# Formula SAE car: suspension hardpoints and geometry

> Complete suspension hardpoints and kinematic results for the formula sae car example in opensus: camber, caster, roll center, anti-dive, motion ratio and ride frequency.

Pushrod double A-arms, 10 inch wheels and wings. The numbers are representative of this kind of car, not measured from a real one: use them as a starting point and to learn the tool.

## Vehicle

| | |
|---|--:|
| Total mass | 300 kg |
| Wheelbase | 1550 mm |
| Front weight | 46 % |
| CG height | 290 mm |
| Front brake bias | 62 % |

## Results

| Result at the design position | Unit | Front | Rear |
|---|---|--:|--:|
| Suspension type |  | Double A-arm | Double A-arm |
| Static camber | deg | -1.50 | -1.00 |
| Static toe-in | deg | -0.10 | 0.15 |
| Caster | deg | 3.07 | 0.00 |
| Kingpin inclination | deg | 5.57 | 6.63 |
| Scrub radius | mm | 27.6 | 23.9 |
| Mechanical trail | mm | 9.7 | 0.0 |
| Roll center height | mm | 27.5 | 44.8 |
| Track | mm | 1220 | 1196 |
| Anti-dive (front) / anti-lift (rear) in braking | % | 12.6 | 13.5 |
| Anti-lift (front) / anti-squat (rear) under drive | % | 0.0 | -0.2 |
| Motion ratio, spring to wheel |  | 0.674 | 0.655 |
| Spring rate | N/mm | 60 | 65 |
| Wheel rate | N/mm | 27.2 | 27.9 |
| Ride frequency | Hz | 3.11 | 2.88 |

Roll gradient for the whole car: **0.81 deg/g**.

## Front hardpoints (left corner)

Coordinates follow [the opensus conventions](/docs/coordinates/): X forward from the front axle line, Y left from the centreline, Z up from the ground, at the loaded static position.

| Point | Name in links | X mm | Y mm | Z mm |
|---|---|--:|--:|--:|
| Upper arm, front inner | `ucaFront` | 110.0 | 280.0 | 292.0 |
| Upper arm, rear inner | `ucaRear` | -110.0 | 280.0 | 288.0 |
| Upper ball joint | `ucaOuter` | -8.0 | 550.0 | 330.0 |
| Lower arm, front inner | `lcaFront` | 120.0 | 200.0 | 113.0 |
| Lower arm, rear inner | `lcaRear` | -120.0 | 200.0 | 117.0 |
| Lower ball joint | `lcaOuter` | 3.0 | 570.0 | 125.0 |
| Tie rod inner | `tieInner` | -68.0 | 215.0 | 148.0 |
| Tie rod outer | `tieOuter` | -70.0 | 565.0 | 165.0 |
| Wheel centre | `wheelCentre` | 0.0 | 604.0 | 222.4 |
| Pushrod at lower arm | `rodOuter` | 0.0 | 530.0 | 135.0 |
| Pushrod at rocker | `rodInner` | 0.0 | 260.0 | 420.0 |
| Rocker pivot | `rockerPivot` | 0.0 | 220.0 | 370.0 |
| Rocker axis | `rockerAxis` | 40.0 | 220.0 | 370.0 |
| Coilover at rocker | `springRocker` | 0.0 | 170.0 | 410.0 |
| Coilover at chassis | `springChassis` | 0.0 | 60.0 | 300.0 |
| Sway bar pivot | `arbPivot` | 70.0 | 175.0 | 300.0 |
| Sway bar axis | `arbAxis` | 70.0 | 115.0 | 300.0 |
| Sway bar arm tip | `arbTip` | -30.0 | 175.0 | 300.0 |
| Drop link at rocker | `arbDrop` | -30.0 | 175.0 | 395.0 |

## Rear hardpoints (left corner)

X is measured from the rear axle line.

| Point | Name in links | X mm | Y mm | Z mm |
|---|---|--:|--:|--:|
| Upper arm, front inner | `ucaFront` | 110.0 | 270.0 | 294.0 |
| Upper arm, rear inner | `ucaRear` | -110.0 | 270.0 | 302.0 |
| Upper ball joint | `ucaOuter` | 0.0 | 535.0 | 335.0 |
| Lower arm, front inner | `lcaFront` | 130.0 | 190.0 | 124.0 |
| Lower arm, rear inner | `lcaRear` | -130.0 | 190.0 | 116.0 |
| Lower ball joint | `lcaOuter` | 0.0 | 560.0 | 120.0 |
| Toe link inner | `tieInner` | -120.0 | 205.0 | 155.0 |
| Toe link outer | `tieOuter` | -120.0 | 555.0 | 165.0 |
| Wheel centre | `wheelCentre` | 0.0 | 594.0 | 221.4 |
| Pushrod at lower arm | `rodOuter` | 0.0 | 520.0 | 130.0 |
| Pushrod at rocker | `rodInner` | 0.0 | 250.0 | 415.0 |
| Rocker pivot | `rockerPivot` | 0.0 | 210.0 | 365.0 |
| Rocker axis | `rockerAxis` | 40.0 | 210.0 | 365.0 |
| Coilover at rocker | `springRocker` | 0.0 | 160.0 | 405.0 |
| Coilover at chassis | `springChassis` | 0.0 | 55.0 | 295.0 |
| Sway bar pivot | `arbPivot` | -70.0 | 165.0 | 295.0 |
| Sway bar axis | `arbAxis` | -70.0 | 105.0 | 295.0 |
| Sway bar arm tip | `arbTip` | 30.0 | 165.0 | 295.0 |
| Drop link at rocker | `arbDrop` | 30.0 | 165.0 | 390.0 |

These tables are generated from the example built into opensus, so they always match what the tool loads.

[Open in opensus](https://opensus.app/app/?example=fsae)

Source: https://opensus.app/docs/examples/fsae/ (last updated 2026-11-07)