Reference => Identifying Douglas Motorcycles => Topic started by: KiwiJohn on 08 Apr 2005 at 08:47

Title: My Plus 80
Post by: KiwiJohn on 08 Apr 2005 at 08:47
I just checked through the serial numbers etc of Post War Models and have a minor correction to suggest regarding the numbers series up to the end of 1951

My 80 Plus was manufactured (according to the LDMCC) in August 1951 which is supported by its first registration in New Zealand in December 1951.  

The engine number, and this is confirmed on the registration certificate, as 11408, the table indicates numbers above 11000 were 1952 or later.

Thank you

John Hill
Title: My Plus 80
Post by: Doug on 11 Apr 2005 at 03:26

While I had some good hard data for the low and high serial numbers of some postwar models over their production lifespan, start and end numbers for a given year of Plus manufacture are an approximation (and as you probably noticed rounded off.)  Made all the more difficult in that Plus numbering was mixed in with the regular Mark 4 and 5 series and between the two Plus models.  I do not even try to split up Mark series models by individual year (for example the Mark 5.)

You will note the table states 1951 was the last year of Plus 80 production.  Further up in the text it gives the last Plus 80 as 11967 in November 1951 (I have the 1950 and 1951 dates reversed in that sentence, have to fix that typo.)  So I can raise the serial number range in the table for 1951 to at least 11967, but it could be higher as they might have made a few more Plus 90 models at the end of the year.  

I should probably also clarify where the number ranges are approximate in the tables.  

In a copy of a letter I have from Eric Brockway (former Managing Director of Douglas Sales and Service) he talks of a batch of Plus 80 models just after yours.  "...this was amongst a batch of similar models with engine and frame numbers 11432 to 11444 and 11446 to 11458 and 11460 to 11475."  Then further on- "You will probably notice that there are one or two gaps in the serial numbers I have given and this was because the ones in between passed criteria of a 90 Plus spec and the engine got promptly put into a gold frame and became a 90 Plus."  

90 Plus spec was developing 25hp on the dyno.  Eric also mentioned that machines mentioned above were also dispatched in August 1951, to various UK dealers.  

And some other information points to the fact blocks of the Mark 4 and 5 numbering series were allocated to batches of Plus models.  Yet there gaps in the numbering too, numbers not assigned to any machine.  

Title: My Plus 80
Post by: KiwiJohn on 11 Apr 2005 at 04:09

I am sure there is an interesting tale concerning the early years of my 80 Plus, if only I could find what it is!  According to the LDMCC my bike is not recorded as having been sold,  possible explanations include it having been used for display for some time, maybe sold from the factory or ever stolen!   However the original owner has been traced by me, unfortunately passed away but his widow is still alive,  he raced on the Isle of Mann with a NZ contingent a couple of years (49 to 52 or so)  but never on an Douglas that I can determine.  Considering when my bike was made and when it was first registered for road use in NZ it must have came almost directly from the factory with him on the ship.  This same gentleman set up a motorcycle shop in NZ and that was at a time when there were strong restrictions on importation of just about everything.  

My best guess is that he bought it at the factory and brought it home as 'luggage' and considering that neither his widow or others that knew him can remember a Douglas I can only assume he immediately sold it to the second owner, legal transfer of ownership not occuring for two years as would have been required to avoid problems with the 'luggage' categorisation of the import.

I have found one owner from it's very early days and he assures me the bike, when he had it, was fitted with the woffle box and air cleaner.  Both unusual for a 80 Plus I think?
Title: My Plus 80
Post by: Doug on 11 Apr 2005 at 04:37
...he assures me the bike, when he had it, was fitted with the woffle box and air cleaner. Both unusual for a 80 Plus I think?

Yes, but not as much were it a Plus 90 fitted with air cleaner and woffle box silencer!  All the extras and fittings for the Mark 5 were available for the Plus series, and then some.  As the 80 Plus was supposed to be more 'civilized' than the pukka racing 90, such fitments are not unreasonable.  Even Plus 90s were turned out in full road gear, virtually a golden Mark 5.  Though many, many parts on the Plus, though looking like the Mark series, are just a little bit different.  

Title: My Plus 80
Post by: KiwiJohn on 11 Apr 2005 at 07:50
I am less suprised at the air cleaner than I am at the woffle box as I have the address of the original owner and on the assumption that he personally bought the bike from the factory he may well have selected the air cleaner for his rural location.

Maybe the woffle box was cheaper than two mufflers?