Dodge's Four-Wheel Motorcycle! (The Tomahawk)

Popular Science ^ | April 2003 | by Dick Teresi

[vannrox]

500-300-200. That's horsepower, miles per hour and thousands of dollars: the oversize numbers for Dodge's 4-wheel Tomahawk "motorcycle" prototype (named for the cruise missile), which the company says it may bring to market.

Dodge's Four-Wheel Motorcycle! (The Tomahawk)

by Dick Teresi

The biggest news out of DaimlerChrysler this spring is not a sport-utility vehicle or a sports car. It's a motorcycle. A big, weird motorcycle.

The Dodge Tomahawk is auto erotica for the customizer and power freak. An enormous 500-horsepower V10 Viper engine sits on a billet aluminum body, each part a one-off custom design, machined to order. The exhaust note reminds us of a light aircraft's, with enough crackle to rattle windows.

A noticeable departure is the four wheels. OK, a four-wheeled motorcycle is an oxymoron, but in this case the wheels are closely paired, giving the vehicle a motorcycle appearance if you squint hard. Dodge sees the four wheels as an advantage, noting that the bike stands up on its own. (Customers willing to shell out $200,000 should be happy to learn that they won't need to buy a kickstand as well.)

So what happens to this 4-wheeler when you lean into a turn? Similar designs have rolled up on just two tires when banking, then dropped back onto all four when the bike straightens out, sometimes with uncomfortable results. Thanks to an inventive suspension, all four of the Tomahawk's tires remain in contact with the road even when the bike is cornering. Yet it's no car. You lean and counter-steer, just like on a bike.



The bike's name was inspired by the Tomahawk cruise missile, and it may be equally ridable. Dodge first announced a top speed of 420 mph, then dropped that to "300+." DaimlerChrysler spokespeople proved unable to illuminate us further. Can we ride the bike to check the speed? we asked. "No." Can we talk to one of your company riders? "No." Can you give us some riding impressions? "No." Can we use your bathroom? "No."

Desperate for expertise, I called my brother, Joe Teresi, whose Easyriders Streamliner bike holds the world speed record: 322 mph on the Bonneville Salt Flats, set in 1990. Looking at photos of the Tomahawk, Joe was dubious. Dodge computed the Tomahawk's theoretical top speed only from horsepower and final drive ratio. Joe says this ignores other critical factors, such as frontal area and drag and the coefficient of tire friction to the ground. Joe offered Dodge the use of his Dyno-Drag, a motorcycle dynamometer/simulator, to ascertain the Tomahawk's top speed. When I relayed the offer to Dodge spokesman David Elshoff, he said, and I quote, "No." Elshoff did say Dodge would someday take the Tomahawk for a run at Bonneville.

Dave Campos, who was onboard the Easyriders Streamliner for the world record, predicted the Tomahawk wouldn't do well in the real world -- and that the rider would do worse. The Teresi/Campos bike was powered by two 91-cubic-inch Harley Shovelhead engines and enclosed in a fairing. The Tomahawk Viper engine is 505 cubic inches; the rider is exposed. Campos said he would be foiled by air resistance. At high speeds, "your back acts as a wing. It'll lift you right off the bike." Campos was also skeptical about the four-wheel steering, and said he doubted the bike would hit 200 mph. Still, he wishes the Tomahawk team luck at Bonneville. "Let nothing but fear stand in your way," he said.

Many bikes today are built for show, not go, and even if the Tomahawk never breaks 55, there are a lot of guys who'd like to trailer it to Sturgis or Daytona during Bike Week just to fire up that motor and drown out the Harley crowd. Or, as my brother says, "It's a nice engine stand for your Viper V10."

[Bikers4Bush]

Nice.

[m18436572]

KILLER !!!!!!!!!!

[Lysander]

I have 34-year-old "road rash" on my back to show why only young men would think about riding this type of death machine. I guess at 50-something I am still young! Gimme one.

[yankeedame]

That bike, WILL sell. It's cool, and all sorts of people have crazy money to throw around.

LOL! Well, you're certainly right on that point! So, we shall see...

[martin_fierro]

KEWWWWWL!

[Range Rover]

The "hubless" bike you speak of is one of Choppers Inc's creations - the Psycho Billy Cadillac

You can see a pic at:

http://www.choppersinc.com/projectbikes/assets/images/psychobilly_cadillac/wPsycho1.jpg

As for this dodge TRON bike, more of a styling exercise than anything. With no fairing, you probably couldn't get the thing over 150 mph with a rider. Pretty to look at, pretty useless on the road. It will end up in Jay Leno's garage next to a Stanley Steamer.

I'd trade the billet monstrostity for a vintage Indian, a Vincent, a Brough Superior or an EL Knuck any day of the week.

[Range Rover]

[boris]

"http://www.choppersinc.com/projectbikes/assets/images/psychobilly_cadillac/wPsycho1.jpg"

Thanks but that doesn't look like the one I'm recalling. And that wheel in the pic is the rear one. Do they have additional photos?

--Boris

[boris]

Oops. I scrolled down. It is definitely not the same. In the one I recall the tire rolls and the hub is stationary. On the rear wheel of this bike it looks as if the whole rear wheel turns; hard to tell. It looks cool because there is no apparent center of rotation.

On the bike I saw, it was the front (steering, unpowered) wheel that had a tire rolling in a raceway; I could not see how the stationary part was 'affixed' to the fork.

--Boris

[Range Rover]

I think I remember the one you're thinking of. If I find a pic, I'll post/link.

Was some form of leading link setup from what I recall.

[maxwell]

Holy CRAP. I dunno about that steering thing...

(And they won't even let ya use the john?)

Sure is purty to look at though...

[maxwell]

AWESOME.

[knews_hound]

V10 BUMP

[Charles Martel]

With the correct mods, it would outrun a 750 triple. The downside was that it couldn't corner worth a damn.

Heh, I've often toyed with the idea of putting that three-cylinder 2-stroke engine in a more modern chassis, just for kicks (and to put a finger in the EPA's eye). I rode an H1 some 20+ years ago, so I know exactly what you mean about the barely-there suspension and brakes. That front fork... ugh.

There was a neat trick I recall, something about a wiring connection that would kick the oil injection pump to full-volume, "limp-home" mode (my neighbors referred to it as the "mosquito fogger"). I can still smell the burning Castrol. :-)

[husky ed]

Isn't this the same company that put down conservatives earlier this year?

Let the FatArseChix ride their bikes, I won't.

[Lx]

I always ran under the theory that more oil than less was better. There were a lot of people running the injection pump as lean as possible to prevent fouling of those weird looking pinpoint electrode plugs. I always thought it better to foul plugs than burn bearings and scuff pistons, if you had a two stroke and didn't carry spare plugs and tools you soon learned to. If you had the one with the distributor, it was also wise to carry a spare coil for the reluctor. In fact, I think I still have both the A and B boxes for the ignition around here somewhere.

In my minds eye, I see the throttle cable going into the injector but I don't remember any electrical connection. One way to make the injector pump run full out was to pull the cable that went into the housing so it would open up the injector. Then again, for some reason, a lot of people removed the injector pump and mixed the gas and oil, I used to see this mostly on RD's. When they went to the three coil ignition, I think they changed the injector pump as well so it very well could have been electrically controlled.

Hell, I still carry a spare injection computer in one car and a complete distributor and computer in my older car.

Putting that engine on a shifter cart or a snowmobile, now that would be cool and give Christie Todd Whitman apoplexy.

[Charles Martel]

Putting that engine on a shifter cart or a snowmobile, now that would be cool and give Christie Todd Whitman apoplexy.

I actually saw a Kawasaki Triple on a shifter kart, and not too long ago. Didn't get to see it run, but I'll bet it was impressive. The owner of the kart had the Kawasaki gauge cluster mounted on his steering column... I could see that tach with the redline wayyyy over there to the right. I wanted a shifter kart *bad* for a month or so after spotting that triple-powered example, but even a used and abused kart chassis costs $$$ - it's cheaper to build a Toyota MR2 for SCCA SOLO competition. Now, if I could find a set of shifter kart chassis plans, I'd drag out the MIG welder and tube bender. All I've been able to find are basic "yard kart" plans. But yeah, it *was* cool!

[section9]

It's been done. First, it was Hollywood that can't come out with anything original and now Detroit is ripping off classic anime....

Yeah! That looked like Tetsuo's motorcycle in Akira. Dayyum! All it needs is the windshield and the decals.

Be Seeing You,

Chris

[Lx]

I used to know a guy who's company made shifter carts and they were waaay expensive. Then you had to add the engine.