

All suspension joints need to move.

Sometimes in one plane, sometimes in several planes at once, i.e.

an arc.

Rubber is cheap.

It is long lasting, flexible, but ages.

Poly bushes are firmer, flexible, and cheap to manufacture.

Spherical bearings are close tolerance joints, allowing smooth movement about their own axis, i.e.

in more than one plane.

Their weakness is dislike of anything other than smooth surfaces, i.e.

race tracks.

That's why you'll rarely find them on road cars, even modifed cars.

And branded, European motoersport-spec joints are

£60-£80 each.

Obviously Chinese xxxx copy joints are a lot cheaper.

Solid metal would not allow any movement.

No one would
EVER
use a solid metal joint in any part of the suspension system.
