DOUGLAS 2 3/4 HP QUESTIONS

[biellestanche]

Good morning, I'm rebuilding some Douglas 2 3/4 HPs that had been dismantled for too long.
I have a few questions for the experts:
- Is it possible to determine in which year the cylinder heads changed from fully radial finned to partially parallel finned?
- The catalog shows two frames that have the same shape in the steering head area but are dated differently: in my opinion, there's an error; the left frame should be from 1917 to 1919.
- In the photographs of the two frames, in the steering head area, there are differences with the curved reinforcing tube, which was later removed; the frame with the reinforcing tube dates back to 1917. Can I assume that the reinforcing frame was used until 1917?
Is there any additional documentation to accurately determine the dating of the various stages?
Thanks everyone for the replies, and sorry for asking so many questions.
Alessandro from Italy

[cardan]

Hi Alessandro,

I'm not an expert on the 2 3/4, but I'll have a crack at answering your questions.

First, it's worth pointing out that there was a very disruptive war 1914-18, so while there were many announcements regarding new models with very specific new features, sometimes the output of the factory did not match exactly the description in the magazines and catalogues.

For example, for 1916 there were big announcements, including:
Larger head bearings (still with triangulated support to top of head)
New carrier for two large tool boxes
Detachable rear stays and fork, with extra-wide rear mudguard
New front fork with U shackles
New brake design, with rear shoe on compensated linkage working inside V of belt rim
New cylinders with removable valve guides
AMAC carburettor with warming jacket...

Yet there were WD Douglases from 1917 that were supplied looking exactly like 1915 models, with none (or very few) of these features.

Add to this the large-scale renovation of WD models, both during the war and after for civilian use, and it's sometimes difficult to put an exact date on a war-time Douglas.

So to your questions:

The cylinders changed a bit over the years (for example the larger fins and removable valve guide for 1916), but the W20 model in the "Peace" catalogue for 1920 still showed cylinders with the radial fins and fin-less inlet ports. Cylinders with lots of parallel fins are a 1920s thing.

The steering heads changed a bit (like the bigger head bearings for 1916) but the tubular brace to the top of the steering head was there right through the war. The steering head without the brace is described in the 1920 catalogue.

The best dating info we have is the frame number, stamped near the gearbox mount. Let us know the frame and engine numbers and we can estimate a date.

Cheers

Leon

[biellestanche]

Thanks, Leon, for your valuable information.
I had thought that the war had also created disruption in the years that followed, particularly among companies that produced large quantities of parts, such as Douglas and Triumph.
If we add that practically 85% of the Douglas 2 3/4 HP parts are interchangeable between the 1914 and 1924 models, we've said it all.
For the dating based on the numbers, I referred to the valuable and detailed table published on the website.
Thank you for your expertise and response.
P.S. Several Douglas motorcycles "resting" in my garage come from Australia. Many arrived disassembled, and I can't know the engine-frame pairings, so to put them together, I've always used the published table.
If they had come from the UK, it would be easier to match the engine and frame by referring to the catalog published on the VMCC, which lists the make, model, date, chassis number, engine number, gearbox number, and UK registration number.
Alessandro

[cardan]

Hi Alessandra,

The Australian connection is interesting. Very surprisingly, we were getting new, civilian Douglases landed well into 1917, well after most other British imports had ceased. These were described as "1917 Models" - I'd guess there weren't "1917 Models" in the UK. Not sure exactly what these looked like.

BSA was probably the only other UK manufacturer to land 1917 models out here.

Cheers

Leon

[EW-Ron]

Claude S Wood at 175 Queen St in 1917 is listed as supplying the Australian made CSW v-twin,
from AG Healing & Co with either a Deluxe or Precision engine and Druid forks.
When you have nothing to sell, make your own.
175 Queen St is in a somewhat valuable commercial district these days.
But we diverge, muchly.

[cardan]

Divergence is good, on occasion. Here's my Healing DeLuxe (the real engine is on the bench); the CSW was identical, other than Healing's 3-speed AGH gearbox and "CSW DeLuxe" on the tank. One CSW has survived, and is currently being restored.

So we don't get into trouble, here's notice of the last wartime shipment of Douglases received by Gard Bros in Adelaide, July 1917.

Leon

[Hutch]

Hi Alessandro, Leon and Ron,

Apologies in advance for a long winded post coming up – I hope I don't add to the confusion 😊. I think Leon is on the money with his reply. I had a look through some Douglas literature and cannot come up with an exact explanation for your frame question, but following is my best guess stab at it - as usual more questions than answers!;

Frame Conundrum – will the real 666D please stand up.

The Handbook of the Douglas Motorcycle 1916 booklet shows a picture of the parts of the newly released "1916 spring fork". There is a short note about the "1916 spring fork"  at the end of the 1919 2 ¾ H.P. Spares List Errata (for the 1916 Handbook, but released in 1919) that states that the "1916 spring fork" was not used on the W.D. Machines.

The 1919 Errata also refers to the "1917 spring fork" and lists the parts with the same "1500" range that the later 1922 parts book use. From 1919 onwards there are only parts listed for the 1917 onwards spring forks and the 1916 version part numbers have disappeared. I have put the pages from the 1916 booklet and the 1922 version for the forks together on the same page and attached it below. Although the 1916 and 1917 onwards version are similar in design they do not appear to be identical, (even considering artistic licence in the pictures as can often be found in Douglas literature).

Note that the part numbers are different. Douglas do not appear to change part numbers on identical parts very often unless that part has been superseded or by error.  So, it appears there is possibly a 1916 spring fork design, followed by a slightly different 1917 spring fork design, of which the 1916 version was not used on W.D. 2 ¾ H.P. machines (as Leon comments, features like the "1916-17 spring fork" do not appear to have been used on the WD models).

The steering column (723D) used for the early one piece forks (i.e. commonly referred to as "Veteran Forks") is 1" in diameter. The later forks use a steering column 1579D which has a larger diameter of 1 1/8". I looked at my 1915 frame (reinforced headstock version of 666D, not the one shown in the 1922 onwards parts booklets) and the later steering column 1579D, will physically not fit (Edit: maybe the headstock could be modified for the stem to go through, but the races for the larger diameter column may still not fit). I have looked through all the parts books I have and cannot find a frame part number other than 666D for the 1915 to 1919 period, so I am unsure what the part number for the "1916 spring fork" frame would have been. If the "1916 spring fork" was to be used in the 1915-1919 W.D. style frame without modification, it would have to have a 1" steering column.

Frame part number 1813D, the non-reinforced headstock for the larger diameter steering column, is dated from 1920 onwards. I cannot find a reference to 1813D earlier than this.

So, assuming the steering column for the "1917 spring forks" was 1 1/8" diameter, then I assume Douglas must have manufactured a different frame to the W.D. machines of 1915-19, or at least changed the headstock - BUT in the 1917 and 1918 Douglas advertising supplement, we have the 1916-17 style spring fork on a (EDIT: modified , see Leon's post below) 666D reinforced headstock frame! (see attached picture). All very confusing.

Does anyone have a picture or details of such an existing bike with these features? Cannot say that I have ever seen one but it would be easily missed I guess ?. I wonder if the "1916-1917" style spring fork only reached production prototype stage in 1919-1920? - I don't know the answer to that.

So why does the picture of frame 666D in the 1922 parts book and onwards, not have the "reinforced" headstock (673D and 673D)? Maybe because it is the "prototype" frame for the "1917 Spring Forks" which was possibly not released to the public until after the war and is not a picture of the "real" 666D frame of 1913-1919 (comparison picture from 1916 parts booklet attached)? Note that the headstock part number 673D shown in the 1922 onwards parts booklet, is incorrect for this headstock and appears twice on the same part – so I guess there was also possibly some confusion for the "artist" who produced the image?

We know that Douglas was prevented from selling to the public in the latter part of WW1 and also for logistical reasons, from drastically altering the design of the 2 ¾ H.P. (I.e. supply of parts) by the war department. I think it was some time in 1918 when they were released from this obligation (?).

So, my guess is that Douglas used the "wrong" picture for the 666D frame in the parts lists from 1922 onwards, and the frame shown is the earlier frame modified by using headstock 1813D so that the "1917 spring fork" design with 1 1/8" steering column can be used with the 666D frame. This modified frame, with an unidentified part number, was possibly used alongside the refurbished ex W.D. machines and the others made up from surplus parts from WW1 until it was superseded by frame 1812D in 1920.....guess only on my part.

Note the headstock on ADD5....(from the Stilltime Collection
https://www.stilltimecollection.co.uk/search/Douglas%20motorcycle?qv=6d9f6aac-6915-4457-b16b-71b5d025bb80).........can we date this picture? (Edit: added picture of Model W from 1918 Advertising Supplement - looks similar in many features to ADD 5....the advertising gumph also notes that a one piece headstock is to be used and sturdier bearings)

Please correct me if I have stuffed anything up and I will endeavour to correct it.

Cheers

Hutch

p.s. I do note the number of the1913 - 1919  frame is "666" !!

[cardan]

Hi Ian,

Steering head and fork aside, one of the main features announced for the "1916" frame was the removable rear stays - both top and bottom - see the pic of ADD5.

I think (?!) that the various wartime designs for rear springing used a similar front part of the frame.

ADD5, and the other pics in your post, show this type of frame, yet I don't think I've ever seen one in the flesh, or in a parts list?

Cheers

Leon

[Hutch]

Hi Ian,

Steering head and fork aside, one of the main features announced for the "1916" frame was the removable rear stays - both top and bottom - see the pic of ADD5.

I think (?!) that the various wartime designs for rear springing used a similar front part of the frame.

ADD5, and the other pics in your post, show this type of frame, yet I don't think I've ever seen one in the flesh, or in a parts list?

Cheers

Leon

Hi Leon,
Well done spotting the detachable upper and lower rear stays!!

I noticed that as well but was trying not to distract from Alessandro's headstock question :-).

As you say, I gather Douglas "played" with some different rear spring frame designs during WW1. I think there are some comments about it in Clew's best twin and there is some info in The Motorcycle publications during the war. I will have a look if I get a chance. I think at least one version went to France for testing (??) and also there were some patents Other than the pictures in the Advertising supplements and the picture of ADD5 I don't have not seen any other pictures of this style of frame for the 2 3/4H.P. Like yourself I have never seen any part numbers for this listed so I assume it never made it to production. There was the 3 1/2 HP spring frame which has been discussed in this forum before. At least a few of these were produced but I cannot remember seeing a picture of a survivor (?). The frame for that appears to have been derived from the 2 3/4HP version.

(ADD 5 obviously doesn't have the rear spring frame swingarm, but is there a hint of reinforcement under the rear of the tank where a springs could of been attached? Unfortunately hard to see in this picture)

Apologies for getting off track in this thread, but I have attached some information on the 3 1/2 HP spring frame of circa 1919. The lower rear swing arm attachment to the frame appears similar to the one shown in the advertising supplements for the 2 3/4HP from 1916 through '18 and also on ADD5??

Cheers

Hutch

[cardan]

Here's one escapee: https://britcycle.com/bikes/forsale/JBot_Douglas_Trio.htm

It's said to be a "1917 model", but I think we might have to add "civilian", because the WD bikes seem to have stuck with the "ordinary" 2 3/4 frame.

My comment above that I don't know what a 1916-17 Douglas sold into Australia looks like stands. Because they were sold into a civilian market, maybe they had bolt-on rear frames.

Leon

[Hutch]

Here's one escapee: https://britcycle.com/bikes/forsale/JBot_Douglas_Trio.htm

It's said to be a "1917 model", but I think we might have to add "civilian", because the WD bikes seem to have stuck with the "ordinary" 2 3/4 frame.

My comment above that I don't know what a 1916-17 Douglas sold into Australia looks like stands. Because they were sold into a civilian market, maybe they had bolt-on rear frames.

Leon

Well spotted Leon!! First one I have seen a modern picture of ! :-)

If you look at the 2014 LDMCC machine register there are very few survivors from the 1915 to 1918 period. You could well be correct that the civilian bikes from 1917 to say 1919 are of the bolt on lower rear stay type with "1917 spring forks". There cannot have been many of them made?

I will have to keep my eye open to see if I can spot others.

Well done Leon!

Edit: Looks like there were less than 20 1917 2 3/4HP and about 11 1918 survivors listed in the 2014 LDMCC Machine register. There could be many more lurking out there of course, but the survival rate is very low given the number of WD machines that were produced for the war effort. Probably the reason we don't see "civilian" 2 3/4hp from this time period?

Cheers

Hutch

[cardan]

So despite the 1916 range (models U,V & W) being announced in the motorcycle press, and in a catalogue (see Doug Frost's booklet), the bikes sold on the civilian market in South Australia during 1916 were WD models, notably with the old-style frame (albeit heavier than the civilian version). However shipments during 1917 included the "proper" civilian bikes like the Model W, presumably with the bolt-on rear frame.

Obviously I don't know numbers, but I'd guess the bolt-on frame was out there, but much rarer than the "usual" frame.

Anyone got a 2 3/4 with a bolt-on rear frame, lower and upper?

Leon

[Hutch]

Good sleuthing Leon,

Here is a picture of the 1917 Model W from the advertising Supplement in Motorcycling 16th January 1917

(EDIT: was looking at this forum for info on 1917 2 3/4 H.P. and Lat's bike appears to be the "WD" version rather than the "civilian" one;
https://www.douglasmotorcycles.net/index.php?topic=6289.msg23282#msg23282 )

- Hutch

[biellestanche]

Buonasera, cari appassionati, ho letto tutti i post e vi ringrazio per le vostre risposte, le analisi approfondite, le scansioni dei manuali e, soprattutto, il vostro tempo.
Di recente, io e un amico stiamo montando una Douglas con telaio del 1917 con una forcella di nuovo modello, e ho notato che il cannotto di sterzo ha un diametro diverso con cuscinetti di sterzo più grandi. Avevo a disposizione altri cannotti di sterzo, ma nessuno con un diametro di 2,5 cm (1") passava attraverso il tubo del telaio. Solo un cannotto, probabilmente modificato con un perno di bloccaggio a croce, aveva un cannotto da 2,5 cm (1"). La filettatura del cannotto era rovinata e l'ho sostituita facilmente.
Mi chiedo: non è possibile che le officine Douglas abbiano fatto la stessa cosa? Non potendo modificare le specifiche delle motociclette per soddisfare i severi requisiti militari, hanno adattato le nuove forcelle ai vecchi telai?
Mi chiedo anche: è possibile che finora nessuno abbia sollevato questa questione?
Ogni giorno, analizzando cataloghi, fotografie e documentazione, scopro cose nuove che mettono alla prova le mie conoscenze. Ma i veri appassionati non si accontentano delle prime risposte e finiscono per avere tante domande, tante risposte, ma ancora innumerevoli dubbi.
Grazie ancora a tutti. Ho iniziato a pubblicare le scansioni dei miei manuali sul gruppo Facebook "Early Motorcycle Literature", dove tutti possono scaricare materiale interessante.
Alessandro

[biellestanche]

Good evening, fellow enthusiasts, I've read all the posts and thank you for your replies, thorough analysis, scans of the manuals, and, most importantly, your time.
Just recently, a friend and I are assembling a 1917-frame Douglas with a new-model fork, and I noticed that the steering stem has a different diameter with larger steering bearings. I had other steering stems available, but none with a 1" diameter would fit through the frame tube. Only one stem, probably modified with a cross-locking pin, had a 1" stem. The thread on the stem was ruined, and I easily replaced it.
I wonder: isn't it possible that the Douglas workshops did the same thing? Since they couldn't change the motorcycles' specifications to meet the strict military requirements, did they adapt the new forks to the old frames?
I also wonder: is it possible that until now no one has raised this issue?
Every day, analyzing catalogs, photographs, and documentation, I discover new things that challenge my knowledge. But true enthusiasts aren't satisfied with the first answers and end up with many questions, many answers, but still countless doubts.
Thanks again to everyone. I've started posting scans of my manuals on the "Early Motorcycle Literature" Facebook group, where everyone can download interesting material.
Alessandro

[cardan]

...Since they couldn't change the motorcycles' specifications to meet the strict military requirements, did they adapt the new forks to the old frames?

Hi Alessandro.

In the discussion above we talk about changes announced in late 1915 for the new 1916 models - this included the larger head bearings, the bolt-on rear frame, linkage brake, the new fork etc.

Everything I've seen suggests that the military models adopted none of these new features, while a small number of 1916-17 civilian models adopted all of them.

I noted that "military" bikes were sold on the civilian market in South Australia during 1916.

It seems likely to me that, from the factory, a bike was either a military model OR a civilian model. I've not seen evidence for "half-and-half" bikes, with new forks on old frames, linkage brakes on military models, or other combinations of features.

Somewhere on the forum there's a thread about refurbishment of ex-military bikes at the end of the war - mostly 1919. At that time anything could have happened, including modifying new forks to fit old frames.

I assume the 1917 frame you are working on is a military version, without the bolt-on rear stays?

Leon 

[cardan]

About renovation of military models: https://www.douglasmotorcycles.net/index.php?topic=9218.0

[biellestanche]

Hi Leon, the 1917 frame currently in the process of being assembled has only the section from the wheel hub to the seat bolted together, while the horizontal section is welded together.
I don't remember if this frame also came from Australia, but I still have an identical frame dating back to 1917 with the same features.
They could be from motorcycles Douglas sold to civilians during the war, but it's impossible to trace this.
They are not numbered in the British VMCC registers.
Thanks Alessandro

[cardan]

Yes, fair to say that the WD-style frame outnumbered the "official civilian-style" frame in 1916-17. I had a trawl through internet images - both period photos and survivors - to confirm. Barely a bolt-on frame to be seen.

Does anyone have one?

I suspect Australia might be the place to look. Drag out those rusty frames...

Leon