urethane or rubber for shockie bushes

[dinos4x4]

I have a 100 series cruiser (solid axel)

One of the rubber bushes on my Koni shocks has flogged out

I talked to Pedders i they are trying to get me to buy some urethane bushes, they seam to stiff to me with no give.

what do u fellas reckon

[HotFourOk]

The less give the better I say.. the shock should stay put!

The rubber has flogged out for a reason.. so the urethane may last longer

[chimpboy]

The reason you need give, it seems to me, is that the shock changes angle slightly as the axle moves up and down. So I think there's a definite limit to the whole "the less give the better" concept - if the bush is too rigid, then you are going to have some metal trying to flex when it's not designed to.

This doesn't answer your question though I guess, I don't know if urethane seems really stiff to the human hand but actually flexes enough when it's part of the suspension of a very heavy vehicle. They still ship all new shocks with rubber though, don't they?

[HotFourOk]

I'm pretty sure most shocks come with rubber bushes...(The eye mount ones anyway).. Urethane is normally used by people to upgrade the buhses - Eg better handling etc

I just found this also...

The most common mistake that people make when fitting and using urethane bushes is that they are compared to rubber bushes.
Polyurethane works in a completely different manner to rubber bushes, in that urethane slides on the surfaces of the pin/shackle and therefore requires the surfaces to be clean and smooth, and well lubricated.

[chimpboy]

I definitely see scope for using urethane to upgrade bushes in other areas. I'm not convinced it's a great mod for shock mounts though. My mind is open on this one, personally; I find it hard to believe that rubber shock bushes are actually having any effect on handling though, I gotta say. Shocks do one thing: they stop the spring from re-bouncing. They don't actually hold the wheels in any particular position the way other suspension components do.

[HotFourOk]

Good point there Chimpboy... Not like a swaybar bush or similar, that resists against the suspension components