What causes that "ticking" noise from vehicle wheels?

Factual Questions
1

I ride my bike a lot on the roads, so I’m quite accustomed to the noises made by vehicles. Quite often I’ll hear a particular kind of noise coming from the wheels of cars and other vehicles. I can best describe it as a sort of ticking noise, but a bit heavier, almost like a quick slapping sound. The speed of it suggests that it’s happening once per wheel revolution.

Only a few vehicles make this noise, so I assume it’s not something that’s supposed to happen, but what causes it? Is it anything serious? A few possibilities I can think of are a stone stuck in the tyre, a rubbing brake or a dodgy wheel bearing. Any mechanics know the sound I mean?

2

Probably a stone in the tyre for a ticking noise. Possibly something stuck to it for a slapping noise. Wheel bearings tend to make squeak type noises (in my experience which is not extensive).

3

It often means the CV joint needs to be replaced. This happened to my Acura.

4

Or, they left their winter tires on, and what you are hearing are the studs.

5

I can rule that one out as I’m in England - we don’t do winter tyres here. (On the rare occasions we get an inch or two of snow, we prefer simply to descend into chaos and moan about it.)

6

I hear it in my own car whenever there’s a pebble stuck in the tire tread.