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Discussion Starter · #1 ·
The bilstein shock has a groove milled into the body of the shock which receives a snap-ring type piece of metal. The snap ring seems to be the only thing keeping the threaded sleeve from sliding when pressure (ie; the weight of the car) is applied. To me, it looks like 1/4 the wieght of the enitre vehicle is transferred through that 1/16" snap ring, seems like alot! Is this how all coil over shocks are designed? The spindle has 2 giant "10.9" bolts tying it to the upper control arm, why such huge bolts when all that weight is going through the snap ring?
 

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FFCobra Fanatic
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378 Posts
One corner of the car weighs about 500 pounds. Multiply that by 10 G's for a factor of safety and you get a 5000 pound load. The wire you say is 1/16th diameter (seems pretty small to me) and I'll guess the shock is 1 5/8 OD. The circumference is 1 5/8 times PI, which equals 5.1 inches. 5.1 inches times 1/16 inches = .319 square inches. That's the area of metal you have to shear for it to fail. So take 5000 LB and divide by .318 square inches and that gives you 15,700 pounds per square inch. Even crap steel has a yield strength above that. Isn't math fun!

Actually, round rings are better than a thread in fatigue. Threads have a sharper radius in the root and are bigger stress risers. The ring does a great job at smoothly distributing the load.

The front strut bolts are not a fair comparison. They were designed to hold the spindle vertical when the tire smacks something on the side, say a curb. The bolts are closely spaced (short coupled) and I can see it being a tremendous load. It's kind of like the load it would take to tighten a lug nut with a 2 inch long torque wrench.
 
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