The front passenger side tire starts to shake at around 60. I've had my suspension and brakes looked and fixed what needed to be fixed, so there's nothing wrong there. What can cause it?
Check your front axles and drive shaft maybe that can cause the vibration i also had the same problem when at 60km and 100km. When i press the gas pedal it starts to vibrated.
Usually at that speed it would be a tire problem. The tire, the wheel or the balance. Swap that right front with the left rear and see if the problem moves with the tire.