<VV> Springs

[Hugo Miller]

While I'm on a roll, I might enquire why my rear springs have some sort 
of clamps around them. They look a bit like exhaust hanger dougnhnuts, 
but cut open to hook over the spring coils, and they seem to be a very 
hard plastic material. I have two on each rear spring. I can't figure 
out whether their function is as rebound stops (by stopping the spring 
expanding too much) or bump stops (by acting as buffers between the 
coils). It does look a bit low at the back (or maybe high at the 
front?). I've never seen anything like this before.