Carry wheel load from the front upper A-arm into the front bellcrank.
A pull rod rather than a push rod: the wheel moving up pulls the rod, which rotates the bellcrank. Pull rod actuation lets the bellcrank and damper sit low in the chassis, which lowers CG.
Sized for axial load and buckling. Front pullrod tubes could not be made in carbon on CR26I because of packaging constraints, so this one component stayed steel while the tie rods and pushrod moved to CFRP.
Deflection under cornering: 1516.984 lb load over 9.313 in gives 0.00431 in extension. Maximum load seen at the rod end 1517 lb against a 5262 lb static radial load rating for the 1/4 in bore FK JMX rod end, FoS 3.469.
AISI 4130 steel tube with threaded inserts and FK alloy steel rod ends. From the cost report drawings and CAD: From the cost report drawings: AISI 4130 Alloy Steel (CR25_Pullrod_Tube).
Shakedown 7-15-23 logged the front left inner jam nut as completely loose, and the pullrod outer bolts as among several fasteners found without torque seal. Torque seal on every suspension fastener is now part of the drive prep checklist.
Tube 0.875 in x 1.125 in, 10.06 in long, 2 in rod insert length, design FoS 2. From the cost report drawings and CAD: Measured mass: 422.5 g average across 2 weighed instances (FL Pullrod 423.0 g, FR Pullrod 422.0 g), uncertainty +- 1 g. Left-to-right deviation 0.24%. Weighed mass: 423.0 g (0.933 lb) (recorded as: FL Pullrod). Weighed mass: 422.0 g (0.930 lb) (recorded as: FR Pullrod). Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. CR25_Pullrod_Tube (as drawn): 15.88, 1.59, 12.70, 1.27, 236.54, 23.65 Source: CR22 Suspension Component Weights.xlsx (weighed, not CAD) | Subteam weight books: CR22/Suspension/Validation/Full System Analysis/Component Weights.xlsx | Cost report drawings: CR25/Suspension/Management-Comp/Cost Report/Drawings/Sus Shocks - Front Indirect Actuation Assembly/CR25_Pullrod_Tube.pdf Quantity per car, as costed: 2
Nothing in CrimsonStorage covers these yet.