Broken rear suspension spring?

[Rob Bell]

I've spotted something odd about our ZTT - it seems to be sitting a bit lower on the rear nearside than it is on the offside rear.

It has one finger clearance on the nearside between the tyre and the wheel arch above, whereas on the offside it's two finger clearance.

I have a nasty feeling that the spring has fractured.

How common is this problem? I need to take the wheel off when I get a chance - is the fracture usually obvious - and how much work is it to replace?

Thanks chaps!