TRYING TO IDENTIFY MY GRANDFATHERS MOTORBIKE

[XAVI_MONTORNES]

Hello, my name is Javier Montornes and I would like to know if in this forum I can get the identification of an old motorcycle that had belonged to my grandfather and that he bought about 1925 from an English rider who came to race at the Terramar racetrack located in the town of Sitges, where I am from.
Currently I only have the Spanish license plate but it does not match the traffic description. I would like to know if with some photographs you could tell me the model (I've been told that it's Ángels OK Supreme  by an antique motorbikes professional) and what should I do to get documentation to restore it completely.
It would make me really happy, because the motorcycle has history in our family and I would appreciate so much if someone could help me knowing the model, the year, and if necessary I would also look for spares to restore it.

Thanks so much!


LINKS TO THE PHOTOS:

https://ibb.co/dpgTdhG
https://ibb.co/NpwHV1J
https://ibb.co/r3xSQFm
https://ibb.co/TTnBrC8
https://ibb.co/ckXYHTL
https://ibb.co/sqbBgZY
https://ibb.co/gJXMwSc

[Mark M]

A good photo of the whole machine from both sides would help. However, in one picture I can see what looks like plunger rear suspension. This seems unlikely (but not impossible) on a pre-War machine. Did OK ever actually do this?
REgards, Mark

[R]

Yes a good photo of the whole bike would help muchly.

Its not uncommon for plunger rear suspensions to be grafted on to earlier rigid bikes,
it looks quite possible that this is what has happened here, as other original features suggest.

OK Supreme is a possibility, we will wait for a whole bike photo.
A 'racing' one seems less possible, it looks like a cooking one ?

This 1930 OK has some similar features.
https://en.wikipedia.org/wiki/OK-Supreme#/media/File:Ok_Supreme_500_cc_1930.jpg
Sturmey Archer gearbox can't be later than 1932-ish, so we will wait for that photo.

[cardan]

Hi Javier,

Interesting one! As Mark and R point out, there are a few unusual parts to the bike. The plunger suspension is clearly an update on what looks to be a c1930 bike. There are other modifications as well.

The "flat" Sturmey Archer gearbox would usually be Raleigh, but there's not much Raleigh to the rest of the bike. WHo else used this box?

The "real" (JAP) engine number is on top of the right-side crankcase - see attached photo. If you can tell us this we get the date for the engine. My guess is 1929-30. The one piece Lucas magdyno was last used in 1930.

Cheers

Leon

[cardan]

1929 Coventry Eagle?

[cardan]

The illustration comes from the Motor Cycle, 8 Nov 1928, reporting on the new Coventry Eagles for 1929.

The "new frame" referred to has a cradle tube on each side that extends from the back axle (or bottom of the back plunger in your case) past the gearbox and engine to join the bottom of the front engine plates.

The bump in the (usually very pretty) petrol tank is for the speedo, which is driven from the gearbox. Your bike doesn't have a speedo, so the hole in the tank is blanked off, and the D-shaped bump on the gearbox that houses the speedo drive is not on your gearbox.

48xxx seems like a 1929 Coventry Eagle frame number, but you should check with the British VMCC Cov Eagle marque expert to confirm. The engine number will confirm if the JAP is indeed 1929, and whether it's a 350 or 500.

Coventry Eagle were not a big manufacturer, and had a bit of variety in their models. I think you'll find they offered a 500 ohv just like yours, perhaps a step down from the super sports "Flying 500" or "Flying 350".

Cheers

Leon

[cardan]

Some 1929 Coventry Eagle reading:

https://www.pressreader.com/uk/old-bike-mart/20200801/282179358413617 shows the frame

On this site, start here:

http://classicmotorcycleforum.com/index.php?topic=5777.0

Leon

[XAVI_MONTORNES]

Thank you very much again. I attach photos and also all the numbering !
https://ibb.co/tBDGty4
https://ibb.co/64Ykn58
https://ibb.co/gVsf710
https://ibb.co/pfY1S3B
https://ibb.co/Tk6td9p
https://ibb.co/2n2NvjW
https://ibb.co/VtVdZTc
https://ibb.co/1vCCF3H
https://ibb.co/pvqt0x2
https://ibb.co/Nyx6BNP
https://ibb.co/ydFbjBK
https://ibb.co/4Kff6By
https://ibb.co/c8GXpJf

[XAVI_MONTORNES]

I have not understood very well where I should send the numbering to know exactly model and year   Thank you very much and sorry for the translation

[Rex]

There were/are a quantity of British bikes left in Spain due to the volunteers riding down to join the International Brigade in the Spanish Civil War and never needing them for the return journey..
I was reading about a Cammy Norton which surfaced recently and which will be restored.

[XAVI_MONTORNES]

This particular motorcycle was bought by my grandfather from an Englishman who raced on the terramar racetrack and with the prize he went to vacation for a season.  the year my grandfather bought it, it was not well classified and he had no money to return.  my grandfather was single and he made the wedding trip with my grandmother.  this was before the civil war (1933) since in this year my father was born

[cardan]

Hi Javier,

KOY/S in the JAP engine number translates to:

K = 85.7 x 85mm bore x stroke (500cc)
O = overhead valves
Y = twin exhaust port
S = 1929

The J after the number means "roller-type cam levers and exhaust valve lifter".

The numbers on the face of the drive-side crankcase (50K...) have been added by someone - I think not Coventry Eagle.

So the engine is a typical sporty JAP single of 1929. The very rare racing engines have "R" in the prefix (e.g. KORY).

The gearbox is a 3-speed Sturmey Archer, pretty much a "Type MA" - a modified LS box usually supplied to Raleigh, but also used by Coventry Eagle in their new frame in 1929. The cast number "LS312" is the part number for the shell, and with the stamping WB2 is probably Sturmey Archer code for "LS supplied to Coventry Eagle in 1929". (I have a copy of the list of codes for 1932, but not for 1929.) The stamped number LS4622H is the actual gearbox number, and is pretty good for a type MA around 1928-29. "H" possibly means heavy gears?

The bike looks lovely! It has quite a number of modifications: rear suspension, mufflers, headlamp, carburettor... but I think you could leave them as they are - part of the history of the bike. The tank could be repainted in the 1929 Coventry Eagle colours of red, cream and black.

The Vintage Motor Cycle Club in the UK has a series of "Marque Experts" for the major brands: the Coventry Eagle expert should know all there is to know about your bike. If you email the VMCC with the details of your bikes (engine, gearbox, frame numbers, and a couple of photos) they should be able to forward the info on to the Coventry Eagle Expert who may help.

Cheers

Leon

[R]

The bike looks lovely! It has quite a number of modifications: rear suspension, mufflers, headlamp, carburettor... but I think you could leave them as they are - part of the history of the bike. The tank could be repainted in the 1929 Coventry Eagle colours of red, cream and black.

I agree, if you paint the tank and give the rest of the bike a good polish it would come up very smart indeed.
Keep it exactly as it is, its a lovely example of history on wheels.
That chrome needs oiling or waxing, to help preserve it.

I can't even find of pic of this exact year/model, so they may be quite scarce ?

Good job on the identification too.

[XAVI_MONTORNES]

after all I have made this comparison of motorcycles and I think it is very similar

https://ibb.co/61BX2Qd

[cardan]

Looks great, Javier.

Do you know who did the "modernisation" of the bike? The mudguards look like they come from a late 1930s bike, but the plunger rear end is probably post war. Perhaps it was modernised in the 1950s?

It would be possible to 'fully restore" the bike, but I hope you don't!

Leon