Author Topic: 1932 TT Douglas  (Read 3501 times)

0 Members and 1 Guest are viewing this topic.

Offline cardan

  • Master Member
  • ****
  • Join Date: Jul 2007
  • Posts: 772
  • Location: Adelaide, South Australia
    • Leon's Vintage Motorcycle Page
1932 TT Douglas
« on: 09 Aug 2014 at 11:40 »

Searching for 1932 TT Rudge info, I came across this rather nice illustration of the 1932 TT Douglas motor, from the Motor Cycle of June 23, 1932.

The drawing shows the neat arrangement of the twin carburettors, close coupled to the cylinder heads but still drawing air from a central airbox, in the time-honoured manner dating back to, at least, the 1923 TT bikes (RAs). In fact the main mechanic features of the motor are not too dissimilar to the RA and its progeny - the TT and DT.

Leon

Offline cardan

  • Master Member
  • ****
  • Join Date: Jul 2007
  • Posts: 772
  • Location: Adelaide, South Australia
    • Leon's Vintage Motorcycle Page
Re: 1932 TT Douglas
« Reply #1 on: 10 Aug 2014 at 11:48 »

And here's the beast itself. Note the Webb fork and non-cross-over gearbox.

Prior to the race the chances of the Douglas team were summarised thus: "The Douglases are not quite ripe, and their jockeys are not 80 m.p.h. men." These observations were confirmed in the race itself. Cammy Nortons finished 1, 2 and 3 in 1932 Senior T.T., with the Rudges best of the rest.

Leon

Offline oil baron

  • Full Member
  • **
  • Join Date: May 2011
  • Posts: 66
  • Location: Motueka, New Zealand
Re: 1932 TT Douglas
« Reply #2 on: 10 Aug 2014 at 22:53 »
Hi There Leon

Just a few thoughts on the machine,  I wonder what brakes were used as they do not appear to be Douglas, so were they using Enfield or similar proprietary hubs.  The machine does not have a flywheel clutch, and being a non crossover box, I suspect is it using a Sturmey Archer box set up as was fitted to the very similar looking Dr Joe Bailey/Len Cole and later Colin Clifford 750 cc sidecar outfit.  Though that machine seems to use a modified small air box and conventional carb set up rather than that shown in the first picture, the crankcase and sump appears the same. It also appears to use standard 8" Douglas brakes, with the front brake on the left-hand side. otherwise the machine is looks very similar to the one shown in your post, apparently a total of 3 machines were built.

Thanks for the interesting posts Leon

Regards  SteveL
Steve L

Offline oil baron

  • Full Member
  • **
  • Join Date: May 2011
  • Posts: 66
  • Location: Motueka, New Zealand
Re: 1932 TT Douglas
« Reply #3 on: 10 Aug 2014 at 23:03 »
Hi Leon

Found a better photo of the Dr Joe Bailey/Len Cole/Colin Clifford machine, It uses the same air box as your first photo, but with a conventional carb set up, interestingly the boss at the bottom left-hand side is for mounting the gear change lever.  See the photos on Bonhams Website

http://www.bonhams.com/auctions/19766/lot/322/

Regards  SteveL

Steve L

Offline Doug

  • Global Moderator
  • ****
  • Join Date: Mar 2004
  • Posts: 3186
  • Location: Pennsylvania, USA
Re: 1932 TT Douglas
« Reply #4 on: 11 Aug 2014 at 00:45 »
The 1931-32 Douglas works machines allegedly used Douglas brakes, but they were 9". However I have not seen inside one to see if they used the Douglas band brake. The gearbox was a Sturmey-Archer unit explicitly made for Douglas. Initially with an external posi-stop gear change as see in the Bonham auction advert and then in mid 1933 or '34 with an integral posi-stop like used on Norton 'dollshead' 'box and the Norton retrofits in Douglases favored by the vintage sprinters. Examples of these Douglas-Sturmey-Archer gearboxes survive, but were only used on the Works machines and are very rare. Hence folk modifying Norton 'boxes.

The machine in the Bonhams auction is not Joe Bailey's machine (which was a 1926-28 TT model). It is one of the Works sidecar machines. It was assembled and sold at a Bonhams auction a few years back by Collin Clifford. Then in 2012 it was in the sale again. Bailey's machine initially went to his son, who then after a few years sold privately to a Douglas enthusiast.

I know of about three of the 1930-32 Works bikes. The outfit, a solo, and a Works frame built into a sprinter. There was a fourth, the Bury Brothers outfit, but that burned up in the National Motorcycle Museum fire and disappeared. I think I read somewhere that in 1933 they just used the '32 machines and in 1934 the factory had no official involvement, but they did lend the same machines (which at some point received updated gearboxes) to private entries. The engines were described as sounding a bit "flat" by the journalists (I forget which year this was quoted, but I don't think it matters in the results!), and the entries did not gain any merit.

They used a wider angle between the valves than the earlier DT/TT. From what I can tell (an this is still a bit of a learning curve) the 1930 machines had horizontal ports. In 1931 the exhaust ports pointed downward. In 1932 the inlets also pointed downward (or up if going with the flow.) The inclined inlets can be seen in the engine photo Leon posted.

-Doug


[fix typo. 11Aug14  -Doug]
« Last Edit: 11 Aug 2014 at 12:11 by Doug »

Offline cardan

  • Master Member
  • ****
  • Join Date: Jul 2007
  • Posts: 772
  • Location: Adelaide, South Australia
    • Leon's Vintage Motorcycle Page
Re: 1932 TT Douglas
« Reply #5 on: 11 Aug 2014 at 11:36 »
Here's the description of the 1932 TT Douglas from The Motor Cycle in May 1932:

"LAST week the first of the T.T. Douglases was to be seen down at Brooklands. C. T. Atkins, the well-known Douglas exponent, who is largely responsible for the "upbringing " of this model, was putting it through its paces over the half-mile for the first time.

"ALTHOUGH, at first glance, the Douglas resembles the standard 494 c.c. production model, in actual fact it is entirely different. The cooling area of the barrels and cylinder heads has been considerably increased, even down to the extent of finning the rocker standards, which are cast en bloc with the heads. The 14 mm sparking plugs are centrally disposed between the rocker standards, while the inlet ports lead up from the two carburetters at an angle of 20 degrees to the horizontal. The well-known Douglas air-balancing chamber is, of course, incorporated.

"DRY-SUMP lubrication is employed, a large finned aluminium sump being bolted to the bottom of the crank case. A departure from the normal Douglas practice is the fitting of a Sturmey Archer four-speed gear box, the pedal for the positive foot gear change being neatly mounted at the bottom of the air-balancing chamber. With this gear box the final chain transmission is on the near side, where a large chain sprocket is mounted on the drum of an extremely powerful 9in. brake, heavily ribbed, and well protected from wet.

"THE whole engine unit is mounted in a particularly rigid duplex-cradle frame, fitted with a steering head much larger and longer than has hitherto been favoured by the Douglas people. Special Druid forks are used in conjunction with a heavy type and business-like Enfield front brake and hub assembly. The brakes are interconnected and operated by a near-side pedal. Finally, a large, sloping two-section built-up tank, holding four gallons of fuel, is mounted on the lower tank rail.

"A MEMBER of The Motor Cycle staff who was allowed a short trial trip found that the machine possessed immense power and terrific acceleration from low speeds. The gear ratios were very close together, and it was most difficult to appreciate the difference between top and third gears. But the outstanding feature was undoubtedly the steering over a bumpy road. The machine was rock-steady, and gave the impression that it was absolutely light in weight, so easily did it handle. The brakes were superb, being both light and extremely powerful in operation."

A couple of comments. Re the front fork, it looks much more Webb than Druid to me. Until about 1930 Druid were still using twin side springs on some of their forks, but the "go faster" model was the ES (enclosed spring) that looked a bit like the Webb but had an enclosed central spring. Of course the fork could have been changed between testing at Brooklands and racing in the IOM a month later. Re the cooling fins: those cylinder look like OB items to me (OK, the fin shape is OB), and at least some TT heads from about 1926-7 on had finned rocker standards.

Leon

Offline oil baron

  • Full Member
  • **
  • Join Date: May 2011
  • Posts: 66
  • Location: Motueka, New Zealand
Re: 1932 TT Douglas
« Reply #6 on: 11 Aug 2014 at 20:59 »
Hi Leon

I suspect that in the photo you published it also had an Enfield rear hub as well, if you compare the position of the rear brake actuating lever with the photo of the 750cc outfit which uses the 9'' Douglas brake.  On that machine the brake actuating lever operates through the brake anchor point in normal Douglas fashion, whereas the TT machine has a separate actuating arm, and the brake diameter certainly looks smaller than 9",  Interesting!
Keep up the good work

SteveL

Steve L

Offline cardan

  • Master Member
  • ****
  • Join Date: Jul 2007
  • Posts: 772
  • Location: Adelaide, South Australia
    • Leon's Vintage Motorcycle Page
Re: 1932 TT Douglas
« Reply #7 on: 11 Aug 2014 at 23:32 »

Hi Steve,

Yes the rear brake on the 1932 TT bike doesn't look like the Douglas "TT" item (9" brake drum with bolt-on sprocket, usually on the off side of the machine), so given the parlous state of Douglas in the early 1930s it is likely to be a bought-in item. Since the fornt brake is named as Enfield in the Motor Cycle article, the rear could well be Enfield as well.

The restored sidecar works racer is an interesting machine, but keep in mind it is "restored". If you read the Bonham's description carefully, it doesn't promise exact originality anywhere, so there is some scope for fitting parts that are in keeping with a racing Douglas of the period. The problem of reproduction racers has been a huge problem with sorting out the (genuine) 1932 Works Rudge. I've given up looking at photos of restored machines, because most seem to be relatively modern recreations.

Cheers

Leon

 

motorcycle