Rider's Manual K 1200 S - K100.biz

680Engineering detailszBrake system withBMW Motorrad IntegralABSPartially integral brakesYour motorcycle is equipped withpartially integral brakes. Bothfront and rear brakes are appliedwhen you pull the handbrakelever. The footbrake lever actsonly on the rear brake.While the brakes are slowing themotorcycle, the BMW MotorradIntegral ABS adapts braking-forcedistribution between front andrear brakes to suit the load onthe motorcycle.The integral braking functionmakes it very difficultto spin the rear wheel by openingthe throttle with the front brakeapplied to keep the motorcyclestationary (burn-out). Attemptedburn-outs can result in damageto the rear brake and the clutch.Do not attempt burn-outs.How does ABS work?The amount of braking force thatcan be transferred to the roaddepends on factors hat includethe coefficient of friction of theroad surface. Loose stones, iceand snow or a wet road all havemuch lower coefficients of frictionthan a clean, dry asphalt surface.The lower the coefficientof friction, the longer the brakingdistance.If the rider increases brakingpressure to the extent that brakingforce exceeds the maximumtransferrable limit, the wheelsstart to lock and the motorcycleloses its directional stability; a fallis imminent. Before this situationcan occur, ABS intervenes andadapts braking pressure to themaximum transferrable brakingforce, so the wheels continueto turn and directional stabilityis maintained irrespective of thecondition of the road surface.What are the effects ofsurface irregularities?Humps and surface irregularitiescan cause the wheels tolose contact temporarily with theroad surface; if this happens thebraking force that can be transmittedto the road can drop tozero. If the brakes are appliedunder these circumstances theABS has to reduce braking forceto ensure that directional stabilityis maintained when thewheels regain contact with theroad surface. At this instant theBMW Motorrad Integral ABSmust assume an extremely lowcoefficient of friction, so that thewheels will continue to rotate underall imaginable circumstances,because this is the preconditionfor ensuring directional stability.As soon as is registers the actualcircumstances, the systemreacts instantly and adjusts brak-