FH - more lift please

 The design of the centre stand fitted to the swinging arm bikes is one of the few weak areas of the last Ariel frame design. It's not very strong - legs are often a little bent, the holes wear oval, the stops deform, and the feet drag along the ground and wear away quickly. It's easy to use but it's faults are not helped by people starting the bike on the stand. 

When restoring a frame it's one of the first things to look at. The stand stops on the frame are likely to be deformed and you want to build them up with weld before you paint the frame. Feet are readily available from Draganfly for you to repair your own stand, and Draganfly have replacement centre stands if you don't fancy doing the welding.

Geometrically then, it's a pretty good design let down by details. The stops aren't big enough, and the single sided foot pressings are just... bad.

Stand repair is something I don't look forward to, or didn't until someone came up with a new method. Personally I've never had much success trying to lever the stand around to get the pins in, and I've hitherto resorted to the old method of pushing pennies, washers or wire into the open coils to get the springs off.

Until this method came along. Setting the scene: the bike is on a scissor lift under the frame rails and the centre stand is in the raised position - I've actually got the front wheel clamped and a cargo strap holding it upright as well.

The first step is to remove the outer circlip and washer from each side - I find it easier to push the pins into the middle.

Next I've secured two cargo straps to the ramp, each one looped around one of the stand feet. If you were doing this without a ramp, you could secure the straps to something heavy in the workshop or perhaps to the rear wheel of the bike.

The next step is to put a bit of tension on the straps - it doesn't take much, just enough to let you feel the pins go loose so you can push them out.

Getting the stand back on is almost as easy. Once you have the straps around the feet and the springs in, you can tension the straps and align the stand eyes with the holes in the frame. You'll have to manoeuvre the eyes to get them to line up, but the cargo straps take the strain and allow you to get the pins inserted without having to hurry.

To repair the stops is easy - if you can weld, or know a man who can. You don't need to add much to the stops - the stand legs are about 8" long and the stops are located 1" away from the centre of the pins, so if you add 1/8" to the stop you can move the leg about 1". Depending on the angle of your stand, that will give you maybe 3/8" of lift.

These eyes appear to be steel castings - they seem to weld very easily.

Wear aside, my stand issues are partly of my own making. When I ordered the shocks, someone suggested that I opt for a bit more length in the shock to give a bit more travel at the rear. Looking back, if I had realised I would need additional lift from the centre stand to accommodate the longer shocks I don't think I would have done it.

FH - centre stand

 I noticed as I was building the Huntmaster up that the rear wheel was in contact with the deck of the lift. Now I did specify rear suspension units that were marginally longer than normal to give me some extra travel and some extra comfort but I hadn't bargained for the fact that the centre stand had so little lift that the wheel touched the ground.

Shame I painted it before I noticed this, but that's the way it goes sometimes. I found a spare moment and removed the springs again using 2.5 mm copper wire wound into the open coils mainly because I didn't have enough thin washers to hold the coils extended. The springs came off relatively easily and I built up the stand stops which were rather worn, using the TIG welder. This picture shows one of the stops part way through the process: I added another layer because this did not prove to be thick enough.

Testing installation for the second time gave me 3/8" of clearance to the rear tyre. The lift has a removable panel under the rear wheel to allow the wheel to drop out and this is something like an 1/8" thick, so we probably have a total of 1/2" or so of lift off the ground. 

That job was a lot easier than I thought it might be. I had the welder set to 60 amps with quite a long stick out to allow me to get into the corners of the stand stops. I didn't have worried about the paint - it was scarcely burnt. 

Whilst I was under there I fitted the spacer between the frame and the primary case. Now all Ariels need this spacer and it is of somewhat variable thickness. Unfortunately I realised that I should have fitted the spacer before the primary case went on; withdrawing the gearbox bottom bolt at this point to fit the spacer would have released the centre stand springs that I had worked so hard to install.

This photograph therefore is here as a reminder to me to fit the spacer properly next time I take the primary case off. Right now the spacer is of a C-section so that it can be fitted without withdrawing the bolt.

FH - centre stand springs

I'd been dreading this job, but needs must. I was forced to face up to it because I needed to get the Square Four on the lift in order to look at the gearbox before the riding season begins, and I didn't want to resort to holding the stand up with an aerolastic.

The way I did this was to take a piece of 2" rolled angle and drill a 6 mm hole at one end; I put a long M6 screw in the hole, and the small eye of the stand spring over the screw. Then I took a bit of 1/2" round bar and used it to stretch the spring by levering it against the end of the vice; I put a 5/16" washer in each of the gaps between the wire coils and when the spring was relaxed it was long enough to push into place by hand. All I had to do then was move the stand to stretch the spring again and all the washers fell out. 

Repeat for the second spring and we are done.

First time outside on it's wheels:

Even my wife says it looks lovely.

FH - Jeff Hunter Engineering

 I've written about the value of the specialist suppliers before, in various media. As you know and can read in this blog I make a lot of (unobtainable) parts myself but we really must keep the specialist suppliers in business, particularly the ones that are making high quality stuff. I was speaking to one only this morning and they are really not making massive profits so we must support them and not dilute their market.

Without people like Acme, Draganfly, the AOMCC and several others, we'd have a lot of unrideable museum pieces.

Here's another example - Jeff Hunter Engineering, a.k.a 'The Rubberman'. I've got all the rubber parts for the FH, the W/NG and the Model A from Jeff. Here's a couple of examples:

Tank rubbers

Centre stand bump stop

FH Dry Build - Centre Stand

First published February 2022

 One of the dry build jobs that I had to deal with was the centre stand. Some years ago - 2014 actually - I had repaired the feet which were completely worn out and recorded the experience here.

I put it back on the bike once the exhausts were in place to have a look. I knew the stand would fit the frame, but it's all the other parts that it has to fit around that are the problem. Here you can see two issues - one, that the stand leg is bent - in fact they are both bent, a common problem and two, that the foot fouls the exhaust: 

With the stand off, you can see that the stops are a bit worn - maybe worth building up, maybe not.

To deal with the bent leg, I have put an old sidestand in the pivot eye, and heated the leg up - it has bent back quite easily.

Next problem - the feet. Do they look uneven?

I've got 30 mm from leg to inside the foot on one side:

And I've got 25 mm on the other! I think that's why it fouls the exhaust.

Maybe I'll have to remove that foot and extend the tube a few millimetres.

September 2022 Update

Months later, coming round to this job at last I turned the bike around in the garage to have a look at the stand foot. The first thing I realised was that the exhaust bracket in front of the engine was not touching the frame; the second was that the silencer was considerably further outboard than the other. The footrest was not fully home on it's spline! I took this picture with the footrest off:

Hey presto, no fouling problem!

QR50 - Assembly

It's a grand time in any project - where you are casting around for jobs and realise there is little left to do on the components. I'm at that place now with the QR50 - the crankcases are closed up, the frame is painted, the forks are done, the shock absorber is done, the centre stand is done and most of the transmission components are ready.

Right now, I can't start the wiring; I can't assemble the generator, the oil pump or the carburetter, I can't look at the exhaust or the generator cover, both of which are significant fabrication activities. What I need to enable these jobs is to put the main elements of the bike together.

Here we go.

First job is to prepare the transmission. The nut shown at 8 o'clock is the fulcrum pin for the rear brake shoes - this is inaccessible when the transmission is assembled:

Here's the fulcrum pin in position:

Next is the output shaft, with a bit of oil to lubricate the oil seal. The bearing is sealed and doesn't need separate lubrication:

And from the other side:

The crankcase is together, and this bracket bolts underneath to carry the centre stand and the rear shock absorber:

We can then fit the main frame spine and sub-frame on top of the crankcases:

The single shock absorber bolts in next:

Here's the other side:

I've fitted the barrel and cylinder head, to get a feeling for the space they occupy:

The inlet tract and reed valves are on place as well. Stepping back:

This is the oil pump drive fitted, which brings us to a close for the moment. The oil pump needs painting and some oil lines adding; I can see the routes and lengths of the harness now and once I have painted the transmission cover and finished the kickstart shaft I can assemble the transmission.

QR50 - Centre Stand

In time honoured fashion, there's a centre stand wear problem. There's always a centre stand wear problem. There's a little fracture in the centre stand as well, but nothing dramatic.

Here's the centre stand bracket with the bike upside down - you see that the bracket also acts as the mount for the bottom of the rear suspension strut:

As usual, the centre stand pivot is very worn; at least the feet are sound. This next picture shows a 10 mm round bar in the offside hole, which is scarcely worn, passing through the nearside hole which is worn to almost 14 mm in places.

Here, I've ground off the burrs and done some preliminary cleaning on the surfaces; I've also marked up the centre of the hole. On the right of the picture, you see a small piece of round bar which has been cleaned up ready to plug the hole, to get it ready for re-drilling.

I opened the hole out with a file, being careful that I rounded the hole in the process. My plan was to minimise clearance around the plug to allow me to use the minimum of filler or to make an autogenous weld.

The next step was to part off a length of my plug to match the thickness of the material. It's supported with a chunk of square bar, since my usual copper heat sink is set up with the FH mudguard.

Here's the completed weld:

Before we get into redrilling the hole, we'll complete the welding work by repairing this small crack in the centre stand itself. It's important to thoroughly clean any repair prior to welding, since we don't want inclusions introducing porosity to the weld. This crack was about 3/8" long, right through the metal and I have made it into a groove with a half-round file:

I welded it up at 45A with MIG wire filler rod:

It cleaned up well with a selection of files:

Yesterday, a good clean up with the wire brush; today, some etch primer:

Here's the centre stand & rear strut bracket mounted on the engine:

Huntmaster Rises up

The start of a build, in my book, is the frame & centre stand. The stand is essential to give the frame a stable start in life.

It was a bit worn:

Not a good picture, i wish I had taken a better one. I added some 16 SWG steel sheet, and a dose of this:

And some of this:

And now I have a couple of these: