4-Link Suspension Geometry Calculator - Static vs Bump, Anti-Squat & Roll Center

This document is a screenshot of a suspension link geometry calculator spreadsheet, apparently used for designing a 4-link suspension. It compares 'Static Geometry' and 'Bump Geometry' (at 7.00 in of travel, with a stated pinion angle change of 2.59 degrees). For both upper and lower links it lists frame-end and axle-end x/y/z coordinates, link vectors, link lengths (31.611 in upper, 38.000 in lower static / 38.328 in in bump), unit vectors, intercepts, roll points, vertical and horizontal slopes, and calculated link forces (6821 lb static, 9089 lb in bump for the upper links). Geometry summaries give anti-squat (55.877% static vs 34.651% in bump), roll axis slope (-0.0088 vs -0.2052 in/in, both noted as Roll Understeer), roll center height (29.313 in vs 36.732 in), roll axis angle (-0.504 vs -11.594 degrees), and instant center X-axis (231.667 vs 116.473 in) and Z-axis (53.167 vs 21.054 in) locations. A graphical side/top-view plot on the right shows the link layout with red and blue links, a tire circle, and roll axis lines, with a 'Bump' button beneath. A reader can learn the exact link mounting coordinates and how the suspension's anti-squat, roll center, and instant center change through bump travel.