My 2001 estate1.8 tddi has recently developed a sort of hum/drone noise which seems to come from the front and not engine related. It is noticeable from about 50mph to about 65mph..When driving slow its not there or at least not audible.

If driving over a humpy road as the car bobs up and down the noise cuts out and in with the up and down movement and also it cuts out when the steering wheel is turned to the right even ever so slightly to the right. Like going round a right hand bend its not there but when straightening out again it comes in again. Also I feel a slight vibration with it through the floor.

The only thing done recently to the car was a new dropbar (anti roll bar) link was put on the front passenger side.

Sounds like a shot wheel bearing to me bud.

Think if you jack the car up and try move the wheel from side to side there shouldn't be any play in it all. You may also be able to hear the drone by spinning the wheel. If there is any play/noise, a new bearing should sort it.

Not sure on the Focus if you can just replace the bearing or if the hub needs replaced, but it should give you a starting point to look into.

Sounds like a bearing to me too.

On the mk1 the bearing can be replaced using the old hub, unlike the mk2 where it uses a bearing/hub assembly and a bit of skill or the correct tools to fit. It will still require the use of a press though.