TYRE IRREGULARITIES AND THEIR EFFECTS IN VEHICLE WHEEL TYRES

REIFENUNGLEICHFOERMIGKEIT UND DEREN AUSWIRKUNGEN BEI KRAFTRADREIFEN

FROM TRIAL RUNS IT WAS ESTABLISHED THAT FREQUENTLY THERE WERE STRIKINGLY DIFFERENT RIDING QUALITIES FROM EXTERNALLY SIMILAR TYRES AND THESE SHOWED THEMSELVES BY UNSTEADY STEERING ON UNEVEN ROADS (MOSTLY AT HIGHER SPEEDS) AND BY STEERING FLUTTER ON EVEN ROAD SURFACES OVER A SPECIFIC SPEED RANGE, NOT USUALLY HIGH, WHICH WAS NORMALLY DISTURBING ALTHOUGH NOT DANGEROUS. THE FORCES WERE MEASURED NOT DURING THE STATIONARY PERIOD OF ROLLERS OF THE TEST RIG BUT DURING THE MOVEMENT OF THE WHEEL. THE FOLLOWING FORCES WERE MEASURED: SIDE FORCES, MOMENTS OF WHEEL CONTACT POINT AND RADIAL FORCES. FROM THE MEASURED VALUES THE FOLLOWING CONCLUSIONS WERE DERIVED: THE RADIAL FORCE FLUCTUATIONS SHOWED NO CORRELATION WITH THE SUBJECTIVE RIDING CHARACTERISTICS. A NOTICEABLE CONNECTION APPEARED BETWEEN THE SIDE FORCES AND THE MOMENT FLUCTUATION AND WITH THE RIDING QUALITIES. IN MOST CASES TYRES WITH HIGH SIDE FORCE FLUCTUATIONS ALSO SHOWED HIGH MOMENT FLUCTUATIONS. THE TRIALS INDICATE THAT TO EXCEED A SPECIFIC LIMIT OF MEASUREMENT IS SUFFICIENT TO PRODUCE BAD RIDING CHARACTERISTICS. FROM THE TYRES ALREADY TESTED IT IS POSSIBLE TO DERIVE APPROXIMATE LIMITS, WHICH ARE ILLUSTRATED IN TABLES. WITH VEHICLE WHEELS SUSCEPTIBLE TO ACTING IN AN OSCILLATORY MANNER RELATIVELY SMALL TYRE FLUCTUATIONS LEAD TO FLUTTER CONDITIONS WHICH CAN INFLUENCE THE SAFETY OF TRAFFIC. AGAINST THAT IT WAS ESTABLISHED THAT WITH CARS HAVING HEAVY DAMPING IN THE STEERING SYSTEM ONLY VERY NOTICEABLE IRREGULARITIES IN THE TYRES LEAD TO A MARKED DECLINE IN RIDING COMFORT AND IN RIDING QUALITIES.

Language

  • German

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Filing Info

  • Accession Number: 01300467
  • Record Type: Publication
  • Source Agency: Bundesanstalt für Straßenwesen (BASt)
  • Files: ITRD
  • Created Date: Nov 21 2010 7:51AM