Shock Absorber Forces

[jam_rs]

Shock Absorber Forces

Too much shock: overall
■ A very sudden car with harsh ride qualities, much sliding and wheel patter
■ Car will not absorb road surface irregularities but crashes over them

Too much rebound force
■ Wheels do not return quickly to road surface after displacement. Inside wheel in a corner may be pulled off the road by the damper while still loaded
■ Car may "jack down" over bumps or in long corners causing a loss of tyre compliance. Car does not power down well at exit of corners when road surface is not extremely smooth

Too much bump force: general
■ Harsh reaction to road surface irregularities.
■ Car slides rather than sticking
■ Car doesn't put power down well - driving wheels hop.

Too much low piston speed bump force
■ Car's reaction to steering input too sudden
■ Car's reaction to lateral and longitudinal load transfer too harsh

Too much high piston speed bump force
■ Car's reaction to minor road surface irregularities too harsh - tyres hop over "chatter bumps" and ripples in braking areas and corner exits.

Too little shock: overall
■ Car floats a lot (the Cadillac ride syndrome) and oscillates after bumps
■ Car dives and squats a lot
■ Car rolls quickly in response to lateral acceleration and may tend to "fall over" onto the outside front tyre during corner entry and outside rear tyre on corner exit.
■ Car is generally sloppy and unresponsive

Too little rebound force: overall
■ Car floats - oscillates after bumps (the Cadillac ride syndrome)

Too little bump force: overall
■ Initial turn in reaction soft and sloppy
■ Excessive and quick roll, dive and squat

Too little low piston speed bump force
■ Car is generally imprecise and sloppy in response to lateral (and, to a lesser extent longitudinal) accelerations and to driver steering inputs

Too little high piston speed bump force
■ Suspension may bottom over the largest bumps on the track resulting in momentary loss of tyre contact and excessive instantaneous loads on suspension and chassis

Dead shock on one corner
■ A dead shock is surprisingly difficult for a driver to identify and/or isolate
- At the rear, the car will "fall over" onto the outside tyre and oversteer in one direction only
- At the front, the car will "fall over" onto the outside tyre on corner entry and then understeer.