Speed&Power Cadence SteeringGeometry SpokeLength PedalKickBack Suspension Links

Influence of Pedal Force on rear wheel suspension ( pogo effect )
Pedal Kick Back over 20 mm suspension-travel

Application not available, because your Browser does not support Java, or Java has been disabled.

Comma or point may be used as decimal point. All coordinates in millimeters.
Simply drag the lightgrey-filled bicycle components around and watch the diagram bars.
To ease measurements, even the horizontal scale of the x-axis is draggable.
Influence of pedal-force on rear wheel suspension ( pogo effect ):
Positive values: The suspension (rear section of the bicycle) is lifted up. The above, left diagram bar displays the crucial coefficient of this influence, i. e. how big, related to the pedal force, the force will be which tries to lift (or lower) the rear section of the bicycle. To get the real amount of that lifting (lowering) force, simply multiply the displayed value by pedal-force (example: diagram value = 5 %, pedal-force = 400 N => rear section of bicycle is lifted up with 20 N).
The influence on the suspension consists of the following components:

Chain tension generates a torque upon the swingarm if pedal kick back is present (different from zero).
Squat: Acceleration force and air-resistance force cause the wheel-load distribution be shifted towards the rear wheel (as long as a driving force is taking effect). Note that the program assumes both the gravity and aerodynamic center to be at the same spot - this simplification should match the reality fairly well.
Vertical force at swingarm pivot, induced by reaction force of driving force If the swingarm is not exactly horizontal, the reaction force of the driving force generates a vertical force vector at the swingarm pivot. (See picture.)
The gear-ratio inside a gear hub generates a torque upon the hub axle. This torque is transmitted to the swingarm.

Pedal Kick Back:
Positive values: the chain is pulling the pedals backward. More precisely: Over the time span the rear wheel needs to travel 20 mm upward (projected to the vertical), the pedal-stroke arc of the forward-spinning cranks is shortened by the displayed amount.
Gear hub or derailleur system?
For derailleur system: Set the Gear-Ratio slider to 1.0 (= no gear inside hub).
Center of Gravity:
Approximately located at the rider's umbilicus.
Transmission with/without chain idler?
To explore a transmission without deflection of the forward-chain, simply drag the idler far enough upward... This way even the properties of an upleft... bicycle can be simulated.
Multi-link swingarm designs?
The results are only valid for mono-link designs.

TopOfPage | PedalKickBackCalculator

Speed&Power Cadence SteeringGeometry SpokeLength PedalKickBack Suspension Links


Copyright © Impressum / About this page
Last modified: 12. 5. 2008

  GOWEBCounter by INLINE