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Three-wheeling on a twin

Sidecar racing can be an exotic and technically adventurous sport. Racing partnership Josef Sattler and Stefan Trautner stand out of the German IDM Sidecar field by using a KTM RC8 R twin as a rocket motor…

 

Sattler, 48 years old and owner of a tuning business in the Bavarian town of Triftern and co-driver Trautner, 29 years old, a welding technician from Julbach in Austria, form the only two-cylinder team in the 2013 IDM sidecar championship. While all their competitors steer machinery with four-cylinder engines the duo uses a RC8 R-Twin from Mattighofen.

Sattler explains the choice of motors: “A year ago while testing at the Slovakia Ring we met the KTM Superbike Team with Martin Bauer and eventually they asked us ‘why don’t you use an RC8 R?’ At the time there were rumours that the Suzuki K7 four, which we then used, would be no longer homologated for the international sidecar events that we also planned to contest. So we checked whether the KTM twin fitted into our chassis and when that was the case, we decided give the project a green light.”

 

Sattler continues: “Actually, the twin fits even better than a four. The swap was done pretty quickly and we are totally satisfied with the performance. The power character of the engine is great and suits us very well; we are enjoying a bit of an advantage with acceleration! Although at the end of very long straights we bite off a bit…then you wish to have 10 to 15hp more.”

The RC8 R-Twin, spiced up with parts from KTM´s Superstock kit, makes 168hp and drives the outfit that weighs 242kg, and, depending on track and gearing, can reach up to 250-270km/h top-speed. The chassis, manufactured by German specialist RSR-sidecars, is made of riveted and bonded aluminium. The brakes and wide tyres (13 and 14 inch) have been taken from Formula 3 racing cars.

With the flexible KTM engine, the usable rev-range is between 4000-10,700rpm. With their former four-cylinder it was far narrower (8000-13,000rpm). During an initial outing at the Lausitzring first comparisons were possible and with the Austrian engine Sattler/Trautner were able to lap one second faster although chassis modifications also contributed to the improvement.

Sattler/Trautner started racing sidecars only three years ago. In their first season in the IDM they rarely saw the chequered flag due to technical problems. The second year they swiftly finished fifth in the championship. For this campaign expectations are higher. Sattler: “We’re really happy with our KTM outfit, so our goal for 2013 is a top-3 ranking. That may sound pretty ambitious, but it should be doable.”