2000 NB shaking vigorously at freeway speed (I dont think its the 65 mph shimmy)

[Jeremiah]

Whats up guys, my 2000 Miata LS (NB) recently started shaking/vibrating at freeway speeds (65+ mph). This all started yesterday after a car cut me off forcing me to slam the brakes (couldnt just left off the throttle, car was way to close). Well shortly after the car would vibrate at speed. When I got home inspect the tires and the passenger side front looked to have a bald spot about the size of my palm. I thought maybe the bald spot was making the car run all squagly at speed and even changed the tire (it was low on tread anyways) to no avail. Then my mechanic today spots my driver side rear tire with a bald spot (was getting new break pads installed/rotors resurfaced). I dont want to change that tire too because it might not even be the issue. Maybe my hardtop is not secured but I checked it and its bolted down. Any ideas guys? This really sucks.

[— kung fu jesus —]

Flatspotted tires do things just like that.

[Mountain Green]

My first experience with Miata severe vibrations, was last week driving it home after initial purchase.
All was fine till I hit the highway, then severe car vibration, but not in the steering wheel.
Problem was, left rear tire was down to 10 PSI, while all others were > 26 . Fixed the air pressures, and
no more vibrations. Just offering a simple check to fix.

[Jeremiah]

Thanks for the input guys, my mechanic confirmed as you guys said as well. Flat spotted tires due to locking the brakes. :O

[— kung fu jesus —]

Yeah, that is some severe flatspotting.

[maharaj]

I'd recommend countless burnouts now to get your money's worth out of those tires!

[—RuckkehrMiata—]

Egh! My friend flatspotted while in the mountains around the LA basin's north range one night. I didn't notice a change at the time, but he fretted and freaked out all the way back to his apartment saying he could feel it. Once we got on the highway I felt it ._.

Luckily his wasn't very bad, and seemed to kink itself out after a week or two.

[Jeremiah]

Yeah, that is some severe flatspotting.

I'd recommend countless burnouts now to get your money's worth out of those tires!

Egh! My friend flatspotted while in the mountains around the LA basin's north range one night. I didn't notice a change at the time, but he fretted and freaked out all the way back to his apartment saying he could feel it. Once we got on the highway I felt it ._.

Luckily his wasn't very bad, and seemed to kink itself out after a week or two.

1. Yeah it is.

2. I would love to do some spirited driving but I have one new tire on the car (was put on today because one of my tires was bad) and I am going back in tommorow to return it. Its a 205/50/15 falken ziex 512 tire. Im going back to 195/50/15 and getting some Kumho Ectsa tires.

3. Yeah on the surface streets (45 mph and below is fine) but at freeway speed...the car is wobbly.