Motorcycles at their most basic are already pretty manly. So when rogue lunatics decide to soup them up with increased power and/or jet engines, it's like putting laser gun goggles on Batman. To prove the theory, we've found six bikes that kick more ass than Jet Li with his hands tied behind his back.

1. Jet Bike
Every other "most powerful" bike on Earth is built by pansy companies who worry about "street legality," "not exploding" and "messing up the pink ribbons in their curly hair." Ron "Mad" Laycock moved to the appropriately named city of Darwin after Cyclone Tracy, clearly deciding that if there was ever going to be another natural disaster he'd be the one to cause it.

The what-we-must-call-a-bike-because-DeathOnWheels-isn't-a-proper-noun-yet sports 3,800 horsepower from an actual jet engine, which Ron adapted by attaching two wheels to it. He also included some handlebars, presumably for something to hold onto. That's why we're including the "Mad" -- normally people don't get to pick their own nicknames, but, when you simultaneously dare physics, engineering and aeronautics to kill you, we'll call you whatever you want and salute you while doing it. This bike could only be manlier if it was specifically designed to catch on fire.

2. A Bike Specifically Designed to Catch on Fire
Presumably bored waiting for internal combustion to grow a pair and come get him, Mad Laycock built the Fire Burnout. This lunatic Chevy 327 V8 can stay continuously on fire for a quarter of a mile. At this point, it's clear that Death just enjoys watching Ron too much to come get him.

3. Henry Brody's 1929 Douglas Motorbike
The other bikes on this list are made manly by power or engineering. Henry Brody's is made manly because it carries Henry Brody, and that's more man than a lumberjack convention.

Henry Brody is 76 and the U.K. Veteran Class Motorcycle Sprint Champion. "Veteran" refers to the age of the bike, not the rider; Henry regularly annihilates people almost 60 years younger on the quarter-mile track. The bike itself is over 80 and probably hasn't had as many parts replaced as its rider.

Henry has one eye, an artificial hip and a pacemaker, and says, "'Once you give up and you're just sitting around at home all day, life's over really." Well done. You've just been made to feel bad about using the Internet by a speeding septuagenarian.

Further proof that Brody is really an escaped comic-book character: He gets help maintaining his classic motorcycle from Bill Douglas, the grandson of the founder of the bike's original manufacturer. He probably spends time between races solving crimes and catching drug dealers.

4. The Shark
At the opposite end of the age-spectrum is the GERG Group's SHARKER, built with carbon-fiber, electro-everything and a ludicrously aerodynamic shell. The bike can accelerate from 0 to 60 mph in four seconds, before it keeps right on going up to 175 mph. That's about 250 feet a second.

You'll notice that it looks like a hungry shark, comes only in black and red, is purposefully built not to care what you think and will turn your genitals into powder if you slip off your seat. If this bike were any manlier it would have starred in "Commando."

5. World War II Fighter Sidecar
One man achieves the impossible: a sidecar that doesn't legally reclassify you as a girl when you sit in it.

It's actually built from a WWII German fighter plane, and it doesn't look like some war nut's pet project. It looks like MacGyver traveled back in time to help Steve McQueen make an even greater escape. This thing would have jumped the first barbwire fence, fired its engine, soared over the second, then turned around to bomb Hitler.

6. The Cruise Missile With a Seat

Even the jet-bikes above can't compare to this because, demented as they are, at least jets are designed to be survivable. This testament to testicles uses a J402-CA-702 Model 373 Turbine Engine. Assuming you're not a Borg, that's U.S. Army code for "Unmanned Drone Engine."

It's actually the more powerful model and was never intended for human use. Double-never-intended to have a saddle fitted by the world's bravest man and kicked in the ass until it broke 200 mph in under eight seconds.

But don't worry, guys. That whole Harley "putt-putt-putt" thing is cool, too.