Hey, I've hardly ever posted on here, but this problem has currently me and the other half stumped.

The car is a 2000 1.7 Puma, if that has any significance on the problem (don't think it does really)

Symptoms:
Getting a 'thunk-thunk-thunk' coming from what I'm 90% sure is the n/s front wheel area.
It's always relative to the wheel speed. (i.e. sounds like there's something stuck in the tyre thread)
Most noticeable between 10-25 mph.
Seems to go over 30 mph unless I really listen for it, then is extremely faint.
Can feel the noise as much as hear it through the car.
Slightly louder on bends to the right than it is on bends to the left.
Very slight new vibration of the steering wheel at higher (motorway) speeds, (might not be related - I'm hyper-sensitive to steering wheel wobbles and vibrations)

Causes ruled out: (i.e. noise present both before and after)
Wheel bearing (changed at the weekend)
Wheel and/or tyre issues (changed for spare last night)
Brake caliper is not loose.

We're going to systematically check everything that we can that's related to the movement of the wheel during the course of the week and over the weekend, but any suggestions or ideally an "I know what that is!" will be very helpful! Usually we can work out what any problems are between us, but this is just not something that we've ever come across before!

Our next point to check is the brake pads and discs for any warping.