A Brief Synopsis of the Lucas Console Switchgear and Its Evolution

By David Porter, Customer and Technical Support at The Bonneville Shop

During the late 1960s, the BSA Group was busy developing the next generation of Triumph and BSA motorcycles at a leased 17th-century mansion in Warwickshire, known as Umberslade Hall. Situated nearly equidistant from Redditch, Small Heath, and Meriden, the research and development facility was the epicenter for the design teams to update both ranges to the modern specifications needed to compete favorably with the already imposing Japanese machines of the period. Many of the interesting prototypes from Umberslade never saw production, but the most famous of all of them was the new “Oil in Frame” Triumph and BSA 650 models. After production delays doomed the introduction of the new, redesigned Triumph models, they finally landed in dealership showrooms in the spring of 1971. New frames, forks, wheels, airboxes, sheet metal, and countless other updates were present on the new 1971 models, including the introduction of the new Lucas handlebar switch consoles, which also debuted on the BSA B25 and B50 street singles, Triumph T100 models, and the BSA and Triumph triples. Norton Commando models also were fitted with the new switchgear. With the advent of directionals, and an eventual electric starter, the switchgear consoles evolved over the years, as did the motorcycles. The following section chronicles the evolution of the Lucas console switchgear:

“New frames, forks, wheels, airboxes, sheet metal, and countless other updates were present on the new 1971 models, including the introduction of the new Lucas handlebar switch consoles”

• The first generation of Lucas switch consoles used the 169SA body, and first appeared for the 1971 model year. The 39595 high/low/horn switch was generally used as the left switch, while the identical 39596 controlled the directionals and had a “kill” button. These switches were interchangeable, and often were swapped from left to right, and vice versa, depending on the rider’s preferences. Drum brake models from BSA, Triumph, and Norton used the 169SA-bodied switches through the 1972 model year production. The 39595 switch can be identified by the blue wires, whereas the 39596 switch will have green wires, and also include the mysterious white/red wire that is not shown in the wiring diagram and seems to go nowhere. The intent was for an electric starter to be fitted on the machines at some point, so a power lead was fitted to the 54033667 switch-half circuit board, but the lead was not connected to anything in the wiring harness, and the pushbutton for the starter had no function.

“These switches (39595 & 39596) were interchangeable, and often were swapped from left to right, and vice versa, depending on the rider’s preferences.”

• When the front disc brake debuted for the 1973 model year, the 169SA switch body remained, but with a revised handlebar arrangement. The right-hand switch now operated the high/low beam and horn functions, while a brake switch was incorporated into the switchgear on the Triumphs. The switch-half was assigned the part number of 54033751 and was used on the TR7, T140, and T150 models through the 1974 model year. The 39596 switchgear was used on the left-hand side and operated the directionals and the kill button. Norton Commando models used a remote brake switch, so the 39951 right-hand switch gear was essentially the same as the original 39596, but with a longer paddle operating the directionals. The 39949 high/low beam and horn switchgear, as used on the left side on Nortons also used a longer paddle to operate the lighting circuit. While the 169SA switches were used on different motorcycles in differing iterations, they were rebuildable, which was good, as they were not waterproof, and the kill-button contacts are prone to corrosion, causing an electrical troubleshooting nightmare for riders to this day.

“While the 169SA switches were used on different motorcycles in differing iterations, they were rebuildable, which was good, as they were not waterproof, and the kill-button contacts are prone to corrosion, causing an electrical troubleshooting nightmare for riders to this day.”

• The 1975 model year included the new Triumph T160, built at Small Heath, while the Meriden works was in upheaval in the aftermath of the strike. As a result, there was no real production of Triumph twins for the 1975 model year. Lucas, however, was ready to supply the new 181SA switchgear for the T160 models. The new left-hand 30707 switchgear was now a horizontally-split “clamshell” type that provided better resistance to the elements and operated the lighting, directionals, and horn circuits. The improved 30707 was also used on the TR7 and T140 models through the early 1978 models, as was the new 30723, (also referred to as 30708 and 30781) right-hand console, which was a revised version of the earlier 169SA-bodied switchgear, with a prominent long red paddle controlling engine “run” and “off”, and finally a functioning push button for the new electric starter used on the T160 models.

“The improved 30707 was also used on the TR7 and T140 models through the early 1978 models … and finally a functioning push button for the new electric starter used on the T160 models.”

• The electric-start Norton Commando MK3 models featured a new sexy 187SA-bodied black-finished Lucas 35317 right-hand switch gear that incorporated a main/pilot headlight circuit, engine “run” and “stop” toggle switch, and of course, the electric start button. This switchgear was also used on the electric-start Triumph T140ES models from 1981-1982. The left-hand counterpart to the 35317 was the 35316 switch gear, which controlled the high/low beam, horn, and directionals. The 1978.5-1982 Triumph T140D, T140E, and TR7 models also used the 35316 left-hand switchgear, paired with the right-hand 35318 (33709) switchgear on the kickstart-only models.

“The electric-start Norton Commando MK3 models featured a new sexy 187SA-bodied black-finished Lucas 35317 right-hand switch gear.”

“The 1978.5-1982 Triumph T140D, T140E, and TR7 models also used the 35316 left-hand switchgear, paired with the right-hand 35318 (33709) switchgear on the kickstart-only models.”

• With the availability of “new-old-stock” and even good used Lucas switch consoles dwindling, Sparx has been supplying the market with reproduction Lucas-type switch consoles for many years, and we have found them to be of good quality and a relatively inexpensive option for restoring handlebar switch functionality on the 1970s models of BSA, Norton, and Triumph motorcycles. If you have an original Lucas 169SA console switchgear that has survived the past decades, we can supply the rebuild kits for the various iterations.