Motorbikes were a form of ground transport, typically able to carry one or two riders. It
The Monk's TARDIS briefly took the form of a motorbike when the First Doctor reprogrammed its chameleon circuit, ultimately changing its outer form to that of a police box. (DW: The Daleks' Master Plan)
A number of UNIT troops used motorbikes. (DW: The Ambassadors of Death)
Billy had a motorbike with sidecar called The Vincent. The Seventh Doctor drove it for some time. (DW: Delta and the Bannermen)
In Pervale, the Seventh Doctor faced Midge in a duel which involved the use of motorbikes. (DW: Survival)
Blaid Drwg was a motorbike gang. (TWM: Jetsam)
Sarah Jane Smith used her Sonic lipstick on a motorbike. It sparked and disorientated the rider. (SJA: The Lost Boy)
Rory Williams and Amy Pond pursued their daughter Melody on a motorbike in 1939 Berlin. To do the same, the Teselecta was able to change its shape into a human riding a motorbike. (DW: Let's Kill Hitler)
