Dashed lines show UCA/LCA arm angles extended to the side-view instant centre (SVIC). The solid line from contact patch through SVIC defines the anti-geometry angle θ.
To reduce bump steer:
↑ Raise inner pivot Z to match LCA arc
↓ Lower outer pivot Z if toe-in on bump
Match tie rod length to LCA effective length
Ideal: outer pivot on same arc as wheel hub
Target: < 0.05° per 10 mm
Flat = no bump steer. S-curve = tie rod too short/long. Target: ±0.05° across full travel.
Amber = tie rod. Move inner pivot vertically to match the LCA arc (green).
Current spring rate marked. Shaded bands: blue = road target, green = circuit, amber = F1/formula.
Static — ride height
Full bump
Full droop
Target: 0.5–1.5° gain per 25 mm bump for motorsport.
Low migration = consistent handling balance.
Keep under ±4 mm for low tyre wear.
Target < 0.05° per 10 mm for circuit use.