The X-Bow, More Than Four Wheels

When the Austrian motorcycle maker KTM wanted to add a sports car to their lineup, they went to Audi, then Dallara, to find technical support

KTM is an Austrian motorcycle company. Originally it produced only off-road bikes, but now it also makes ATVs / quads and road orientated machines, all focused on the enthusiast end of the motorbike market—there are no retro-cruisers, scooters or large screened tourers in the KTM range.

In the summer of 2005, this hardcore motorbike company, along with their design partner of 14 years, Kiska, embarked on a research project, which within 6 months saw them committed to adding a sports car to their range. This is the unique story of how that car, the remarkable X-Bow, came to be.

Following the launch of the KTM X-Bow at the Geneva Motor Show, we spoke with Stefan Pierer, CEO of KTM, and Gerald Kiska CEO of Kiska, and heard how this extreme, minimalist, mid-engined sports car was born of a project that originally looked specifically at a road-orientated quad-type bike for the European market.

Initiated in the summer of 2005, by August the Kiska design team realised that the high centre of gravity inherent in the quad configuration meant that this type of product would lack sufficient stability to be safe enough for high speed road use. The brief was redefined to be: as minimalist as an ATV / quad, to have the acceleration of a motorbike, and to have the driving dynamics of a race car. Under Sebastian Stassin, head of Transportation Design at Kiska, the team began to sketch designs which, whilst clearly motorbike-like in their aesthetic, had similar proportions to a contemporary small mid-engined sports car such as a Lotus Elise. There were some alternative Beach Buggy-style proposals and ideas using aluminium frames, but the team quickly settled on an initial direction by Martin Petersson that featured a carbon fiber tub and the motorbike-style exterior with floating panels.

In parallel to these formative steps taking place in the Kiska studio in Austria, some senior Audi engineers with a passion for motorbikes had been in talks with KTM about possible collaboration in some new project. They were introduced to the X-Bow project in September 2005 and immediately took a central role in powertrain, body structure and other technical issues during the early development phase—to such an extent that for the Kiska design team "it was an open scenario at this stage—it could have been either an Audi or a KTM, they were involved in all aspects of the vehicle's engineering—way beyond the engine" as Stassin explained to us.

In December 2005 the Audi engineers reluctantly recognised that the X-Bow concept was too far divorced from their brand to be produced as an Audi. They moved away from a central technical role, but maintained their support for the powertrain to the extent that it will be possible to service an X-Bow at selected Audi dealerships.

At this stage, in the spring of 2006 and with a full-size clay developed on a technically feasible package, the Kiska team approached the Italian racing car company, Dallara, to replace Audi in the role of technical support. With extensive experience in developing F1, F3, sports endurance and Indy cars, and specific production car experience with the use of carbon fiber in the Bugatti Veyron, Dallara was a perfect fit. Initially they were alarmed by the form of the KTM car which, with its open cockpit and many faceted panels, was inherently a design with poor aerodynamics: "When we presented it to them they got pretty scared I have to admit!" Stassin told us.

However, once Dallara realised the objective for the X-Bow was to deliver a fun, recreational sports car that focused on handling rather than ultimate speed, they were able to focus on improving down-force to maximise cornering grip. Dallara then took Alias-produced surface data from Kiska designer Peter Stiller, put it into their bespoke aerodynamics software and found the X-Bow's down-force to be inherently strong with just the balance between front and rear needing further development.

To develop the form, a 40% clay model was produced at Kiska in Austria, which was then digitised and milled on a rapid prototyping machine at Dallara in Italy for aerodynamic testing, with results fed back directly to Austria. Here, the design was evolved in clay and then wired back to be milled again in Italy. This iterative process happened 5 times from May to September when the design was finally signed off.

In parallel to the aerodynamic and final form development, Kiska was developing a production-feasible design that met European homologation requirements that are clearly geared to mass produced sedans. For a company that until then had only produced motorbike designs and initial sketch proposals for cars, this was a steep learning curve. Over the summer of 2006 Kiska also worked with suppliers to develop smaller components, including the innovative steering wheel that Petersson designed, which includes controls for horn, lights, and indicators not present on the similar Audi endurance racer steering wheel that their supplier Megaline had previously developed. And whilst the extrovert surfacing of the car is the most obvious quality of the design, it is the resolution of these details that sets the X-Bow apart from almost all other low volume car designs.

"It's not a kit car—this was one of the main rules we want to apply" Stassin told us. Clearly Kiska, KTM and Stassin mean to differentiate themselves through design—particularly design detailing—from such cars as the Caterham Seven and Donkervoort, and even the Lotus Elise and Ariel Atom, by not having any obvious carry-over design details: the lights with their bespoke framing of Hella units are further testimony to this.

But Stassin is also keen to emphasise that Kiska's attention to detail goes beyond the X-Bow itself and extends to the design of the KTM Geneva show stand, the press information, the promotional movie and other marketing material—all part of what Kiska term IDD: Integrated Design Development.

Clearly, the design development of X-Bow is a rare project, where one design team takes a project through from conception to realisation with plenty of autonomy, without having to contend with typical factors such as heritage, external engineering groups, client marketing department, sibling or predecessor products. And it is this, combined with the potency of the design, that  makes the X-Bow story quite unique. Stassin sums it up well:  "I often say that it is the kind of project that if you do it once you should be very happy".

Update: KTM announced yesterday that production of the X-Bow will now start in early 2008 with Magna Steyr, instead of the company's original plan to wait until completion of the pilot run of 100 cars by Dellara before committing to series production. These initial 100 cars will still be produced, but with 600 orders already, KTM will strive to reach maximum production capacity of about 1000 in 2008 and expects to continue with a volume of more than 500 units.

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