Radius Arms turn torsion bar!!

I'm not 100% sure, but I don't think I'm far off here.....

The amount of flex and the resistance in a PU radius arm to axle bush concerns me, and I'm looking at stock concentric not castor correct (which look even worse)

They look like ultimately, they'd flex less, while giving substantially more resistance compared to the stock bushes with the "cut outs" top and bottom which have to be aligned.

Combine this with greater suspension travel and you should be aiming for more articulation from your radius arm bushes, but I think PU bushes will actually give you much less.

I worried as the 2 combinations stack up, all this extra force and torsion has to go somewhere and I suspect it will result in twisting of the radius arm (below the yield so it will just twist back) and/or slotting of the weakest hole (probably the radius arm to chassis). This could result in a very unstable Jimny. (it may even twist the radius arm beyond the yield resulting in permanent deformation!)

I just want to put it out there, I'm looking at the Solid Mechanics behind this not just a suck it and see approach. I know issues have been reported of wobble and slotted holes, and this is my 2 penneth, I think others have voiced similar concerns here and there?

There are quite a number of people that run Poly Urethane Bushes and have for some time without suffering any consequences. I am one of them.

They do flex well and when new, the rubber bushes are quite stiff too.

I can understand your fears but think they are not warranted.

Kirkynut

I totally agree. The standard bushes allow a lot of movement up and down- the plane in which the bushes need to have most movements to allow the axle to flex. The PU bush makers seem to have taken the approach of 'there's a hole, lets fill it' and replaced a very well designed bush with a solid lump of stiffer material. I really don't see how it could be an improvement in any way.

From what I've seen, there are very few suspension modifications that actually increase the flex on a jimny over standard. It seems most people just want lift and don't care about articulation.

I've always used standard bushes, but I do have some 'bits4vits' ones sat at work to go in some new Jimnybits 4" front radius arms....

Gary

Busta wrote: I totally agree. The standard bushes allow a lot of movement up and down- the plane in which the bushes need to have most movements to allow the axle to flex. The PU bush makers seem to have taken the approach of 'there's a hole, lets fill it' and replaced a very well designed bush with a solid lump of stiffer material. I really don't see how it could be an improvement in any way.

From what I've seen, there are very few suspension modifications that actually increase the flex on a jimny over standard. It seems most people just want lift and don't care about articulation.

Have you tried poly bushes? They flex just as much as rubber, therefore give just as much articulation. They make the car feel much better on the road though. So they are a win win solution. The fact that they are easier to change adds to it.

I have not lost any articulation from poly bushes.

Kirkynut