[monley]

Jezza86 wrote:

what you actually need to get flex from this set-up front arms that have lower controll of the castor angle, via larger, softer bushes, or lower arms that only attach to one mount, and a third upper arm to controll the castor.

cannot remember what thats called.. 1+1+1 link? something like that

A 3-link...

[royce]

Steve (not the opinion squad) is there any relation to suspension behavioir and where in relation to the axle the bushes are? Ie if they were more 12 and 6 o'clock rather than 3 and 9?

I remember seeing an arm like this once but the main part of it went to the bottom bush on the diff and an extra arm bolted to the top diff bush and then to the main arm via another bush, it would be a way too add more compliance into the system.

Probably easier to just make a decent setup though.

[Paulw]

Quote:

Would you get better movement by having a pin at the end instead?

I was going to ask the same thing about the pin type mount, I was thinking that it allows the arm to rotate when articulating?

[SierraDan]

royce wrote:

Arm description

A jeep Y arm?

[Jezza86]

Paul I was thinkin about this but came up withis analogy.
Grab a broom with both hands. Hold it infront of you. Hold it tight in your grip, lower one end of the broom, raise the other. The tension on your wrists and fingers exceeds the tension on your shoulders.

Royce. Dis one ?

[atari4x4]

sounds like the superior superflex arms or what ever they're called & i'm sure we've had this discussion before.


don't know if they actually work as most pics online are of patrols reversed up a ramp.

Paulw wrote:

Quote:

Would you get better movement by having a pin at the end instead?

I was going to ask the same thing about the pin type mount, I was thinking that it allows the arm to rotate when articulating?

range rovers & defenders use a pin mount & seem to be one of the only radius arm set ups that flex, but i think that has something to do with the bush locations on the diff end.

[BertZook]

this is the theory behind the superfelx arms

[SierraDan]

Patrols have a pin.

Super flex arms gave more up travel and body roll according to several of my friends who had them.

[atari4x4]

SierraDan wrote:

Patrols have a pin.

Patrols also don't flex.

[SierraDan]

Don't say that too loud....

[royce]

Jezza86 wrote:

Paul I was thinkin about this but came up withis analogy.
Grab a broom with both hands. Hold it infront of you. Hold it tight in your grip, lower one end of the broom, raise the other. The tension on your wrists and fingers exceeds the tension on your shoulders.

Royce. Dis one ?

Yeah that's pretty much it

[Gwagensteve]

royce wrote:

Steve (not the opinion squad) is there any relation to suspension behavioir and where in relation to the axle the bushes are? Ie if they were more 12 and 6 o'clock rather than 3 and 9

Yes and no Royce. Ford use bushes at 12 and 6 on the radius arm super duties now. It will make no difference to bush deflection, but it will effect where the bushing twist occurs- with axle bushes at 12 and 6 the arm will flex with the axle so all the twist will be done at the chassis. The same amount of bushing deflection still occurs at the axle though.

(Opinion mode on )

I'm quite suspicious of these flexy arms. I think they're mostly wank. Zero (or very low) front roll stiffness is far from ideal, on and off road.

I see the problem as something like this: stock roll stiffness is OK, then peep installs lift springs, makes roll stiffness go up. Then car drives bad, installs caster bushes, car drives good but roll stiffness goes up again, then fits whacky arms and turns the car into a wobbling pig that's hektik for posing on ramps and showing off shiny arms. I think staying at the same roll stiffness as stock is probably all that's required, and if that's no possible without whacky arms, that might be a sign the car is too high

(Opinion mode off)

Steve

[Jezza86]

Gwagensteve wrote:

Steve

but bumpsteer is awesome.
my time again i wouldnt go over 50mm and id lop the guards off and install bigger plastic flairs, like i have siting in the shed.

luckily ill be unemployed sitting in qld in 50 days.

the ratuken (white red bushes) would have a tiny bit of front stiffness, as theres still one bush in the front to compress with the chassis bush.
the adjustment on the rear bush would give a little castor correction when level, and wouldnt resist the change in castor as well because theres 2 bushes where there was previously one supporting the rear axle mount.

[Gwagensteve]

If the ratuken arms are the white ones with the nickel plated articulation bits I'm very suspicious of them. Under power/brakes deflection of the bush on the little arm will cause lots of axle roll. There's also a lot of load on that little bolt that mounts the short link to the main arm.

Steve.

[Jezza86]

haha yeh sorry steve, the white ones with the red bushes are the same design i just found that pic first when i was searching

i got the impression that the short arm had bushes in both ends, further decreasing its castor maintaining qualities.

[Gwagensteve]

I'm sure there is a bush in there, but it looks to be very small and therefore would have to be very stiff and/or have a short life.

[Zook_Fan]

Articulation joints were used and the arm was a torsion bar? You could throw your sway bar away and control the roll stiffness of the car through the diameter of your control arms. As long as it wasn't as stiff as the housing or the brackets it would be the first to respond to the force and therefore rotate and would apply a resistive force similar to the bushes in doing so without the wear out of the bushes.

[Gwagensteve]

My understanding is this is pretty much how the rear of DII's and P38 range rovers work

Steve.

[jimny_timmy]

My ORA arms (old tube style) chewed the rubber bushes to shreds. I replaced them twice then got Bruce to make me some... Reading this is starting to make some sense. Pretty sure my arms are bent slightly from the bushes being a little stiffer/stronger than the rubber ones and hence making the arm the weak point now.

[Mike57]

I think the issue is that your arm is now the strong point. It should be the weak point.

[want33s]

BertZook wrote:

this is the theory behind the superfelx arms

As far as I can tell, the 'superflex' arms ONLY allow more than flex standard arms because the bushes are closer together, nothing to do with them being at '6 & 12'.


Q: How do radius arms work?
A: They don't.

[Zook_Fan]

Mike57 wrote:

I think the issue is that your arm is now the strong point. It should be the weak point.

Definitely not. You want the bush to be the weakest part of the arrangement. Having the arm weaker would be the same as a 100amp fuse on your cigarette lighter. You want the cheapest, more easily replaced part to be the consumerable which is the bush in this situation.

[Gwagensteve]

Want33's- the superior arms also work because there's three bushes not two.