Pre unit b series identification

PRE-UNIT B SERIES (ROAD MODELS)	348cc, 71mm x 88mm OHV B31 499cc, 85mm x 88mm OHV B33

1945	B31 introduced, telescopic front forks, rigid frame, speedometer in petrol tank, saddle, 3 gallon tank, magdyno lighting.

1947	B33 introduced, as B31 but with larger engine.

1948	Speedometer mounted on front fork, breather moved to timing cover.

1949	Plunger suspension option, revised gearbox, larger dynamo.

1950	Alloy engine introduced and discontinued.

1952	Dual seat option.

1953	Headlamp cowl includes speedometer, ammeter and switch, under-slung pilot light, boxed in rear number plate incorporating stop/tail light and reflector, chrome wheel rims and finned collar on exhaust pipe, new rounder petrol tank. B33 only redesigned engine including modified cylinder with extra fining, 8" front brake and valanced mudguards.

1954	New plastic tank badge, swinging arm rear suspension with alloy chaincase and dualseat as standard. Rigid and plunger frames continued.

September 1954	Pilot light in reflector, steering head lock, ignition changed to pull to retard. Swinging arm frame models monobloc carburettor.

1955	Plunger models discontinued.

November 1955	Hydraulically damped adjustable swinging arm suspension as standard, light alloy full width hubs, valanced front mudguard.

1958	Lucas AC generator and coil ignition, fitted sidecar lugs, 7" cast iron full width hubs, 8" front hub B33, , improved clutch, improved silencer, heavier rear chain, new headlamp cowl incorporating electric horn, domed toolbox lid and oil tank, roll on feet for centre stand.

September 1959	FB31.4352 Frame B31 discontinued.

July 1960	GB33.1541 Engine GB33.654 Frame B33 discontinued

B32 COMPETITION MODELS	348cc, 71 x 88mm OHV

1947	XB32.101 Engine XB31.101 Frame B32 Competition introduced, as B31 different gears, more ground clearance, lighter weight, different tyre size

1949	ZB32.101 Engine ZB31.101 B32 Competition spring frame option. ZB32.GS.101 Engine ZB32S.101 B32 Gold Star introduced, engine has alloy barrel and cylinder head, Amal carburretor, 4speed, hydraulically damped telescopic front forks and plunger rear suspension, 7” brakes, quickly detachable wheels, 3 gallon tank battery lighting, option Lucas Magdyno.

1950	ZB32.GS.2001 Engine ZB32S.2001 Frame B32 Gold Star, 8” front brake with wider shoes.

1953	BB32.101 Engine BB31.101 Frame B32 Competition, Alloy cylinder head and barrel, chromium wheel rims and mudguards, chaincase, chain guard, finned collar on barrel. BB32.GS.101 Engine BB32S 101 Frame B32 Gold Star, modifications as B32 Competition, except cylinder head and barrel.

1954	BB32A.201 Engine BB32R.121 Frame B32 Competition, alloy cylinder barrel and head, welded frame, alloy petrol tank. Swinging arm suspension optional extra. BB32.GS.1001 Engine CB32.101 Frame B32 Gold Star, swinging arm frame standard.

September 1954	BB32A.251 Engine BB32R.201 Frame B32 Competition, pilot light in the reflector, rigid frame standard. BB32.GS.2001 Engine CB32.1501 B32 Gold Star, pilot light in reflector. CB32.GS.501 Engine CB32.1501 B32 Gold Star, Clubmans and Road Racing models, as previous B32 Gold Star but higher compression engine and different gears. No lighting on road racer.

November 1955	BB32A.301 Engine CB34.101 B32 Competition, hydraulically damped adjustable swinging arm rear suspension standard. DB32.GS.501 Engine CB32.4001 Frame B32 Gold Star Clubmans and Road Racing modified engine.

September 1956	DB32.GS.501 Engine CB32.4001 B32 Gold Star Scrambler introduced, high compression engine, 4 speeds close ratio, swinging arm rear suspension and telescopic front forks, 2 gallon tank, dual seat, no lighting.

November 1956	DB32.GS.1150 Engine CB32.6200 Frame B32 Gold Star touring model discontinued.

August 1957	DB32.GS.1279 Engine CB32.6713 Frame B32 Gold Star Road Racer discontinued.

September 1957	DB32.GS.1287 Engine CB32 6712 Frame B32 Gold Star Scrambler discontinued.

October 1957	BB32A.379 Engine CB43.633 Frame B32 Competition discontinued.

September 1958	DB32.GS.1501 Engine CB32.8773 Frame B32 Gold Star Scrambler and Clubman re-introduced.

September 1960	DB32.GS.1741 Engine CB32.10101 Frame B32 Gold Star Scrambler and Clubman continued to special order only.

August 1961	DB32.GS.1793 Engine CB32.11001 Frame B32 Gold Star Scrambler and Clubman discontinued.

B34 COMPETITION MODELS	499cc, 85 X 88mm OHV

1948	YB34.101 Engine YB31.101 Frame B34 Competition introduced. As B33, different gears, more ground clearance, lighter weight, different tyre size

1949	ZB34.101 Engine ZB31.101 Frame plunger type spring frame option, gearbox redesign.

1950	ZB34.GS.2001 Engine ZB32.2001 Frame B34 Gold Star introduced. Engine has alloy barrel and cylinder head, Amal carb, 4 speeds, plunger rear suspension and hydraulically damped telescopic front forks, 8”. front brake. 7” rear, quickly detachable wheels, 3-gal. tank. battery lighting (optional Lucas Magdyno).

1952	ZB34.GS.4001 Engine ZB32S.4001 Frame B34 Gold Star. Die cast alloy cylinder barrel.

1953	BB34.101 Engine BB31.101, BB31S.101 Frame B34 Competition. Alloy cylinder head and barrel, finned collar on exhaust, chromium plated mudguards, chaincase guard, chrome wheel rims, maroon tank. BB34.GS.101 Engine BB32.101, BB32S.101 Frame B34 Gold Star modification as B34 Comp. except cylinder head and barrel, and tank finished in silver with chrome panelling.

1954	BB34A.201 Engine BB32R.121 Frame B34 Competition, all welded rigid frame, alloy tank, swinging arm rear suspension optional. BB34.GS.1001 Engine CB32.101 Frame B34 Gold Star swinging arm rear suspension standard.

September 1954	BB34A.301 Engine BB32R.201 Frame B34 Competition, rigid frame standard. Pilot light in reflector BB34.GS.2001 Engine CB32.1501 Frame B34 Gold Star pilot light in reflector. CB34.GS.501 Engine CB32.1501 Frame B34 Gold Star Clubman and Road Racing models. Pilot light in reflector

November 1955	BB34A.351 Engine CB34.101 Frame B34 Competition. Swinging arm rear suspension standard.

September 1956	B34 Gold Star Scrambler introduced. Similar to B32 Gold Star Scrambler except bigger engine.

November 1956	DB34.GS.1517 Engine CB32.6203 Frame B34 Gold Star (in touring form) discontinued. last engine and frame numbers. BB34A.757 Engine CB34.634 Frame B34 Competition discontinued last engine and frame numbers.

September 1960	DBD34.GS.5684 Engine CB32.10101 Frame B34 Gold Star Scrambler and B34 Gold Star Clubman continued to special order only.

September 1961	DBD34.GS.6504 Engine CB32.11001 Frame B34 Gold Star Scrambler and B34 Gold Star Clubman continued, no longer to special order only.

August 1963	DBD.GS.7162 Engine CB32.11826 Frame B34 Gold Star Scrambler discontinued. DBD.GS.7161 Engine CB32.11826 Frame B34 Gold Star Clubman discontinued.