A while back, I bought some aftermarket rims for my '15 Golf to replace the sad 15" 195-section tires that came stock, and got 17 Sparco Pro Corsa rims with BF Goodrich gforce comp-2 all seasons.
It drove great for a few weeks, (beautifully, even). Then I hit the mother of all potholes. My stomach sank the moment I ran over this product of poor infrastructure management. Little did I know I would be cursing this moment for months to come.
The next day was when the vibration started. At this point, it started at 50 mph or so, and just got worse on the highway. I had to get 2 new rims on the right side, and the people at AAA said it was fine.
It wasn’t fine. Really, it wasn’t any better. So I took it back, and advised that I replace the two tires, because it was highly likely they had slipped belts from the impact. A couple more hundred dollars later, it was… a little better. But it wasn’t back to normal. By this point I was done with AAA, and went to the dealer. They noticed that one of the spacers was installed crooked. Great. They fixed that, and didn’t notice anything wrong until the next time I went on the interstate, when I noticed that, indeed, it still was vibrating. This time, however, it was just above 65 mph.
This is where I should describe the vibration in greater detail. From 0 to 65, nothing is wrong. But as soon as I hit 65, the steering wheel shimmys and the car whole car lightly shakes. It goes in and out, like it is being occasionally canceled out, and is not throtttle, braking, or turning sensitive.
Back to the dealer it was, and of course, they could not find the root of my frustration. They did put the stock wheels on, and the vibration stopped. With the aftermarket ones, it still did vibrate, even with a rotation, balancing, allignment, et cetera.
So, the question is: what the heck is going on? How can this be A) diagnosed and B) fixed without getting new wheels/tires or renting a chassis dyno?
As someone who both loves driving and has a pet peeve for this sort of thing, any advice you could give would be most appreciated.