Red Bull KTM riders Tomoyoshi Koyama and Randy Krummenacher have been testing a new chassis on their 125 FRR - and are now even more confident for the German Grand Prix on the meandering and challenging Sachsenring circuit this weekend.
With one victory, one second and one third place for Tomoyoshi Koyama, and with Randy Krummenacher climbing the podium for the first time ever in Barcelona, Team Red Bull KTM 125 are now a force to be reckoned with in this year's world championship. There is much more to come once the 24-year-old Japanese ace and the 17-year-old Swiss GP rookie have all the experience necessary finding the perfect set-up for their nimble 55-horsepower machines.
So far, the team has been walking a fine line. On some occasions, like Koyama's and Krummenacher's double podium in Barcelona, the orange-coloured rockets ran perfectly from start to finish. But on other occasions, riders have struggled with chattering, a strange form of vibration that goes through the entire motorcycle and makes it impossible to open the throttle very early on the corner exits. Often it is the excessive rear wheel that introduces chattering into the chassis. But good rear wheel grip is essential in racing, and no team or rider would want to sacrifice it with a harder tyre compound to solve the problem.
The only way is to work on other components of the bike. Changes in suspension and chassis may shift the frequency of the chatter and may even eliminate it on the race track. That is why Koyama and Krummenacher were onboard a new prototype chassis for two days of testing at Brno last week, aimed at evaluating whether this would improve handling and ride-ability.
But the weather created problems at the circuit in the Czech Republic and recurring rain storms made it difficult for the teams present to enjoy any dry track time. On day one the riders did not start until 1400 hours and before they left the circuit on day two Koyama had been able to put in only ten flying laps with the new chassis. Krummenacher was even unluckier. He only managed to put in one fast lap on the new bike.
Despite these problems, the results were encouraging and lap times came off easily without the riders pushing hard. Koyama clocked his best lap in 2:10.3 minutes, just 0.4 seconds behind the fastest rider on the track. And despite adverse weather, Krummenacher was not far behind, putting in a fastest lap of 2:11.7 minutes. The new chassis, with less rigidity on the swing arm, and alterations in stiffness and rigidity throughout, seemed to absorb vibrations much better than the previous model. It also made it easier to keep tight cornering lines, another problem the KTM 125 cc riders have experienced on occasions.
KTM's engineers are now using a special test bench in the KTM factory's Racing Department at Mattighofen, Austria. With it they can measure and analyse chassis stiffness and chassis torsion when certain forces are introduced. This new method removes a lot of the development process trial and error and leads to quick and encouraging results.
Red Bull KTM Technical Director confirmed however that results had not yet been conclusive.
"Due to the bad weather, we don't have any final confirmation about the qualities of our new prototype chassis. We also haven't been able to accomplish our goal of finding out where and in exactly which situations the new chassis behaves better or differently when compared to the old one," he said. "Therefore, Koyama and Krummenacher will both run two different bikes at the Sachsenring, with an old and a new chassis each, for back-to-back comparisons."
Meanwhile both riders are glowing with confidence for the upcoming German Grand Prix and both have good memories of the Sachsenring. Koyama took one world championship point there after having missed three previous rounds due to injury. And Krummenacher finished 16th just behind Koyama, in only the second Grand Prix of his young career. One year later, both of them are aiming much higher and daring to dream of a repeat of their success in Barcelona at the beginning of June. "I like the Sachsenring, and I have proved that I am fast there," Randy Krummenacher says with a smile. "I hope to be able to go with the front runners again. If we can get the set-up right, some of my rivals will have to brace themselves!"
Related News
