Ariel Owners Motorcycle Club

Paul,

I've now read your article a couple of times and think I understand the various combinations of codes and oils seals etc. The gearbox number on my '39 4G is 2BAPDH59177....there is no X prefix but I can confirm that the main bearing recess is 13/16".

You state in the article that "all pre-war Square Four frame numbers have the prefix letter P.". But my '39 4G is a plunger frame with correct '39 prefix letters of AX. (correct according to Drag frame number list) and club Dating Certificate.

So, I'm not sure what this does to your theory about the X being added to frame numbers after the war....and I seem to have a 4G gearbox that takes an oil seal but without an X prefix on the gearbox number.

Today I had cause to remove the mainshaft from my spare VB/Single BA box...and as the 4G box is still in bits, took a few measurements (all approx!):

Sorry Paul. The reference should be "all pre war Square Four rigid frame numbers have the prefix P". I suspect the the X in your AX frame prefix may mean that an oil seal should be fitted to the gearbox mainshaft but I do not have sufficient data to prove this one way or the other at present. Research may well resume over the winter but I hesitate to publish further articles for fear of boring the AOMCC members to death.

Those are both prewar shafts?

paul.jameson wrote:Sorry Paul. The reference should be "all pre war Square Four rigid frame numbers have the prefix P". I suspect the the X in your AX frame prefix may mean that an oil seal should be fitted to the gearbox mainshaft but I do not have sufficient data to prove this one way or the other at present. Research may well resume over the winter but I hesitate to publish further articles for fear of boring the AOMCC members to death.

Well you're not boring me Paul; I find it very interesting and just wish I wasn't re-inventing the wheel all the time. There is so much useful info out there...on the Drags site, on the AOMCC website, on this forum and mainly in numerous past copies of Cheval...but finding it is the problem.

And yes John, these particular mainshafts are both from pre-war BA Ariel boxes. But I believe this style of mainshaft was used between 1936 and 1947.

The mudguard tin bashing and MIG welding is relentless, but the rear one is slowly getting there....but the front one is a mess. I'm trying to keep them but under those layers of paint, they were not in a good shape and, no doubt, even a gentle bead blasting will show up more work is needed. To ease the boredom, I occasionally dive into another job and earlier in the week the BA box was finished.

But back to the rear mudguard. All the stays were bent and there were multiple drilling in the mudguards; and one stay, the centre vertical one, might be from another bike. Extensive rust damage under the cross bracket at the front of the rear guard...the one that goes between the two seat supports.



The last remaining problem is that I have zero clearance between the gearbox adjusting nut and the mudguard steady to the engine plate:



Looking at my other Ariels from this period, there is at least a 40mm gap here. For the last 5 days, I've been repeatedly examining all brackets, all stays, and the mudguard holes in the minutest of detail in an effort to understand my lack of clearance. Pulling my hair out actually. The guard cannot be out of shape because the sound valances will prevent that, so I cannot alter the curvature of the guard, and nor should I need to. The lifting stay and rear stay for the hinged part are all original and correct, so they restrict how far back you can slide the mudguard.

To cut a long & boring story short, I asked a friend of mine to take a measurement from his original and unrestored '47 4G. He sent me this picture:



So he only has 5mm clearance on his...no idea what will happen if he needed to wind the gearbox back; presumably the threaded rod will come through and eventually touch his guard. His picture was quite a relief and I'm sure I can produce a 5 mm gap on mine (famous last words). A couple more photos before I disappear into the garage for another session

If I can't get to the Parts Book, then not alot is going to happen on the restoration front today.... nice Elephant Hawk Moth larva though.

What a beaut - wot the flip is that doing in your shed, especially at this time of year?!!

SG

Been working on the rear light over the last few days...why couldn't Ariel have stuck with the normal MT110...it would have been so much easier . But they didn't, and for '39 only, we have the motorcycle version of the MT1130 and a centrally mounted lamp. I didn't even bother trying to find an original lamp since they were only used by Ariel and only in 1939, so have done what most '39 owners do and have adapted the car version that was fitted to MG wings etc, the MT1130. The main different is that the car version doesn't have a slot for number plate illumination. Surprisingly, Drags sell the rubber boot that the lamp sits in.







In the photos above, I've already cut the slot in the alloy casing of the lamp and have made a U clamp + bolt & nut to hold it to the plate and rubber boot. The lamp will be painted black.

Took some time on choosing the light source. With modern LEDs, you really do have a huge choice now but eventually settled on a light board rather than an LED based bulb that plugs into conventional bulb socket. This board was the perfect diameter to fit in the alloy lamp case and has two LEDs at right angles for the number plate.









The board comes with a mounting kit for fitting into an MT110, but that was of little use in my application, so I had to make up a brass backing plate that could be secured into the MT1130:





And a quick test of the light. My digital camera hasn't coped too well with the actual LED colour; here it looks orange but in fact, it's a very good deep red. First photo is the lighting circuit, with the 2 number plate LEDs, and a test piece of printed paper. The second photo is the braking circuit which is much brighter, although not in the photos.





Very pleased with the performance of the LED light board and, of course, its very low current drain.. The board works out at approx £25 (incl. postage and VAT), so it is more expensive that a bayonet LED bulb. I had planned on using a red glass stain on the lamp glass, but it really isn't necessary with these red LEDs on the board.

I've got one of those light boards in my W/NG. It's been excellent so far.