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Bump Stops

Bumpstop Page

Configure corner bump stops and optional heave bump stops. Bump stops are progressive-rate elements that engage when the suspension reaches a defined gap distance, providing increasing resistance to prevent metal-to-metal contact.

Bump stops are optional — they are toggled on or off globally. Heave bump stops are toggled independently per axle as part of the heave system.

Parameters

Reference Component

Each bump stop has a Reference Component selector that determines which motion ratio is used to translate wheel movement into bump stop displacement:

Option Description Motion Ratio Used
Spring Gap is measured relative to spring compression Spring motion ratio from Kinematics
Damper Gap is measured relative to damper travel Damper motion ratio from Kinematics
Wheel Gap is measured relative to vertical wheel travel 1:1 (no motion ratio applied)

The reference component choice affects both the gap measurement and the effective bump stop rate at the wheel. For example, if the bump stop references the spring, the effective wheel rate of the bump stop is:

Bump Stop Wheel Rate = Bump Stop Spring Rate x Spring Motion Ratio²

Spring Rate

The bump stop spring rate defines the force-displacement characteristic when engaged:

Parameter Description Unit
Spring Rate Bump stop stiffness — constant value or 1D map (Distance vs Force) N/m

Supports two data type modes:

  • Value — a single constant stiffness
  • 1D Map — a lookup table of displacement (m) vs force (N) for progressive bump stops

Damping Rate

The bump stop damping rate defines velocity-dependent force when engaged:

Parameter Description Unit
Damping Rate Bump stop damping — constant value or 1D map (Speed vs Force) Ns/m

Supports two data type modes:

  • Value — a single constant damping coefficient
  • 1D Map — a lookup table of velocity (m/s) vs force (N)

Bump Stop Engagement

Bump stops only produce force when they are engaged (displacement beyond the gap distance). The gap distance is configured in the Initialization page under the Gaps section.

Heave Bump Stops

Heave bump stops are optional and part of the heave system. They function identically to corner bump stops but act on the average wheel displacement of the axle.

Heave bump stops have the same parameters (Reference Component, Spring Rate, Damping Rate) and the same data type options as corner bump stops. The heave bump stop gap is configured in Initialization.

Validation Warnings

Condition Warning
Linearized damping > 500 kNs/m Very high bump stop damping