flat on the right hand side of the spindle. The slots in the frame lugs for the rear wheels are the same on both sides so this flat requires some packing allow it to fit in the same slot. What they do is provide something like a thimble around the spindle to take up the space and to provide a flat, non-threaded surface for the rear wheel chain adjuster to bear on.
This was missing.
To determine the proper material thickness for this thimble or sleeve I tried a few pieces of scrap sheet in the space:
With the sheet selected I cut a strip to more or less the right size and folded it around the spindle:
This prototype is clearly too short!
As an aside, I also wanted to check the thread on the spindle since I had to buy a tap and die set to clean them up. I'm not particularly familiar with CEI threads in this size, so it's best to check with a thread gauge:
This proved it is indeed 9/16" x 20 CEI.
The next step with the spindle sleeve is to roll it up and weld it. Apologies for the terrible picture!
With some work on the linisher, some fine files and a small hammer we have a nice fit over the flats on the spindle:
This is what the finished piece looks like:
The next job is to make a couple of replacement wheel nuts. The kit of parts came with a couple of 9/16" nuts that had been forced onto the spindle. I recut the thread on the spindle just to clean it up but recutting the nuts revealed the fact that they weren't CEI at all - they were very loose. Since they were quite mangled new nuts are the best option.
Starting with the appropriate hexagon material we put a bit in the lathe, centre drill, drill in sequence 6 mm, 10 mm and finish with 13 mm which will do as a tapping size for 9/16" CEI.
We'll put a little radius on the corner of the nut to emulate the factory part.
After drilling, the next job is to cut the thread using a 9/16" by 20 CEI tap. With these big threads, it's easiest to start the tap on the lathe to ensure the thread is cutting concentric with the stock. You don't need to cut the whole thread on the lathe as it's a bit awkward.
What I usually do is take the work out of the lathe and finish the thread on the bench. This gives you a lot more space to operate the tap wrench.
There we go, a nice new wheel nut.
The only problem is that the hex I selected is bigger than stock. Good thing I like lathe work, but I can't find any 0.92" hex stock (other than stainless) anywhere...
These nuts are also a bit thick - for years I have been under the misapprehension that a nut thickness is equivalent to the thread diameter - it's not. BS916 tells us that standard nut heights are more of less equivalent to the thread diameter of the next size down, so these 9/16" nuts should be 1/2" high:
Now to the plan.
We know the rim is corroded and bent - we will probably replace it, and the spokes. We know the sprocket needs replacing and the lathe is too small to do it in the chuck. What we will do is this:
Slacken all the nipples with the wheel still in the bike
Take the wheel out and dismantle it, cleaning the spokes and nipples and storing them
Clean the corrosion off of a patch of the rim, to establish how much thickness has been lost
Attempt to straighten the bend
Decide whether to keep or replace the rim
Obtain a sprocket blank or a BSA A65 or Bantam sprocket ring
Straighten the bent spindle
Build a jig to hold the hub in the lathe for milling
Remove the teeth with a grinder as far as possible
Use the jig to reduce the sprocket diameter with an end mill and create a weld prep, or a step if it turns out to be cast iron...
If the hub turns out to be steel, remove the inner part of the sprocket ring with an end mill, holding it in a large pot chuck on the rotary table
Weld the teeth from the sprocket ring in place, or drill and bolt if it turns out to be cast iron
Rebuild the wheel.
I made this sketch of the setup:
The alternative is to do nothing - fit a new chain and let it wear prematurely, perhaps until Karol of the Slovakia Ariel Klub has his special adapter sprockets available again.
I've started on the rear wheel for no particular reason other than I expect it to be more work and secondly it's easier to get out than the front one for which I need to remove the wheel stop on the bike lift.
The first step is to take a wire brush to the sand cast aluminium surfaces on the inside of the spoke flanges. You don't want to scratch the outer polished faces because it will be the devil of a job to remove the scratches made by a steel wire brush.
For the outside I have used a combination of 180 grit Scotch-Brite pad and a degreaser. This reveals a nice groove which whilst it looks quite uniform has actually been worn in place by the sharp edges of the chain case. When it's clean you can see that the bottom of the groove is quite rough:
With the grease removed we start with the 80 grit stitched mop and polish out as much of the tarnish as we can. We will also polish the edges of the spoke flanges and the ribs around the drum.
This progresses through the 150 and 300 grit wheels to the polishing mops:
It doesn't take long before it's ready for lacing on the rim.
Shame I have ordered the wrong spokes. It's shown here sitting on a 1 1/8" post, clamped in the Workmate, turned to just under 1" to allow the hub to slip over it. We'll lace the wheel in that.
Finally, and it seems to have been a long time coming, it's time to start on the wheels. I've got the tyres now though I have had to compromise with a 90/90-19 front tyre rather than the 325-19 that I wanted, but at least I have everything.
It doesn't take very long to remove the rear wheel from these bikes despite the fact that I have complicated matters by fitting indicators, and these need to come off before the rear of the mudguard can be unbolted.
The first step is to measure the offset using a straight edge across the bearing housing. With that in place we can measure 7/8" to the edge of the rim.
These are quite common wheels so finding someone that could help with the lacing pattern of the spokes wouldn't be difficult. Nevertheless it is good practice to photograph your wheels before dismantling such that the peculiarities of the spoke pattern can be recorded for the rebuild to come. These Ariel full width hub wheels are simple in that the spokes are of two types - those that fit from the outside, and those that fit from the inside; this results in similar lengths but different head angles for the two types. For the half width hubs fitted to all my other Ariels, there are four types of spokes in each wheel.
When you have all the components delivered, and you have recorded your spoke pattern and your offset you can dismantle the wheel. I've done this a few times now and have discovered the quickest and easiest methods to my mind.
Let it be known that we are not going to reuse any of these components other than the hub. Therefore the best way to remove the rim is to cut through all of the spokes on both sides; I use a bolt cutter for this job which makes short work of snipping through each of the spokes.
There we go. The tyre has not even been deflated yet!
Here is the hub with the remains of the spokes. It's sensible to cut the spokes as near to the hub as possible because it is much more difficult to remove the full length of the spoke from the hole in the hub.
You will find most of those little bits of spoke are stuck in their holes through corrosion and dirt. Just wiggle them a bit to release the gunge, and thread them back through their holes.
Removal of the rim and tyre is equally brutal. All I have done here is to take a hacksaw to the tyre, lubricated with some WD40 and sawn through both the tire and part of the rim such that I can cut through both beads and the tyre will just fall off.
And that's it. Apart from a trip to the dump with this scrap metal and rubber the next job is to start polishing the hub.
A few more bits fitted today - the prop stand is on:
…and having received the correct dome head bolts for the front mudguard, the wheel is back in. Obviously this still needs a lot of work, but once the back wheel is on (more work required on the FERC) it will let me move the chassis about and tidy up the workshop.
Some while back, on a very hot Norfolk Summer day, the SQ4 decided that the rear hub had had quite enough of that nasty, sticky grease thank you and vomited it all over the rear tyre and brake.
The trip home was rather gentle, especially as I had to descend from Norfolk's highest spot (!) to sea level, about 90 metres.
Pulling it all apart, there was grease everywhere. The parts washer is a very useful tool:
There are quite a few parts in the QD rear wheel, which is why I am writing this post. Here's an illustration from Draganfly, where we buy all the parts we need:
Putting wheel back together goes like this:
Put in the 4440B-50 grease retainer
Next comes the bearing. I'm using a modern double seal bearing, so we don't have a repeat of this grease leakage problem:
Knock the bearing in
Add the spacer 4346-50
Use a good quality peg spanner designed for the job, and the locking ring will go in easily. I've omitted the original seals, since I am using double sealed bearings.
Eagle eyed readers will notice the 4346-50 spacer is missing...
Locking ring trial fit
Turning the wheel round, we put in the 4471-50 Bearing Spacer Tube, whose smaller end locates in the 4440B-50 Grease Retainer. The Spacer Tube serves to allow the wheel spindle to pass through both sides of the wheel easily. The larger end of the spacer tube locates in another Locking Ring on the other side:
That's the wheel finished. Next, we turn our attention to the brake drum. Clean the bearing recess thoroughly, and include the slot for the circlip. I use Wagamamma chopsticks for jobs like this. Being bamboo, they are strong, flexible and be carved to the shape of the slot. When its all clean, press in the new bearing.
The pictures show the bearing in place, along with the 4440-50 Grease Retainer and the circlip.
Don't be fooled by this picture though, the fixed spindle comes next, with it's circlip.
With the grease retainer in place, you can fit the fixed spindle but you can't get the circlip in...
I noticed a few weeks ago that the SQ4 was trying to drive into the kerb, and required constant correction to keep it on track. There are some roads with steep camber around here which adds to the effect, but on some fast, flat A-roads it still happens, so I need to look at wheel alignment.
To do this, you need to set up a straight edge along the length of the bike to provide a datum for the wheels. Since I don't possess a laser and most of the timber I have is anything but straight, a piece of string is the best solution.
Tie a length of string to a spoke at the front of the front wheel and wrap is around the tire, running the string to the back.
Pull the string tight - you can wrap the string around the back of the rear wheel and tie it off on something convenient. It's very useful to have a bike with a rear stand here, because centre stands get in the way of your string.
You'll note the chopstick under the string at the front. This is there because I have a 3.50 - 19 tyre at the front and a 4.00 - 19 tyre at the rear - so the diameter difference is 0.5" and I have provided a 1/4" spacer (the chopstick) to compensate for this difference.
There is a 1/4" gap at the rear of the front tyre, due to the diameter difference to the rear tyre.
Unfortunately, I also have a gap between the string and the front half of the rear tyre. This is because the rear wheel is not aligned with the front wheel.
You can see this gap here:
Use the tool kit spanners to slacken the wheel spindle:
Use the chain adjusters to move the spindle forwards or backwards. Since my chain tension is correct, I don't want to move the nearside of the rear wheel - I will correct the alignment by pushing the offside forwards.
Now, the front and rear edges of the rear tyre touch the string. I'll check the front wheel has not moved and the string is straight:
Tighten up the wheel spindles and the lock nuts on the chain adjusters and you are done.
