Jetbike

Jetbikes are freaking sweet rides that any fan of sci-fi will know and imagine owning one day. They fly so no fear of getting a flat tire or getting bogged down need trouble the enthusiastic soon to be dead nujack pilot (what with probably hitting an unseen protruding object below that catches and flips you onto your poor vulnerable skull or running right into an object a la Imperial Bike Scouts in Return of the Jedi.) They often have sweet weaponry that you can fire as you streak towards your enemy, meaning that between your firepower and speed you will often outdo them easily. And like the Eldar of Saim-Hann and the Ork Speed Freakz, you can get that rush from going really, REALLY fast.

Eldar Jetbikes

Warning. Always in large numbers. Even bigger if Saim-Hann.

As you should know, the damned knife-ears are the only faction other than the Necrons to field Jetbikes en masse. Possibly because it is due to the fact that unlike some other people they actually try to preserve and use their technology to best of their expertise. They are used by not only Craftworld Elfdar but also the Harlequins and even the Dark Eldar (Albeit at lesser quantities and amounts to the point it is not even in their armory). These sleek and elegant craft, capable of high speeds and extreme maneuverability, are testament to the Eldar's mastery of anti-gravitic technology, much to the amazement and jealousy of the Adeptus Mechanicus. On the battlefield they are commonly used as skirmishers, scouts, and fast-response units.

Contained within the body of these Jetbike are powerful anti-gravitic motors, allowing the craft to attain such great velocity that without an Eldar's enhanced reaction speed it would be lethal to ride, so for all you Guardsmen out there who will try to sneak up on one and do a wheelie. Please don't. Through subtle manipulation these motors can also send the bike into a steep climb or sharp dive, though its shape naturally inclines it towards level or upward flight. Long, curved vanes on either side of the bike allow for incredibly sharp mid-air turns. Like most Eldar technology the Jetbike is mentally attuned to the natural psychic abilities of the Eldar so even if you were to ride one without getting your ribs crushed by XTREME! g-force, if you aren't a Psyker then consider it a dud. Anyways, these psychic mumbo-jumbo works via small patches of psychotropic crystals, within the bike's handlebars and the rider's gauntlets, allowing the rider to control the craft through mental commands. For an Eldar to master the Jetbike is an exhilarating challenge that can take years of practice to reach their full potential, but those who do are said to build a rapport with their steeds comparable to the horsemasters of legend.

Jetbike armament consists of twin-linked Shuriken Catapults, although special craft known as Shrieker Jetbikes instead mount a single Shuriken Cannon. Jetbikes are most commonly used by Guardian Jetbike Squadrons for a number of battlefield duties, particularly the Wild Riders of Saim-Hann. The only known Aspect Shrine dedicated to the Jetbike are the Shining Spears, a rare group found on only a few Craftworlds, but they are so in tune with their steeds that they can perform complex maneuvers with but a single gesture. As well, many war-leaders of the Eldar are also known to ride into battle on Jetbikes, including Farseers, Warlocks and Autarchs.

Imperial Jetbikes

Unfortunately due to a certain chapter and a certain adept, the glorious remaining Jetbikes have been hidden deep inside the secret vault of secrets. Just don't tell the Blood Ravens about this.

As with everything cool and deciding humanity needs to be fucked from every angle possible, GW has decided the Imperium doesn't need Jetbikes and has thus made it a lost technology to the Imperium, dumping your proud marines back onto tired (pun intended) old bikes.

Boo!

To rub grimsalt in the wound, GW has done two things. First of all the pesky Eldar have access to Jetbike/Jetbike-like rides, so they can fly around blowing raspberries at you. (I guess Marines do get land speeders but that is like a car to the motorbike that is the Jetbikes. Instantly not as trendy). So if the enemies of the Imperium having it wasn't even, there is the second thing. During the Great Crusade the Imperium DID have Jetbikes. Only in small numbers but growing and the Legiones Astartes used them as dedicated fast response units and to pick up chicks (check out this motor baby!).

But the Imperium is ridiculous at keeping back-up copies of all its technical data and they just....forgot or lost the means to make Jetbikes, a gross example of the failure that has continued to haunt the Imperium and Imperial players to this day. (Heck, I wonder if the Imperium is even aware now they used to have Jetbikes.....hmmm).

The only remaining known one is used by the Master of the Ravenwing of the Dark Angels Chapter, Sammael, who uses it to hunt Fallen Angels HERETICS FROM THE NINE TRAITOR LEGIONS. Like the rest of the Dark Angels, he is a dick who doesn't share the fact outside of the chapter he has a working Jetbike. Of course if you thought that would mean the Imperium could, you know, start making Jetbikes again for it's armed forces, think again. The Adeptus Mechanicus is so anal about anyone touching technology they would probably hide it in a museum technobrothel somewhere to gawk at on some stand have sex with.

Then again, it wouldn't be out of character for the Dark Angels to have secretly collected a bunch of jetbikes (or even an STC) and lied about it to the rest of the Imperium, as Sammael's jetbike has been working surprisingly well for many centuries despite being dragged into one warzone after another, not to mention the numerous times it's been seemingly destroyed, only to reappear without a scratch on it...

Basically the Imperium has no Jetbikes left because everyone who might have access to one is a greedy superstitious twit who would rather hoard their goodies then share. And who are the victims? WE ARE because we don't get to have Jetbikes in our armies..... unless you play Horus Heresy, where the flying dildos Jetbikes are your standard Fast Attack unit. Doesn’t this mean the traitors should have Jetbikes in huge quantities?

• 

  Sammael's Pimp Bike

And then...Custodes!!!

In a move that surprised exactly nobody, the Emperor’s personal pimps have now got access to Jetbikes. Either they were locked up in the palace with the rest of their gear, or they saw Sammael on his when they got off their asses and pulled a Ferrari Mechanicus in complaining. Either way they are now riding around on giant golden eagles and holding huge jousting spears a la knights in shining armour. They also get Hurricane Bolters as standard. The older Gyrfalcon pattern is even better and starts out with a Lastrum Bolt Cannon.

Star Wars

Speeder Bikes are fast moving vehicles that can reach as high as 10 meters off the ground. They've been in common use by most developed factions in the galaxy, and have been for quite some time. The notable exception is the Confederacy of Independent Systems who only used them for a limited number of officers due to the nature of their soldiers, and even then they had the STAP which was essentially a speeder bike you stood on. Typically used for reconnaissance, probing enemy defenses, chasing down intruders, or in one particularly hilarious example from the (now non-canon) clone wars cartoon, literally jousting against enemy walkers.

A specific type of speeder bike that was tuned more for raw speed and coolness than secondary things like rider safety is the Swoop Bike. Swoop racing is popular throughout the galaxy, from the Core to the Outer Rim, and only became more popular when pod racing was outlawed. This popularity stems from the fact that Humans were physically capable of competing at high levels. Han Solo was a swoop racer in his youth. Swoop gangs are common outlaw organizations.