1. The problem statement, all variables and given/known data So I am designing the suspension for a small formula car. It's a pushrod suspension much like what is shown below: [PLAIN]http://f1-dictionary.110mb.com/Images/pullrod_poshrod_push.gif [Broken] I am trying to find the required tubing diameter for the loads the car will experience. 2. Relevant equations Ʃf(x)=0 Ʃf(y)=0 σ=F/A 3. The attempt at a solution The free body diagram The car is assumed to weigh 700lbs, have 60-40 front to rear weight distribution and be in a 2G turn, so the maximum force of the tire is 525lb. θ is assued to be 45° By the method of joints: At pinned joint A Ʃf(x)=0=FLCA-cos(θ)Fp Ʃf(y)=0=Ft-Fpsin(θ) At pinned joint B Ʃf(x)=0=-Fs-Fpcos(θ) Ʃf(y)=0=-FRy-Fpsin(θ) So Fp=Ft/sin(θ) And the maximum force in the pushrod is around 743lb. One of the tubing thicknesses under consideration is 5/8 .035 4130 chromoly which has a yield strength of 70PSI. Cross sectional area is ∏/4(.625in-.59in)=.0275 in2 Calculating the stress at maximum load is calculated at around 27000 PSI I know my statics is rusty but this is wayyyyy off. This tubing thickness is within the range of what other people are using, maybe a bit on the small side. Can anyone point out where I may have gone wrong?