Collection: Bulbs S2

The S2 bulb: the single-beam scooter bulb

The S2 is a screw-base bulb specific to the motorcycle and scooter world. Unlike the BA20D dual-beam which combines low and high beams, the S2 is single-beam — a single light intensity, with no distinction between dipped beam and main beam.

This technical simplicity corresponds to the uses of:

• 50cc scooters and learning mopeds (AM category)
• Small urban motorcycles with a single beam
• Old mopeds (Solex, Peugeot 103, Motobécane AV88)
• Certain entry-level 125cc scooters

S2 vs BA20D: what's the difference?

• S2 — screw base, single-beam bulb (1 filament). No separate high beam.
• BA20D — bayonet base, dual-beam 35/35W bulb (low + high beams). Allows switching between two intensities.

These two bulbs are not interchangeable — the base is completely different. Check the reference on the original bulb before purchasing.

Voltage: 12V or 6V?

The S2 is available in 12V (most modern scooters and motorcycles) and 6V (old mopeds, Solex mopeds, Motobécane before 1985). It is essential to check your vehicle's voltage before ordering:

• A 6V on 12V will burn out instantly
• A 12V on 6V will barely light up

The voltage is indicated on the battery or the manufacturer's plate. See also our dedicated 6V motorcycle range.