Bicycle

Bicycles, also known as bikes, were a common means of transport for humans on Earth from the 20th century onwards.

Uses of bicycles
The Second Doctor used a tandem bicycle along with a pedal-driven helicopter rotor to invent the pedal-copter. (COMIC: Attack of the Daleks)

Whizz Kid used a BMX bike to make his way to the Psychic Circus on Segonax. (TV: The Greatest Show in the Galaxy)

Rudy Zoom claimed he was "the first man to cycle the rings of Saturn". (COMIC: The Eye of Torment)

20th century
In 1913, Martha Jones and Jenny both rode bicycles. (TV: Human Nature)

On 8 December 1926, the Reverend Arnold Golightly arrived at Eddison Manor on a bicycle. (TV: The Unicorn and the Wasp)

On 25 December 1938, Madge Arwell was cycling past a field when the Eleventh Doctor fell from a sub-orbital spaceship. (TV: The Doctor, the Widow and the Wardrobe)

In 1964, Forester drove a big American car, which caused PC Bert Rowse to swerve his bicycle straight into a muddy ditch. (PROSE: Planet of Giants)

In the 1970s, Pigbin Josh, a homeless tramp, used a worn down bicycle to travel around. He accidentally rode over a thin patch of ice and crashed through. He recovered and found an Axos ship that had landed on Earth. The Axos captured and probed him, draining out his life. (TV: The Claws of Axos)

PC Groom used a bicycle to get around Devil's End. (TV: The Dæmons)

The Fifth Doctor was flung into a duck pond in Stockbridge when Jane Potter ran into him on her bicycle on her way to school. (AUDIO: The Eternal Summer)

In 1976, Peter Hutchings met his future wife Emily West in Greenwich Park when he accidentally ran into her, distracted by Ace's jacket. (PROSE: Timewyrm: Revelation)

In 1978, Professor Rumford came to the Doctor's aid while cycling at night. (TV: The Stones of Blood)

In 1981, Adric used a murdered policeman's bicycle to create a distraction to allow the Fourth Doctor to escape arrest. (TV: Logopolis)Supergirl once rode a cyan bike in front of the Moon at night during the opening of an episode of her show, Meet That Hero!, on which she talked about E.T. and the similarities between their histories. When she got off of the bike, it crashed to the ground behind her in the forest she was recording the show in. (WC: Supergirl Meets E.T.)

Although Turlough lived in England for some time during the 1980s, he did not know how to ride a bicycle. (AUDIO: Equilibrium)

The Ninth Doctor visited Earth in 1998 to get Rose Tyler a red bicycle for Christmas when she was twelve. (PROSE: The Red Bicycle, TV: The Doctor Dances)

21st century
A blond man decided to travel to work by bicycle after an encounter with the Tenth Doctor and a time assassin on his bus route. (COMIC: Bus Stop!)

The tyre of Louie Rollins' bicycle was punctured on his way home from school the day after a Hallowe'en party. (PROSE: The Night After Hallowe'en)

The Tenth Doctor suggested that Bowie Base One should have taken bikes with them for ease of transport. Although at first reluctant, Adelaide Brooke agreed with him while running from the Flood. (TV: The Waters of Mars)

Graham and Grace tried to teach Ryan Sinclair to ride a bike, but due to his dyspraxia he couldn't. (TV: The Woman Who Fell to Earth)

26th century
In 2589, Headhunter fell off of a bicycle on Phobos. (AUDIO: Phobos)

In 2595, Bernice Summerfield lent her bicycle to the artist Menlove Stokes, on condition that he wouldn't use it for art. (PROSE: Dry Pilgrimage)

33rd century
Bicycles were used on Starship UK. (TV: The Beast Below)

Uses of bicycle components
The helmic regulator in the Tenth Doctor's TARDIS appeared in the form of a bicycle pump. (TV: Smith and Jones)

Other references
Iris Wildthyme had a tattoo of a bumblebee riding a bicycle. (AUDIO: Iris Rides Out)

Alan Turing was unsteady on a bicycle. (PROSE: The Turing Test)

Zoe Heriot wanted to buy a bicycle at the Frenko Bazaar in order to ride it inside the TARDIS. (COMIC: Bazaar Adventures)

When the First Doctor was interrogated by Lobos on how he came to the Space Museum, he was hooked up to a machine that could read his thoughts. The Doctor simply conjured an image of a penny-farthing bicycle, causing Lobos to order the Time Lord taken to the Preparation Room. (TV: The Space Museum)

References in invalid sources
4 bicycles alternating between red and baby blue in colour were present in a street in New York City behind Gandalf. (NOTVALID: Endless Awesome)