| SIMPLEX (Amsterdam) | MOTOCICLETA | PAISES BAJOS | AMSTERDAM - NOORD-HOLLAND | 1886 - 1902 |
| SIMPLEX (AUS) | MOTOCICLETA | AUSTRALIA | - | 1930 |
| SIMPLEX (Berlin) | MOTOR | ALEMANIA (REP. WEIMAR) | KREUZBERG-BERLIN - BERLIN | 1921 |
| SIMPLEX (Birmingham) | MOTOR AUXILIAR | REINO UNIDO | BIRMINGHAM - WARWICKSHIRE | 1919 |
| SIMPLEX (Louisiana) | MOTOCICLETA | USA | - LOUISIANA | 1906 |
| SIMPLEX (Mulhouse) | MOTOCICLETA | FRANCIA | MULHOUSE - HAUT-RHIN | 1904 |
| SIMPLEX (New Orleans) | MOTOCICLETA | USA | NEW ORLEANS - LOUISIANA | 1935 |
| SIMPLEX (Torino) | MOTOCICLETA | ITALIA | TORINO - TORINO | 1921 |
| SIMPLIST | MOTOR | REINO UNIDO | GRIMSBY - LINCOLNSHIRE | 1953 |
| SIMSON | MOTOCICLETA | ALEMANIA IMPERIAL | SHUL - THÜRINGEN | 1856 |
| SINCLAIR | TRICICLO | REINO UNIDO | CAMBERLEY-SURREY HEAT - SURREY | 1985 |
| SINGER (Coventry) | MOTOCICLETA | REINO UNIDO | COVENTRY - WARWICKSHIRE | 1876-1901 |
| SINGER (Saint-Étienne) | CICLOMOTOR | FRANCIA | SAINT-ÉTIENNE - LOIRE | 1902 |
| SIPHAX | MOTOCICLETA | FRANCIA | PARIS - SEINE | 1951 |
| SIRDAR (Melbourne) | MOTOCICLETA | AUSTRALIA | MELBOURNE - VICTORIA | 1914 |
| SIRDAR (Westbury) | MOTOCICLETA | AUSTRALIA | WESTBURY-LAUNCESTON - TASMANIA | 1915 |
| SIRIO | MOTOR AUXILIAR | ITALIA | - | 1945 |
| SIROCCO | MOTOCICLETA | CHECOSLOVAQUIA | ŠUMPERK - OLOMOUCKÝ KRAJ | 1925 |
| SIRRAH | MOTOCICLETA | REINO UNIDO | BIRMINGHAM - WARWICKSHIRE | 1921 |
| SIRTORI | MOTOCICLETA | ITALIA | MILANO - MILANO | 1900 |