Dodge Tomahawk
The Dodge Tomahawk was a non-street legal vehicle introduced in 2004 by Dodge at the North American International Auto Show, as a one-off concept, and later that year, DaimlerChrysler announced they would sell hand-built reproductions on order. The Tomahawk attracted significant press and industry attention for its striking design, its outsize-displacement, 10-cylinder car engine, and its four close-coupled wheels, which give it a motorcycle-like appearance. Experts disagreed on whether it is a true motorcycle. The retro-Art Deco design's central visual element is the, V10 SRT10 engine from the Dodge Viper sports car. The Tomahawk's two front and two rear wheels are sprung independently, which would allow it to lean into corners and countersteer like a motorcycle.
Dodge press releases and spokespeople gave various hypothetical top speeds ranging from to as high as, which analysts thought were probably calculated with horsepower and final drive ratio alone, without accounting for drag, rolling resistance, and stability. These estimates, and the more conservative a designer suggested could be possible, were debunked as implausible, or physically impossible, by the motorcycling and automotive media. No independent road tests of the Tomahawk have ever been published, and the company said that in internal testing it was never ridden above. The Tomahawk was sold through the Neiman Marcus catalog at a price of US$555,000, and as many as nine are thought to have been sold. As they were not street legal, Dodge said the reproductions were "automotive sculpture", "intended for display only" not fully operational.
Industry observers said the Tomahawk was a resounding success at one-upping rivals and taking the trade show spotlight, and was a branding and marketing coup, generating media buzz and sending the message that Chrysler was a bold, ambitious company, unafraid to take risks.
Inception
The idea for a Viper-engined motorcycle started with two lower-level Chrysler Group employees, Bob Schroeder, a design office modeler and motorcycle rider, and Dave Chyz, vehicle build specialist and drag racer. According to designer Mark Walters, the question asked was, "What if we had a Viper engine and a Champion chassis? Something like a Boss Hoss", resulting in an engine displacement five times a typical Harley-Davidson. The low-volume Boss Hoss motorcycle is built around a Chevrolet V8, and the largest-displacement mass-produced motorcycle is the Triumph Rocket III, neither anywhere close to the Viper engine. The only motorcycle with a displacement in the Tomahawk's league uses the same V-10 car engine, the one-off 2009 Millyard Viper V10, a bike created to rival the Tomahawk after Allen Millyard was underwhelmed by a Tomahawk speed run at the Goodwood Festival of Speed in the UK.Schroeder and Chyz took the proposal to Senior Vice President of Design Trevor Creed, who initially said, "we don't build bikes" but still allowed some design sketches to be created, which were "mind blowing" enough to bring Creed on board. They eventually took the idea to Freeman Thomas, DaimlerChrysler VP of advanced design, who assigned Mark Walters to join the effort. Thomas suggested using two front and rear wheels because a single wheel would look thin next to the unusually wide engine, inspired by the four-wheeled light cycles in the film Tron. Walters anticipated howls from bikers that this would make it not a motorcycle, but he felt uniqueness was more important, and imagined the appearance with only a single wheel in front of and behind the engine would have been visually unbalanced, saying he would like to see it made that way for comparison. By the spring of 2002, Walters had prepared a full scale design presentation, with sketches along a wall and a borrowed Viper engine resting on an engine stand with two wheels placed fore and aft as a visual aid. This was presented to Chrysler Group COO, Wolfgang Bernhard, and CEO, Dieter Zetsche, who gave their immediate approval.
Design
The design was the work of Chrysler staff designer Mark Walters, who built the vehicle around the Dodge Viper V-10 engine. Once approved by Bernhard and Zetsche to build not just a full-scale mockup, but a running, workable concept vehicle, the design and fabrication process took six months. The engineering, as well as the fabrication, was outsourced to RM Motorsports, a Wixom, Michigan, specialty shop that fabricates one-of-a-kind parts for rare and vintage race cars. Walters said Kirt Bennett at RM handled the task of making Walters' sketches a physical reality that was mechanically sound. Walters' early sketches had a front suspension that looked something like an Elf-Honda racing motorcycle's hub-center steering, from which RM designed a new, patented front- and rear-swingarm suspension that allows both parallel wheels to lean together, keeping all four in contact with the ground and allowing countersteering. The Tomahawk was intended, unlike many concept vehicles, to be a "functional runner" that "had to work" as well as have a finished appearance, since the mechanical parts would be exposed to view.The V-10 engine needed several design changes. To position the engine lower to the ground, the lubrication system was changed from wet sump to a dry sump type, moving the under-engine oil sump to a tank located in front of and to the left of the engine. The car-style single radiator out in front of the engine was changed to two smaller radiators and fitted into the V-shaped space above the engine, where cooling air is force-fed using a belt-driven fan sourced from a Porsche 911.
Suspension
The Tomahawk has an independent suspension on all four wheels designed to allow the rider to countersteer and lean into turns like a tilting three-wheeler. There is a hub-center steering style swingarm connected to the outboard side of each of the two front wheels, with a steering link connected to the handlebar shaft. There is very little lock-to-lock steering range, only about 20° on either side of center, so the turning radius of the Tomahawk is large; "only a little tighter than an SR-71", said Motorcyclists Jeff Karr. A low center of gravity, accomplished by situating the engine as low to ground as possible, is intended to provide greater control at low speeds, and a low saddle allows riders to place both feet on the ground when stopped, for greater stability. The two rear wheels also each have an independent swingarm, but on the inboard side, along with an inboard chain drive for each wheel. The rider can engage a rear suspension lock, which hydraulically holds the two wheels' relative positions, letting the vehicle stand on its own, without using a side stand.According to computer imaging, the suspension would allow a lean of up to 45° with all four wheels maintaining contact with the ground before one of the swingarms contacted the ground, although attempting to actually corner at such extreme angles is not safe given the Tomahawk's weight. Test rides for the purpose of photographing the Tomahawk in action revealed that there were still stability issues to be worked out, given that it rides, "like two motorcycles riding in ultraclose formation, coupled with the weight of three and the horsepower of four," in Karr's words, meaning that, "some disagreement is inevitable." RM Motorsports's Bud Bennett said the 45° lean system worked well and was in fact stable, quashing rumors that any test riders had been thrown from the Tomahawk, and that the only issue was the original design's limited 18° handlebar turning radius, making sharp turns impossible. In 2003, RM Motorsports had been working on designs for versions with wider handlebars allowing more control, and two or three wheels instead of four, making a street-legal Tomahawk conceivable. Bud Bennett said that, at RM, they thought the narrower, limited-range handlebars and unnecessary two front wheels instead of one would not function well, but at the time the design was "just a concept" with no anticipated customer demand, and as a concept vehicle, the Tomahawk did "everything it was supposed to do, which is to push the Dodge name and to celebrate the Viper engine."
Fabrication
Bennett's team at RM custom-milled the Tomahawk components from blocks of aluminum. Under the seat are two alloy pieces that began as billets that are machined down to each, and polished to a mirror finish. Details like hand levers and the twistgrip use needle and ball bearings.Detroit Auto Show debut
The Tomahawk debuted at what Automobile Magazine called the high point of a period of increasing extravagance at the Cobo Hall Detroit Auto Show that began with the expansion of the show in 1986–1987, leading to the splashy debuts of ever larger and more powerful cars and trucks, such as the Hummer H2 in 2000 and the Ford GT40 in 2002. Newsweek described the period as a "horsepower arms race".The 2003 show had the largest ever attendance, 810,699, and the limits of concept excess were pushed further with the 7.0L V-10 Ford 427 Concept, which had a V-8 hastily expanded to 10 cylinders in response to rumors that Cadillac was going to show a V-10, only to be outdone when the rumored V-10 turned out to be the Cadillac Sixteen, with a claimed V16 that could shut down 8 or 12 cylinders at a time to save fuel. Yet even these monsters would be upstaged by an even more unexpected debut, Dodge's V-10 motorcycle, unveiled the day after the Sixteen. In response, GM executive Bob Lutz, who himself had helped conceive the Viper in 1988 when he was at Chrysler, was asked where his 1,000 hp V-16 motorcycle was, and he answered, in the wry spirit of the question, that he had none, pounding the table and saying, "Rats, outmaneuvered by Chrysler again!"
AutoWeek named the Ford 427 "Best Concept" and the Cadillac V-16 "Best in Show" for 2003, and the editors said they wished they had an award for "Best Automotive Sculpture" to give to the unexpected motorcycle they found so likable. The jury of 35 journalists of the North American Concept Vehicle of the Year chose the General Motors Hy-wire over the Tomahawk for the 2003 Specialty Concept Vehicle of the Year award. The Tomahawk was remembered in 2014 by Automotive News as one of the "10 Most Memorable World Debuts". In the years after the Tomahawk made its high-profile entrance, the Detroit Auto Show became more modest in scale, and the automakers' battle to outdo each other with boundary-breaking dream cars faded in the years leading up to the 2008 auto industry crisis, and the more cautious recovery that followed.