Dear fellow Ariel owners,
This is my first post on the board and in fact it is regarding my first Ariel purchase. I will appreciate any help you can provide. I recently bought an Ariel square four. After buying it I found that it is a non-matching number bike. Here is a picture:
Bike origin: The Classic Motorcycle Warehouse (also called Classic Style) in Seaford, Victoria, Australia. Sold by them to a buyer in Hawaii. Then bought by me.
Frame: is 1948 (XP series)
Engine: is 1937 (DC series)
Gearbox: has a stamp: XLBAPDH 62179
Current condition: not in running condition
First obvious problem faced by us: the kick starter was not able to turn the engine over
My first question was that is this the correct gearbox?
Paul Jameson commented: “I suspect that the gearbox fitted is from an Ariel single. It is certainly pre war from the number you give. The Square four gearboxes have a mainshaft which is longer than the singles one. The gearbox casing is also different as the mounting lugs are offset to line up the chains”. Paul sent us a diagram showing how the mounting lugs are different between singles and SQ gearbox. It appears that we indeed have a singles gearbox fitted to our SQ4.
Then our team went ahead and took the gearbox, clutch, and primary drive apart. We found out that the mainshaft in this bike was built of two pieces (the long rod and a sleeve like ending). Please check the pictures below. The first picture shows the mainshaft with the sleeve fitted to it. The second picture shows the sleeve removed. The mainshaft rod was freely rotating inside the sleeve. That is the reason the kick was not engaging the engine.
Our second question was: is the SQ4 mainshfat built of two pieces?
Paul Jameson answered that question: “Somebody has modified the singles mainshaft for use in the Square Four. The mainshaft should be one piece, without the larger diameter section that the "sleeve" fits over. You need a replacement Square four mainshaft but you can modify the mountings of the gearbox case rather than getting a Square Four case if you want to”.
We then sourced a correct SQ4 mainshaft. Please check the picture below. This mainshaft is exactly 12 inches long.
We put the mainshaft in position. Check the picture below. Now we are facing the problem that the new mainshaft is not long enough on the clutch side for the cluth assembly to fit over it. Interestingly the mainshaft which was origanlly fitted in this bike fits beautifully but then it has the aforementioned problem of being split in two pieces.
Here are our questions:
1) What is the correct length of a mainshaft for this model of SQ4? Is our new mainshaft (12 inches) correct?
2) Picture above has the new correct mainshaft in place. But it is not projecting far enough to fit the clutch assembly over it. How far the mainshaft is supposed to project into the primary side?
3) The old mainshaft with its sleeve fitted is about half inch longer than the new mainshaft. As I mentioned, it fits beautifully in terms of length. Our team is thinking if we can just weld or pin that shaft and sleeve together and reuse it. Any thoughts here?
4) Paul commented that “you can modify the mountings of the gearbox case”. Please see picture below. I am guessing we can shave off the part of the mounting lug which stick out. But I see two problems. First, we will gain only half centimeter maximum which is probably less than the gain we are looking for. And secondly, it will throw the secondary chain out of alignment. Right now the secondary chain is perfectly aligned.
Any thoughts and comments are appreciated.
PS: does anyone have any idea of bike's history? How is ended up in Australia? I emailed classic style and they never cared to reply back.