They screwed up my rims!!!

[Hethj7]

Originally Posted by HoodStrype

That's interesting... 60-65 huh? I'll have to bring that up and play "I know more than you do" to them... I haven't even been back. I just now got the car off jackstands... putting in stock coil springs sux! I'll give him a happy holiday visit friday (along with everyone else). The rims were bought brand new so they were not weighted- I'll have to be a smart a$$ and tell him I do not like "dynamic" weighting

Thanks for the info!

Dude, there is quite a bit that goes into when a wheel will vibrate. I'm not going to go dig up my old dynamic controls book, but off the top of my head, the RPM of the wheel at which you'll get vibration would be the critical frequency. If you picture an amplitude vs. frequency graph, the critical frequency is essentially the frequency at which the amplitude tries to go to infiniti. I believe that the mass of the wheel and also it's diameter would affect where this occurs. So, to say that all cars vibrate at xx mph would be wrong. Adding wheel weights to a car helps to dampen the amplitude (vibration) of the wheel and would serve to either push the critical frequency to a speed (rpm) beyond what you normally see or to help get though the critical frequency faster if it occurs at slower speeds.

Have you ever had a vibraton in a car that happens at say 70 mph, but goes away at 80? This is because the rpm of your wheels has passed through the critical frequency and no longer want to vibrate as much (the amplitude of their response is not as great). I doubt this guy knows what he's talking about and should have just put the weights inside the rim to begin with.