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My Bikes

Motorcycles developed with the contribution of Klaus Nennewitz


ATK 604 Restyling 1991

ATK Motorcycles Los Angeles, California USA

The 1991 model was based on the 1989 ATK 604, the first Fourstroke Motocross bike with elctric starter developed by the founder of ATK, Austrian engineer Horst Leitner. This rugged and extremely reliable bike was perfect for Offroad riding in the deserts of California and Mexico. The task consisted in the design of a new fueltank and sidepanels during springtime 1991. In June 1991 I rode an ATK 604 together with two of the best American Desertracers, Bill Diaz and Detlef Herrmann, to 10 th position overall in the Baja 500 Desertrace in Mexico.

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Malaguti F 12 Phantom 1992/93

Engines Engineering Bologna Italy 1992/93

The Malaguti F 12 Phantom 50 cc Scooter founded a new generation of sportive, "Racing-replica" Scooters together with Aprilia's SR 50 featuring big wheels. Cooperation during the development as modelmaker, mechanic, design engineer. Preparation of the engineering thesis: “Conception, interpretation and constructive elaboration of a Scooter-frame as a part of a complex vehicle development-process”

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Aprilia RX 125 1994

Aprilia SpA Noale Italy 1994

When I arrived in Aprilia in January 1994 I was given the task to design the frame of the 1994 model with the help of a CAD-system. After a few months I switched to the RS 250 project. I had the chance to ride the production bike on track during the 1994 Valli Bergamasche Enduro World Championship near Bergamo in deep mud. Power was sufficient but the steering of the bike was kind of stiff and it wasn't really built to perform on a WEC track...

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Aprilia RS 250 1994

Aprilia SpA Noale Italy 1994

In summer 1994 I was assigned to the taskforce of this project to ensure the production start in fall 1994. I took care of the design of some components and gained the first experiences in project management in Aprilia leading the catalized version for Germany to production. I loved this project and rode the test bikes all over the Dolomites during the winter 94/95 including gravel roads around Garda lake which caused me an admonishment by Aprilia testrider Claudio Pellizon who always found some pebblestone in the fairing's keel.

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Aprilia Pegaso 650 1996

Aprilia SpA Noale Italy 1995

In spring 1995 I was charged with the technical management of the 1996 Pegaso 650 which consisted in an update of the existing model to the new emission- and noise regulations. Endless drive-by-tests in an industrial area near Noale helped to determine the noise sources of the bike. A new exhaust system was developed and modifications to the airbox, carburators and other components of the bike were realized. The picture shows the comparative testride in the Dolomite mountains with the old Pegaso, the BMW F 650 and the protoypes of the new Pegaso Cube 650.


Aprilia Pegaso Cube 650 1997

Aprilia SpA Noale Italy 1995/1996

In summer 1995 I took over the project of the new Pegaso 650 Cube at a point when the final design was approved and the important choices had already been made. At first glance it seemed an easy project with new geometry, new bodywork and a revised frame. But during the preseries in spring 1996 desaster struck in the shape of vibrations. Nightshifts, shortened summer-vacation and unlimited dedication to resolve the problem from all colleagues helped to determine a different layout of th eraer subframe as the cause of vibrations. Just 4 weeks before production start the castings of the frame and other main components were modified to guarantee SOP as planned. The picture shows my personal preseries bike # 44 after the return from a 6.000 km tour in Scotland in summer 1998.

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Aprilia ETX 125 1998

Aprilia SpA Noale Italy 1997

During the Pegaso Cube 650 1997 project the powerlimit of 15 HP for the 125 cc bikes was established and KTM had just presented their 125 LC 2. Somebody in Aprilia came up with the idea to transform the RX 125 in a Softenduro, but nobody in the company was really convinced of the project and it was extremely delicate to tame the Rotax 125 cc race-engine. Endless discussions with Rotax and pressure to meet the cost targets keeping on the other hand all the features of a sportive Aprilia transformed the project in an unpleasant experience nwithout commercial success.


Aprilia SL 1000 Falco 2000

Aprilia SpA Noale Italy 1998/1999

After the deception of the ETX 125 I must be grateful for the confidence I was given when put in charge of the SL 1000 Falco. It was the time when bikes like Honda VTR 1000 and Suzuki TL 1000 S became quite popular as “Sportlight” bikes for the road. We pointed to arrive with such a proposal just one year after the launch of the RSV Mille in 1998. This project was really the first one I followed from the very beginning all the way to the production launch including the development of the design together with my friend, the Scotsman Martin Longmore who had designed the Audi TT and the BMW F 650 previously. A part from the usual stress to meet all the targets (financial, timing-schedule, performance and quality) the project went quite well except….
It was an unspoken myth in Aprilia that new bikes were not allowed to touch the ground of the production-facility on a Friday. So I personally stopped the production line on Friday afternoon even if I had no authority to do so…resulting in a big reprehension from the production manager. Together with a few guys from the team, we showed up on Saturday to finish the first bike…
The picture is taken during the final, 8.000 km testride in summer 1999 in Romania. The commercial success of the SL 1000 Falco could have been  better but the bike won the comparison test of the Sporttouring bikes against all the competitors in the fall 1999 edition of Europe's biggest motorcycle magazine, MOTORRAD from Germany.

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Aprilia SpA Noale Italy 2000/2001

After the SL 1000 Falco project a reorganisation in R&D took place and I was promoted to be head of one (of the 2) motorcycle platforms. The crisis in the company was already tangible and it had become really difficult to kick off new projects. In 2001 we worked on a new family of bikes with a new V 2 engine to compete with the Honda Hornet 600 and the Suzuki SV 650 in the very popular category between 600 and 800 cc, but it was impossible to reach consensus, especially after the twin tower attacks in New York on September 9 th 2001 that shook the motorcycle markets.

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Aprilia Tuono 1000 2002

Aprilia SpA Noale Italy 2001

In fall 2001 I was really bored and hadn’t even noticed that the design department under Gianfranco Frison was working on 2 proposals for the Motorshow of Bologna in December 2001: the Shiver 1000 of Maurizio Carbonara and the Tuono 1000 by Giuseppe Ricciuti. The first thing I saw of the Tuono was the golden frame in the machine shop, to be honest I found the colour quite awkward for a motorcycle frame…
When I came back from the presentation at the Motorshow 2001 (together with the Aprilia Cube, the first Italian Moto GP bike…) we set up a prototype in one week. My mechanic Stefano came back from the first ride and sat down at my desk, still dressed up for the road, with a big grin on his face: “You must test the bike, you will not believe how well it works!”
And he was right! We pushed the bike to production within 5 months in a team of 4 people, just digging, night and day, without ever looking up. The rest is history...
I am often called “Il papa della Tuono” which is right only in a certain percentage. I was lucky to inherit a very healthy and well-done project, the RSV Mille from the team of Marino Carlesso, Mariano Fioravanzo, Claudio Pellizzon and colleagues. Without their continuous strive for perfection during the very first RSV Mille, the Tuono would never have been so successful.

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Aprilia Tuono 50, 125 and 1000 2003

Aprilia SpA Noale Italy 2003

After we had put the Basic version of the Aprilia Tuono 1000 to production in fall 2002 our team was bored again. New managers had arrived from the automobile industry and it was always more difficult to kick off new projects. Marketing had decided to launch the Tuono-concept also for the small 50 and 125 cc bikes, so our team took over the development of 3 projects for spring 2003: 50, 125 and 1000 cc.
The Tuono 1000 R from that year is in my personal opinion the most beautiful Aprilia every built up to that year. Massimo Temporali won the Italian Championship for Naked bikes that year.
After a long and final testride that led me to Elba, Viterbo and the Marche together with my friend and journalist Lorenzo Cascioli I had accomplished my duty in Aprilia. The Aprilia World Meeting end of May 2003 was a beautiful event before the final curtain went down for me with a ticket to Barcelona in my pocket…


Derbi Senda 125 2003

Derbi Nacional Motor Martorelles Spain

When I arrived in Derbi near Barcelona in July 2003, the protoypes of the Senda 125 were already assembled and it was my first job (among others on the 50 cc lineup) to complete the industrialisation of the project. There was a great team in Martorelles but we were missing the know-how that was available in Aprilia regarding the load-spectrum for the chassis. I ended up testing the prototypes on the gravelroads on top of Barcelona during the weekend and every Monday I came back with another broken part…but in the end we fixed everything just before delivering the first bikes to the dealers-right on time!


Derbi DRD Pro 50

Derbi Nacional Motor Martorelles Spain

Derbi was very successful at the beginning of the new Millenium with 50 cc Offroad and Supermotard bikes, especially in France and, of course, in Spain. The concept of those bikes with steel frames was quite outdated so we decided to modernize the top line of our bikes for youngsters with a completely new concept featuring an aluminium frame. The new bike had an outstanding handling and featured the new 50 cc 2-stroke engine developed by Derbi. The DRD 50 Pro was on top of the category in Europe selling better than expected. The internal racing team of Derbi won the 80 cc Motocross Endurance Championship of Catalonia in 2006 on this bike!


Derbi Mulhacèn 659 2006

Derbi Nacional Motor Martorelles Spain

Since my arrival in Derbi in 2003 we had managed to turn some heads with the modernization of our product lineup and the new 125 cc bike. In spring 2004, Derbi’s CEO asked me to think about a showbike for the 2004 Intermot motorcycle show in Munich, Germany in fall. I had been waiting for this opportunity for years! Already in Aprilia I had made studies to build a Flattrack bike for the road, I even went to visit the mechanic of the American National Flattrack Champion Chris Carr, Kenny Tolbert, in Texas to evaluate the construction of a prototype in December 2002. I traced the layout of the bike which I had in my head and Derbi’s designer José Gonzales did an excellent job for the style of the show bike. We managed to finish the prototype just one day before the start of the show and the result was overwhelming! Finally, in March 2005 we were given the OK to develop the production version of the protoype. With a very determined team, we managed to meet the SOP in May 2006, after just 13 months of R&D work thanks also to the unconditioned support from the suppliers of this project.
The Mulhacèn 659 weighed 20 kgs less than the competitors with the same engine and provided an unmatched handling on tiny roads.
Nevertheless, our brand was not strong enough to promote the biggest bike that was ever produced by a Spanish motorcycle company. After almost 500 bikes built, the production was stopped. In an attempt to recover the investments we set up a street version “Nieto replica” with 17” tires, but this was not the real DNA of the Mulhacèn.

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Derbi DRD 125 2007

Derbi Nacional Motor Martorelles Spain

In early 2006 we started to develop the new 125 4-stroke engine together with Piaggio using cylinder and –head of the 125 cc Scooter. A completely new engine housing was designed resulting in one of the smallest and most powerful engines of the 125 cc category.
The Derbi DRD 125 Supermotard and Enduro project was the first completely new bike to host this powerplant. An enormous effort was made to lay the grounds for the new 125 cc platform of the future for the Piaggio group. Today, 14 years after the launch, the basic concept and components of the DRD 125 made by Derbi is still produced under brands like Aprilia, Mondial, Zündapp, UM Motorcycles…

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Derbi Mulhacèn 125 2007

Derbi Nacional Motor Martorelles Spain

Contemporarily to the DRD, the Mulhacèn 125 was launched in summer 2007. This bike featured a different technical platform making up for an extremely easy to use motorcycle for every day. Like the DRD 125, also the platform of the Mulhacèn continues to be produced under different brands like Mondial, UM Motorcycles and others, 14 years after the launch!

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Derbi Terra Adventure 125 2008

Derbi Nacional Motor Martorelles Spain

With the Derbi Terra and the following evolution “Adventure” in 2008, the company from Catalonia had definitively reached a position as one of the main players in the small size motorcycle segment in Europe. This bike featured an elevated riding comfort and superb handling together with a high load capacity.

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Yamaha XT 540 Rallye 2010

Italy, Germany 2010

After meeting the Dutch hero Henno van Bergeijk who finished next to last in the 2006 Dakar Rallye in Africa on a Yamaha XT 500 I was obsessed to design and to build a professional Rallyebike based on the mother of all 4-stroke Offroad thumpers, the XT 500. The plan was to build 3 bikes for the 2011 edition of the Dakar. The project started in April 2010: the frame was reinforced, new suspension front and rear including new wheels and brakes were added. Fabio Montanari from Varese, Italy, who built the tanks for the factory Dakar-Cagiva’s in the early Nineties, designed and built 3 fuel tanks, the airbox and the bodywork out of aluminium sheets. The bike was completed in the workshop of XT 500 specialist Meinold Müller from Beverungen in Germany. Just one day before the start of the 2010 Breslau Rallye in Poland, the Rallye XT was registered with no time for testing. 90 riders participated in a gruelling edition of the toughest Offroad Rallye in Europe. The bike held up without mayor mechanical issues and I made it across the finish line in 16th position, in the classification of teams we even made it to the podium in 3rd position!
Potential sponsors for the Dakar pulled out of the project so the project was put on hold after the successful participation in the Breslau Rallye.

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+ 500 cc Scooter of European manufacturer

Ricardo Engineering Schwäbisch Gmünd Germany 2011/2012

Chief Engineer and taskforce manager during industrialization of the engine for a European manufacturer of 2-wheelers. Projectmanager for the evolution of the powerplant for further applications

Malaguti F 12 Diplomarbeit revised

+ 300 cc Scooter of European manufacturer

Ricardo Engineering Schwäbisch Gmünd Germany 2012/2013

Chief Engineer and Projectleader during the conceptphase of a new engine for an urban vehicle. Coordination of international project groups.

My Bikes: Fertigkeiten
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