thanks for the info. This is a brand new build so it could be something that i've done. Could chassie/bulk head allignment cause this? Although everything looks spot on.
It is a 2nd hand set of tires though so could be that. It's been years since i raced (mi2ec)!

I'll check for ballooning in the tires. I know this was a common issue with 1/8 Nitro. when the foams broke down the tires would cause vibrations.

thanks