BSA B34 Gold Star Clubman

 

 

 

 

Make Model

BSA B34 Gold Star Clubman

Year

1954 - 70

Engine

Single, OHV, 4-stroke

Capacity

499 cc / 30.5 cub in.

Bore and Stroke

85 x 88 mm

Compression Ratio

8.75:1

Cooling System

Air cooled

Lubrication

Dry sump

Exhaust

Single, stainless steel and chrome

Carburetor

Single Amal Monobloc

Ignition 

Lucas magdyno, 6V

Starting

Kick start

Clutch

Wet, Multi-plate

Maximum Power

31 kW / 22 hp @ 7000 rpm

Transmission 

4-Speed manual

Final Drive

Chain

Wheelbase

1400 mm / 56 in.

Seat Height

770 mm / 30.5 in.

Front Wheel

WM3 x 19 in.

Rear Wheel

WM3 x 19 in.

Front Tyre

3.00 x 19 in.

Rear Tyre

3.50 x 19 in.

Front Suspension

Telescopic fork

Rear Suspension

Swinging arm with twin shock absorbers and dampers

Front Brake

8 in., drum

Rear Brake

7 in., drum

Dry Weight

171 kg / 384 lbs

Fuel Capacity

18 L / 4.8 US gal

Top Speed

177 km/h / 110 mph

Colours

Black/chrome

Source

Wikipedia, Bonhams

 

 

The BSA Gold Star was made from 1938–1963. They were 350 cc and 500 cc single-cylinder four-stroke production motorcycles known for being amongst the fastest bikes of the 1950s. Being hand built and with many optional performance modifications available, each motorcycle came from the factory with documented dynamometer test results, allowing the new owner to see the horsepower produced.

In 1937, Wal Handley lapped the Brooklands circuit at over 100 mph (160 km/h) on a BSA Empire Star, and was awarded one of the traditional Gold Star pins for the feat. That inspired BSA to produce the BSA Gold Star. The first Gold Star was an M24 model. It had an alloy 496 cc engine, an Electron alloy gearbox, and a light tube frame devoid of sidecar attachment lugs. This model continued up to the start of World War II.

1948 YB32
After the war, the all alloy 348 cc B32 Gold Star was released, with a very large list of optional components. Once ordered the bike was assembled by hand, and the engine bench tested. They were 20 lb (9.1 kg) lighter than the comparable cast iron barrel and head B series single. They were successful in the 350 class from 1949 to 1956. They could be specified in tourer, trials, ISDT, scrambles, racing or Clubmans trim. The YB is taken from the beginning of the engine number – YB is 1948, ZB is 1949.

1949 ZB34
The 499 cc B34 Gold Star had a modified crankshaft and a different design main bearing. The 350 continued. In 1950 both received larger front brakes. In 1952 the 500 gets a new Bert Hopwood design head, and the 350 had a new head of that design the following year.

1953 BB34 and BB32
In 1953, a swingarm duplex frame was introduced, along with an improved gearbox.

1954 CB34 and CB32
An optional CB engine was given more and squarer finning, a stronger crankshaft, a shorter connecting rod, oval flywheels (500), improved valve gear, and an Amal GP carburettor.

1955 DB34
The DB Gold Star had an improved oil feed to the crankshaft, and finned front brakes. If the buyer specified Clubman cams and timing, he also received a special silencer. At the end of this year the BB and CB models were discontinued.

1956 DBD34
The 500 cc DBD34 was introduced in 1956, with clip-on handlebars, finned alloy engine, polished tank, 36 mm bell-mouth Amal carburettor and swept-back exhaust. The DBD34 had a 110 mph (180 km/h) top speed.[citation needed] The Gold Star dominated the Isle of Man Clubmans TT that year. Later models had a very high first gear, enabling 60 mph (97 km/h) plus before changing up to second. Production ended in 1963.

End of production
Towards the end the Gold Star was only offered in scrambles, or Clubmans trim. In 1963 Lucas ceased to produce the magneto used in the B series, and that line of singles was ended. Alternator models continued to be sold until 1961 as GB33. The demise of the Lucas magneto was a prime reason that BSA and Triumph reconfigured their pre-unit-construction parallel twins into engines with integral gearboxes, simultaneously converting the ignition system from magneto to battery & coil. The Gold Star was not considered for progression to unit-construction, and instead the 250 cc BSA C15 was developed (via the B40) into the 500 cc B50. Although the B50 never attained the kudos of the DBD34, a B50 fielded by Mead & Tomkinson once held the class lap record in the Production TT, as well as gaining results at the 24-hour endurance races the Le Mans Bol d'Or and at the Montjuïc circuit in Barcelona. CCM used BSA B50 bottom ends in their early specials.

On Wednesday 30th June 1937, a specially prepared Empire Star 500 ridden by the great Wal Handley achieved a 100mph lap of the Brooklands circuit on its way to a debut race victory and award of the 'Gold Star' that would give BSA's new super sports model its evocative name. Possibly the most successful production racing motorcycle ever, the post-war Gold Star formed the mainstay of clubman's racing in the 1950s. In fact, it was the model's domination of the Isle of Man Clubman's TT which led to the event being dropped after Gold Star rider Bernard Codd's 1956 Senior/Junior double victory. While its trials and scrambles derivatives demonstrated the design's versatility by chalking up an equally impressive record in off-road competition, for the majority of enthusiasts the 500cc DBD34 in Clubman's trim is the epitome of the 'Goldie'. The DBD, the ultimate road going 500 Gold Star, appeared in 1956 when the famous RRT2 close-ratio gearbox and 190mm front brake became standard equipment. From then on BSA's perennially popular sporting single changed little until its much lamented demise in 1963. Today, the Gold Star remains one of the most highly sought after of post-war British motorcycles and is supported by a most enthusiastic owners' club.