Not the same set up as the ST as each low and high beam is separated from each other by the width of the truck but still curious how the regulations are written.
As you said, can't really comapre a 4 lamp headlamp to a 2 lamp headlamp or a single lamp headlamp, or car vs bike.
S7.9Motorcycles. Each motorcycle shall be equipped with a headlighting system designed to conform to the following requirements.
S7.9.1 A motorcycle manufactured before September 1, 2000, may be equipped with—
(a) A headlighting system designed to conform to SAE Standard J584 Motorcycle Headlamps April 1964, or to SAE Standard J584 April 1964 with the photometric specifications of Figure 32 and the upper beam aimability specifications of paragraph S7.9.3; or
(b) One half of any headlighting system specified in S7.1 through S7.6 which provides both a full upper beam and full lower beam. Where more than one lamp must be used, the lamps shall be mounted vertically, with the lower beam as high as practicable.
S7.9.2A motorcycle manufactured on or after September 1, 2000, shall be equipped with—
(a) A headlighting system designed to conform to SAE Standard J584 Motorcycle Headlamps April 1964 with the photometric specifications of Figure 32 and the upper beam aimability specifications of paragraph S7.9.3; or
(b) A headlighting system that conforms to S7.9.1(b).
S7.9.3The upper beam of a multiple beam headlamp designed to conform to the photometric requirements of Figure 32 shall be aimed photoelectrically during the photometric test in the manner prescribed in SAE Standard J584 OCT93 Motorcycle Headlamps.
S7.9.6.2(a) If the system consists of a single headlamp, it shall be mounted on the vertical centerline of the motorcycle. If the headlamp contains more than one light source, each light source shall be mounted on the vertical centerline with the upper beam no higher than the lower beam, or horizontally disposed about the vertical centerline and mounted at the same height. If the light sources are horizontally disposed about the vertical centerline, the distance between the closest edges of the effective projected luminous lens area in front of the light sources shall not be greater than 200 mm (8 in.).
(b) If the system consists of two headlamps, each of which provides both an upper and lower beam, the headlamps shall be mounted either at the same height and symmetrically disposed about the vertical centerline or mounted on the vertical centerline. If the headlamps are horizontally disposed about the vertical centerline, the distance between the closest edges of their effective projected luminous lens areas shall not be greater than 200 mm (8 in.).
S7.3.2Type A headlighting system. A Type A headlighting system consists of two Type 1A1 and two Type 2A1 headlamps
A Type C headlighting system consists of two Type 1C1 and two Type 2C1 headlamps and associated hardware
The maximum wattage at 12.8 volts (design voltage): Single filament headlamp, 55 watts on the upper beam; dual filament headlamp, 43 watts on the upper beam and 65 watts on the lower beam.
Type B headlighting system consists of two Type 2B1 headlamps and associated hardware
The maximum wattage at 12.8 volts (design voltage): 70 watts on the upper beam and 60 watts on the lower beam.
A Type D headlighting system consists of two Type 2D1 headlamps and associated hardware
The maximum wattage at 12.8 volts (design voltage): 65 watts on upper beam, and 55 watts on lower beam.
A Type E headlighting system consists of two Type 2E1 headlamps and associated hardware,
The maximum wattage at 12.8 volts (design voltage): 70 watts on upper beam, and 60 watts on lower beam
A Type F headlighting system consists of two Type UF and two Type LF headlamps and associated hardware
The maximum wattage at 12.8 volts (design voltage): 70 watts on the upper beam and 60 watts on the lower beam.
A Type G headlamp system consists of two Type 1G1 headlamps and two Type 2G1 headlamps
The maximum wattage at 12.8 volts (design voltage) for the 1G1 and 2G1 upper beam is 55 watts and 43 watts respectively; for the 2G1 lower beam, 65 watts
A Type H headlamp system consisting of two Type 2H1 headlamps and associated hardware
The maximum wattage at 12.8 volts (design voltage): 70 watts on the upper beam and 60 watts on the lower beam