MoToRcyclE RoAD SAFETy REpoRT 2010 - Dekra

As far as defects in the assemblies areconcerned (Figure 17), technical lightingequipment heads the list of defectsat more than 30%. In almost one in fivemotorcycles with defects the assemblyconsisting of axles/wheels/tyres/suspensionswere found to be at fault, followedby chassis/frames at 16% and brakes at12%. Of the 30 components most commonlycriticised by DEKRA during themain inspection, tyres, drive chains, brakepads and rear retro-reflectors have thegreatest impact. These components belongto the wheels/tyres, drive train, brakeand lights assemblies. In the wheels/tyresassembly (Figure 19), at just under 25%worn tyres dominated and, for just under12% of motorcycles with defects, the treaddepth was at the wear limit. At around10%, aged tyres account for a relativelyhigh proportion of defects.As regards the drive train (Figure18), in more than 68% of cases the drivechain was to blame. In 30% of cases thetension of the drive chain was too low,and in 17% of cases the drive chain wasworn. Both defects represent a highsafety risk, the reason being that toolow tension can cause the chain to dropoff and to become entangled in the rearwheel, thereby blocking the wheel. If thedrive chain is worn, it may break, withsimilar effects as with too low tension. Inthe brake assembly (Figure 20), at morethan 25% the brake pads have the highestproportion of defects, followed by thehand brake lever with 13% of defects. Asregards the technical lighting equipment(Figure 21), the rear reflector was cruisedthe most, with more than 19% of defects.Also of interest is the issue of tuning,where thoughts generally turn im-18 0The fi ve most frequently criticiseddrive train componentsPercentage of total302010068.7Drive chain19.0Chain wheelDrive pinion5.54.21Chain guardChain tensionerSource: DEKRA 2008. Data from Germany19The most frequent tyre defectsPercentage of total3025201510524.9Tyres worn11.8Tread depthat wear limit10.4 9.6AgedOzone cracksSource: DEKRA 2008. Data from Germany6.0 5.1 4.4 4.0 3.2Filling pressuretoo lowCrackedManufacturer/typenot admissiblePorousSize not admissibleMake/type deviatesfrom part certificate/operating licenserecommendation2.0 1.4 1.3 1.0 0.5 0.5Not registeredRunning direction/assembly faultIrregular wear patternDamagedWorn on one side20The most frequently criticised brake componentsPercentage of total30252015105025.613.3Brake liningwornHand brake lever9.8Brake fluidBrake discSource: DEKRA 2008. Data from Germany8.3 8.3Brake light switch5.7Braking actionBrake pedal4.8 4.7 3.8 3.4Brake hoseBrake pipeBrake lever2.0Brake calliper20 | 21