You raise some valid points Gary, and more.
I was about when brand new unit twins were being sold in the showrooms. While the BSA bikes I saw did conform to a standard the T120 was less so. We had some real mixtures and a few parts bin specials.
What we have been seeing with all of our Y suffix bikes is a remarkable conformity to the model.
They are almost 100% standard bikes, nothing out of the ordinary whatsoever.
I am sure the figure was never 100% across the board, we do know the factory fitted whatever was to hand. The dealer then did whatever was required to sell the bike as well.
The only item that stands out in my memory is some earlier swing arms being seen on the 1969/70 Y bikes. Certainly one bike, maybe two or three max.
Of the three groups of Y bikes they are all what we expect to see for that model, well generally as I say.
What I am concerned about are the 'zero' bikes.
I may have been wrong with Arnstein's Spitfire the other day.
While the A65SA 73430Y number he gave does fit in with our range of 'pre-hybrid' MkIII Spitfires (as 13430) he is adamant the frame stamp is a '7'.
It could be an accident, as you have suggested for this other number. We still have the issue with the 1968 frame parts though, and the condensor bridge. It was not a normal Mk III then.
John owns a 'zero' bike. There are very few of them about.
He either knows, or is suggesting, Arnstein's Spitfire is one of them.
John is saying that the S/N 7343 may have been a MK III.
The engine would have probably been a Dash Y. Unfortunately we don't have that or many details.
For the factory to add the '0' to the frame is easy. We should be able to see a pic even.
The engine would be a little different. The Hyphen and the Y would be stamped over with a zero stamp in some manner.
Ok, what should have happened to this bike.
It is a normal Y bike and with a S/N reasonably early in the season. It would have been expected to be shipped before Xmas 1966.
That is fine but obviously something else happened to this bike.
The number is now different. The frame at least has 1968 features and the engine at least now has the number 73430Y
From the registration papers. The Y must have been there.
The zero must have been added before the end of 1967 for the Norwegian papers to have that detail.
It is not much to work with unfortunately.
We don't know if the bike was ever a Mk III or was made as a Mk IV.
If we look at the despatch books it must fill in some of the blanks.
I could accept this bike being reworked at the factory and despatched in August or so as a 'zero' bike in 1968ish configuration.
John has a bike 11105, and with a zero replacing the hyphen.
There are not many of these bikes about. I am sure John will be hot on the case of tracking them down.
The spreadsheet has a few but again is light on shipping dates etc. I suspect they went early in the 1968 season, again possibly affected by the shipping strike though.I think we have a fourth group of bikes.
Indeed I believe that these were the bikes that were reworked at the factory.
That being the case we should be seeing the shipping (and receipt) details for those few serial numbers.
I am not sure we can assume the Hybrid Spitfires are in the same category.
Arnstein's Spitfire was possibly at a lesser level of rebuild than a complete whole new bike.
His has the original frame, why then was the condensor bridge added ?
Did they put new points in the engine, the later 6CA type ?
We have seen that he still has the original engine though as the number 7343-Y was modified to 73430Y.
I am thinking that these bikes were reworked and possibly had 1968 features incorporated.
Does your bike have any/many John ?
Did the original engine get put into a new frame ?
Do we know of any more ?