Thread: Flex from suspension

Originally Posted by discowhite

so does the right spring rates!


yep dislocated springs are absolute crap dont even go there!!!!!
i really wish ide left the sway bars on! just dosnt work at all

cheers phil

Your right Phil, but now you've completely wrecked the car, I know you wont be happy until you have a stock standard car. Tell you what. I'll be generous offer you $1001.50

My point was the design of the rear is a lot more amenable to articulation than the front - so most coillers (d2 excepted) have much better rear travel than front

i agree 100%
the comparrison between a 3 link front an a std rover setup is like chalk and apples!
the front of a rover has so many binding points its hard for it to flex. my front at the moment is limited by the tyres stopping on the shock towers.

I bet if you secured both ends of your coils and drove through that again, there would be little or no difference to overall travel, but the front would be flexing a bit more than it is

i have but not with the current setup. i did it when it had standard springs and longer shocks, honestly i couldnt tell the differance except for the banging sound on relocation maybe the noise was resetting my brain.

Some people like dislocated springs - fine - IMHO they make a landie less stable on side slopes etc.

i own a 90 im used to unstable

Who said anything about sway bars???

my attempt at sarcasim.....dobbo got it

cheers phil

No one said that dislocated couldn't be setup to work well, Just the D90 with the scorpion kit isn't. All rear flex.

Yours has been setup well and spring rates look to be spot on(going by the photo). Would be interesting to see how more balanced it would be with the rear captive. But as you said its hard to get much more travel out of the front end design

Here are some pictures of my car during testing. I run a 3-link with panhard rod in the front end and 3-link with A-frame in the rear. I was running standard Range Rover front springs front and rear, but now use 1" lift versions in the front but standards still in the rear

Originally Posted by discowhite

i agree 100%
the comparrison between a 3 link front an a std rover setup is like chalk and apples!

cheers phil

whats this 3 link business I,ve hear 4 link but whats 3

The main problem with dislocating springs is with stability on side slopes but the other thing is that there isnt really much advantage with having you wheel hanging down unloaded as as soon as it has drive it will lift and you will get very little drive from that wheel.

Yes it looks good with that much flex but it's not much real advantage off road.

Well there's my 2 cents worth..

Originally Posted by ROVERNIT

whats this 3 link business I,ve hear 4 link but whats 3

A free body (in space) has 6 degrees of freedom. Translation in three directions (x,y,z) and rotation about 3 axii (xyz).

An axle needs to be restrained to have only 2 degrees of freedom. 1 translation (vertical movement) and 1 rotation.

4 links are required to restrain the other 4 degrees of freedom.

What is generally referred to as a 3 link, has to have a 4th link, which is the panhard rod. BTW some people erroneously call radius arms plus panhard, a 3 link. A radius arm is not a link - by defenition a link can only resist a force aligned with it's axis (clearly, a radius arm can resist axial plus rotation at 1 of it's ends).

The 3 link plus panhard has 2 lower links (like the rear lower links of a rover), a single upper link (which may be offset to clear the engine) and the panhard.

The offset of the upper link can be designed to counter the torque roll when climbing a hard obstical (can be the difference between rolling or not).

Alternatively, some front, 3 links have 1 lower link, 2 upper links and a panhard. The disadvantage of this arrangement is the single lower link has to resist high compressive loads when braking in an emergency.

When braking the front lower links are in compression and the upper links are in tension. For equilibrium, the compression force in the lowers is equal to the braking force plus the tension in the upper link.

Edit
The radius arm front suspension resists more than 4 degrees of freedom (over restrained). They only work because of give in the bushes. As soon as the bushes stop flexing the suspension binds. This is why the front suspension does not articulate as well as the rear.

4 link plus panhard suffer the same problem, but the total flex of the bushes can allow more articulation than radius arms.

A good, triangulated 4 link can be designed without any handling or articulation problems, but is difficult to get the geometry of upper links right with the engine in the way.

The good thing about radius arms is, they can be designed for good anti-dive during braking. A 3 link plus panhard can be designed for the same amount of anti-dive. With 4 link plus panhard, it is more difficult to get good ant-dive and good articulation (depending on the bushes).

Originally Posted by Bush65

A free body (in space) has 6 degrees of freedom. Translation in three directions (x,y,z) and rotation about 3 axii (xyz).

An axle needs to be restrained to have only 2 degrees of freedom. 1 translation (vertical movement) and 1 rotation.

4 links are required to restrain the other 4 degrees of freedom.

What is generally referred to as a 3 link, has to have a 4th link, which is the panhard rod. BTW some people erroneously call radius arms plus panhard, a 3 link. A radius arm is not a link - by defenition a link can only resist a force aligned with it's axis (clearly, a radius arm can resist axial plus rotation at 1 of it's ends).

The 3 link plus panhard has 2 lower links (like the rear lower links of a rover), a single upper link (which may be offset to clear the engine) and the panhard.

The offset of the upper link can be designed to counter the torque roll when climbing a hard obstical (can be the difference between rolling or not).

Alternatively, some front, 3 links have 1 lower link, 2 upper links and a panhard. The disadvantage of this arrangement is the single lower link has to resist high compressive loads when braking in an emergency.

When braking the front lower links are in compression and the upper links are in tension. For equilibrium, the compression force in the lowers is equal to the braking force plus the tension in the upper link.

Edit
The radius arm front suspension resists more than 4 degrees of freedom (over restrained). They only work because of give in the bushes. As soon as the bushes stop flexing the suspension binds. This is why the front suspension does not articulate as well as the rear.

4 link plus panhard suffer the same problem, but the total flex of the bushes can allow more articulation than radius arms.

A good, triangulated 4 link can be designed without any handling or articulation problems, but is difficult to get the geometry of upper links right with the engine in the way.

The good thing about radius arms is, they can be designed for good anti-dive during braking. A 3 link plus panhard can be designed for the same amount of anti-dive. With 4 link plus panhard, it is more difficult to get good ant-dive and good articulation (depending on the bushes).

So in the short your comprimsing something wether it be dive under breaks or articulation or vise versa

Originally Posted by Bush65

A free body (in space) has 6 degrees of freedom. Translation in three directions (x,y,z) and rotation about 3 axii (xyz).

An axle needs to be restrained to have only 2 degrees of freedom. 1 translation (vertical movement) and 1 rotation.

4 links are required to restrain the other 4 degrees of freedom.

What is generally referred to as a 3 link, has to have a 4th link, which is the panhard rod. BTW some people erroneously call radius arms plus panhard, a 3 link. A radius arm is not a link - by defenition a link can only resist a force aligned with it's axis (clearly, a radius arm can resist axial plus rotation at 1 of it's ends).

The 3 link plus panhard has 2 lower links (like the rear lower links of a rover), a single upper link (which may be offset to clear the engine) and the panhard.

The offset of the upper link can be designed to counter the torque roll when climbing a hard obstical (can be the difference between rolling or not).

Alternatively, some front, 3 links have 1 lower link, 2 upper links and a panhard. The disadvantage of this arrangement is the single lower link has to resist high compressive loads when braking in an emergency.

When braking the front lower links are in compression and the upper links are in tension. For equilibrium, the compression force in the lowers is equal to the braking force plus the tension in the upper link.

Edit
The radius arm front suspension resists more than 4 degrees of freedom (over restrained). They only work because of give in the bushes. As soon as the bushes stop flexing the suspension binds. This is why the front suspension does not articulate as well as the rear.

4 link plus panhard suffer the same problem, but the total flex of the bushes can allow more articulation than radius arms.

A good, triangulated 4 link can be designed without any handling or articulation problems, but is difficult to get the geometry of upper links right with the engine in the way.

The good thing about radius arms is, they can be designed for good anti-dive during braking. A 3 link plus panhard can be designed for the same amount of anti-dive. With 4 link plus panhard, it is more difficult to get good ant-dive and good articulation (depending on the bushes).

It took me 4 times reading it but I think I get it now.