I thought we were done with this topic but it looks like you still want to argue about it.
It's true I did not pay all that much attention at skool...
but as I understand it you do also need to include the duration of the bump in your calculations and you didn't... (although admittedly I know little about it).
If our bump is 2" high and has a duration of 6" then the theoretical (if it was a uniform bump) angle of the bump would have a radius of arctan (2/6) = 0.32 rad, or 18.4 degrees).
Now our car travelling at 50kmh:
Our Horizontal speed over the 5cm bump (as I'm sure you know) is 50 x cos18.4 = 47.44 km/h (It's also 1318cm/sec We'll need this later).
Vertical speed of the wheel over the bump will be 50 x sin18.4 or 15.78 km/h
Now then... The time it takes to travel 6" (or 15cm) at 47.44km/h = (15 / 1318cm) or 0.011s
Our wheel's vertical speed over the bump is 15.78 km/h or 4.38m/s.
Upward acceleration of the wheel is therefore 4.38 / 0.11 or 39.8m/s2 ... which comes out at 4.06g. You can see that a longer duration bump reduces the G loading through the wheel... so your 5g was a pretty good estimate.
Anyhoo.. if the unsprung weight of the wheel, tyre, hub and brake caliper etc. weighs in even at a portly 25 kilos then (ignoring any dissipation of force by the tyre).. hitting that ^ 5cm bump at 31mph (50km/h in the old money) means it would exert a force of 995Nm (or Kg/m2).
I still can't see why that would be a problem for a bolt with a shear-limit of circa 5 tonnes, even if we add half of 60% of the weight of the car (I offered a generous 600kg) to it.
I don't know enough about it to work out the force through the suspension if the wheel hit a 10cm deep pothole at 100km/h... (and I though UK roads were bad..
) but;
a) I doubt it would be as much as hitting the 5cm bump at the same speed, since the suspension is in extension, not compression. The wheel speed (G) is reduced to the force exerted by the springs.
b) Hitting the edge of the pothole (coming out of it) might be a different story
c) If I dropped an 11" radius wheel (7.5" plus 3.5" of sidewall) into a 4" deep pot-hole at 100km/h, then suspension bolts is not going to be the biggest problem..
Ralf S.