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robhybrid
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I am about to build a buggy as I have wrecked my 90 in 5 years of winch challenge.

Has anybody got any tips on suspension set up I am looking for silly articulation, possibly limited with a winch to axle.

I have fancies for 1 link/reverse A possibly with a watts linkage across the back and with a panhad rod across the front.

I know Chris Abel had missing link on the front of his old portal axled rr -now Kevs.

Everybody seems to favor 4 link but I like the under body protection of reverse A.

What are the advantages and disadvantages?

I have heard that Reverse A can tend to self steer, was hoping to fix with watts likage.

For silly articulation is my only option one of X eng's joints, front not as severe might use a landrover a frame joint.

Is there a larger version of the X eng Joint available or what else will allow silly twist plus up and down movement plus have a little rubber type give.

My buggy will use landrover axles and 35" simex as I already have them, I intend on trying to keep the finished weight below 1000kg.

The buggy will only have low box so max speed 40?

Hopefully getting a new phone with camera in the next few weeks so I might do a build wright up when I get started.

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Why the obsession for silly articulation?

Crazy articulation is overrated. Unless it'll be an RTI ramp queen.., better to get a front-rear balanced suspension. That, with lockers f/r will work very well. The rear suspension is actually not that bad for a stock truck, it's the front that really needs improving. A 3link up front, lengthened A-frame and radius arms and retain the springs.

Building a buggy and keeping LR axles? :blink: Why?

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I compete in winch challenge events and intend on doing a few trials in the future I want the back to be more than capable and for me to be able to put a limit by my own straps.

I like the idea of the front being tighter than the back as I generally drive forward over obstacles and if the vehicle tends to move with the front axle I am more likely to get a feel for the vehicles limitations before it is too late.

I firmly believe that the more supple the suspension, the less stress there is on the half shafts/ drive line.

I want to use the lockers to help me out when winching not a switch on and forget.

I am keeping lr axles because I have already got them along with tires.

I intend on my whole budget being less than what a new set of axles and tires would cost.

I hope with the reduced vehicle weight the axles wont be under as much strain.

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if you want balanced suspension, i would be tempted with disco 2 front radius arms with a johnny joint on the end instead of big bush and slotted bushes on the axle ends with panhard rod. Same setup front and back. If you get your weight distribution 50/50 then you will have even flex on all 4 corners.

you can get good flex with that - especially if you lengthen the arms as well so they basically meet in the middle of the truck. Theres a chap who has done something simillar to his disco buggy on pirate and he is maxing out the full range of movement on 14" travel airshocks.

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I think Nicks90 has a sensible idea there and one that can be dispatched on a low budget. The flex will be more than enough, plus it will be light, simple and reliable. This will also be better at speed than missing links, A frames, single links etc.

The other option I would recommend is double triangulated 4 link front and rear using johnny joints / creaper joints or similar. Keeping the links as long as possible. The big advantage is that the lower links can be brought up to above the bottom of the axle to improve clearance on the small tyres.

This Hilux belongs to a guy called Nitteberg on Pirate and maxes out 18" airshocks:

post-5209-004860900 1291382531_thumb.jpg

post-5209-093133500 1291382788_thumb.jpg

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thanks for the photos the complete vehicle cage set up isn't a million miles of what I have got planned.

It has got me thinking a little.

can anyone tell me the advantage or disadvantage of the axle moving in an ark with the suspension landrover front or 1 link, compared to the axle moving parallel landrover rear or multi link?

could I do reverse A bushed to pivot at the axle end with 2 links above similar to above photo? or a modified landrover rear upper A.

Has this got a advantage over reverse A fixed solid to the back axle?

I want to see if I can make the bottom of the reverse A into a skid so I don't have to worry about the axle getting caught in rocks or tree roots I could winch over regardless.

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Yours won't look quite the same on 35's and landy axles :ph34r:

I really like 1 link suspension, as it can be made simply and very strong with very few joints to wear

If your staying with a steering box a ballistic jointed panard rod would offer more travel than most shocks would allow.

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I know but I dont know of anyone willing to swap a set of ready to go mog or volvo axles and tires for my lr items :(

Seen some strange shaped panhad rods on other forums , is it so it will clear the chassis?

saw a couple of great pictures that proved pan had rod would allow more articulation without fouling body than wats linkage.

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I firmly believe that the more supple the suspension, the less stress there is on the half shafts/ drive line.

That is correct up to a certain point. If it isn't correctly set up you'll get hopping on steep slopes, and that's what breaks axles.

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The whole articulation thing is a double edged sword - to a much greater extent than I realised when I started building my 'buggy'.

I like many had assumed that supple long travel suspension was best - and built something where you could lift one tyre 52" off the ground before any other lifted.

In a traditional cross axle - this works great. However, people setting up winch challenges tend not to make them such that with equal front & rear travel, the vehicle will stay level - they often tend to be traversing a side slope with cross axle.

Why is this a problem? Because most of the vehicle weight is on the down-hill rear wheel. The suspension fully compresses and you quickly get in to a situation where that wheel is tucked under the vehicle to the extent that the vehicle can roll over that wheel and topple.

It'a axtually the same thing as happens to 3 wheelers if you corner too fast - because there is no front wheel to push the diagonally opposite rear wheel down, it lifts and rolls.

In conclusion, I think that the suspension, even if it has loads of travel, needs to be stiff enough to hold the diagonally opposite wheel on the ground.

How stiff is this?

It depends on a number of factors including the wheelbase and track of the vehicle, it's weight and the steepness of slope you want to climb.

Likewise on a side slope, the vehicle leaning towards the down hill side can topple it earlier than you might expect - and in this case you have two springs pushing you back up.

Calculating the spring rates etc is going to be difficult - so maybe better to go for a trial & error solution. For that reason more than any, I favour the Fox Air Shox as you can set them up however you want.

The bottom line is that as you increase the travel, the increase becomes less & less worthwhile because you start to loose stability on slopes.

Using a small winch to pull up the centre of the axle might work well - as it will stiffen up the suspension as well as lowering the G of G, improving the slope stability.

Si

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I had got fancies of putting my rear winch rope through a loop on the axle before exiting the rear fair lead.

hooked on to rear and pulled tight it would tighten up rear axle/limit travel,

whilst winching it would help keep rear axle from sinking in the gloop or from being pulled under it self?

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Si, a solution for you could be ORIs. Apparently they do really well on sideslopes, and the only thing they don't do well is desert racing because they overheat. If I had the money I'd definitely build something with crazy amounts of travel and ORIs.

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In a traditional cross axle - this works great. However, people setting up winch challenges tend not to make them such that with equal front & rear travel, the vehicle will stay level - they often tend to be traversing a side slope with cross axle.

I've noticed something similar. I have a 3 link front and, +5's and X-Springs, and whilst I've not been close to tipping over it has leaned far more on a side slope than a similarly sprung std travel 90. It meant I had clearance issues on down hill obstacles that he didn't.

I did consider that if needed I could use a ratchet strap to stop it leaning so far another time.

Si

Incidentally - I sent you a pm through here a about 10 days ago or so, did you get it?

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At the moment my 109" is sprung over on LC80 axles. It's got rear springs up front, parabolics, and 14" travel shocks. On the front it uses the full stroke of the shocks, on the rear it doesnt.

It's got between 95-100cm of total articulation, far more than many coilers. It never felt unstable under any circumstances. At least that's one goodthing about leafs, the torsional twist adds springrate, works kinda like a swaybar. The width of the axles also help with stability.

IMG_8167.jpg

As I want to go to really big tyres (38.5 creepies), turbo and an Orion Tcase (doubles low gear to 82:1)I might run into trouble with the parabolic suspension (axlewrap). And as I want to constantly improve things I've decided to go 3link front, 4link rear with Fox coilovers. I know that articulation from the front end will be the same, the rear will improve. That will give me all the articulation I need. Even know it rarely lifts a wheel of the ground.. When needed I'll add an offroad swaybar to increase stability on sideslopes without going to stiffer springs.

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The whole articulation thing is a double edged sword - to a much greater extent than I realised when I started building my 'buggy'.

I like many had assumed that supple long travel suspension was best - and built something where you could lift one tyre 52" off the ground before any other lifted.

In a traditional cross axle - this works great. However, people setting up winch challenges tend not to make them such that with equal front & rear travel, the vehicle will stay level - they often tend to be traversing a side slope with cross axle.

Why is this a problem? Because most of the vehicle weight is on the down-hill rear wheel. The suspension fully compresses and you quickly get in to a situation where that wheel is tucked under the vehicle to the extent that the vehicle can roll over that wheel and topple.

It'a axtually the same thing as happens to 3 wheelers if you corner too fast - because there is no front wheel to push the diagonally opposite rear wheel down, it lifts and rolls.

In conclusion, I think that the suspension, even if it has loads of travel, needs to be stiff enough to hold the diagonally opposite wheel on the ground.

How stiff is this?

It depends on a number of factors including the wheelbase and track of the vehicle, it's weight and the steepness of slope you want to climb.

Likewise on a side slope, the vehicle leaning towards the down hill side can topple it earlier than you might expect - and in this case you have two springs pushing you back up.

Calculating the spring rates etc is going to be difficult - so maybe better to go for a trial & error solution. For that reason more than any, I favour the Fox Air Shox as you can set them up however you want.

The bottom line is that as you increase the travel, the increase becomes less & less worthwhile because you start to loose stability on slopes.

Using a small winch to pull up the centre of the axle might work well - as it will stiffen up the suspension as well as lowering the G of G, improving the slope stability.

Si

All true, but one more factor is important here: roll centre position. Basically, this is the axis over which the body pivots. The higher this point is, the less body roll you have, to the point that if your roll centre is at the same hight as the centre of gravity, there wont be any body roll at all. Of course there are other problems you need to consider, beacuse the ride would be very strange with this setup, but it is certainly a factor to consider. Also the lower the centre of gravity the less roll, as you mentioned.

Daan

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I am about to build a buggy as I have wrecked my 90 in 5 years of winch challenge.

Has anybody got any tips on suspension set up I am looking for silly articulation, possibly limited with a winch to axle.

I have fancies for 1 link/reverse A possibly with a watts linkage across the back and with a panhad rod across the front.

I know Chris Abel had missing link on the front of his old portal axled rr -now Kevs.

Everybody seems to favor 4 link but I like the under body protection of reverse A.

What are the advantages and disadvantages?

I have heard that Reverse A can tend to self steer, was hoping to fix with watts likage.

For silly articulation is my only option one of X eng's joints, front not as severe might use a landrover a frame joint.

Is there a larger version of the X eng Joint available or what else will allow silly twist plus up and down movement plus have a little rubber type give.

My buggy will use landrover axles and 35" simex as I already have them, I intend on trying to keep the finished weight below 1000kg.

The buggy will only have low box so max speed 40?

Hopefully getting a new phone with camera in the next few weeks so I might do a build wright up when I get started.

There are advantages with what you call reverse A suspension.

The issue with roll steer, as with any other style of suspension is to do with the slope of the suspension roll axis. The closer the suspension roll axis is to parallel with the road the less roll steer parallel or slightly down (1 or 2 degrees) is best.

The height of the panhard or watts link is one factor in the slope of the suspension roll axis - a panhard is no better or worse than watts link in regard to roll steer, it is all about where they are mounted height wise and how that affects the suspension roll axis.

I would like something a lot stronger than the standard X eng joint for a reverse A as you would only have one joint that has to more than the two used in normal rover rear suspension.

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snip ...

I like the idea of the front being tighter than the back as I generally drive forward over obstacles and if the vehicle tends to move with the front axle I am more likely to get a feel for the vehicles limitations before it is too late.

... snip

Get over it. Don't invent excuses for badly balanced suspension - learn to read the situation better.

Go for balanced articulation that can be easily driven over obstacles that are more difficult than you could tackle with your poorly balanced suspension.

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All true, but one more factor is important here: roll centre position. Basically, this is the axis over which the body pivots. The higher this point is, the less body roll you have, to the point that if your roll centre is at the same hight as the centre of gravity, there wont be any body roll at all. Of course there are other problems you need to consider, beacuse the ride would be very strange with this setup, but it is certainly a factor to consider. Also the lower the centre of gravity the less roll, as you mentioned.

Daan

That is correct. Low roll centres (relative to height of COG) result in the sprung mass flopping over to the downhill side, leading to roll over.

The big down side of high roll centres raises it head through the dynamics that occur when driving fast on rough uphill tracks that induce a good deal of articulation.

High roll centre forces the sprung mass to move transversely relative to the axle and wheels during axle articulation.

Just another thing where we need to strike the best compromise for the conditions that are encountered, but much easier if the COG is kept as low as possible.

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I would like something a lot stronger than the standard X eng joint for a reverse A

I agree - it's not what they were designed for.

As a joint in a radius arm, the force is entirely longitudinal and the joints have a 6 x margin in the failure load. In an A Frame, there is significantly more force but more significantly, there is a high, cyclic shear force which tends to cause fatigue problems.

Nick is using them on his inverted A Frames, as will I on the next project. We have had a couple of the balls shear on events - which is not ideal. We are having some made from EN24 which should prove more resilient.

If not - I have a cunning plan! I have another type of joint in mind which should be pretty good in that application.

Si

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What about cutting the chassis in the middle and welding in a pivot, like a dumper truck? not a steering one but one that works longitudinally to allow immense articulation but you could then use standard or stiffer springs.

Something a bit like this then?

This is where I get the idea that the suspension needs to have some resistance as there are some situations, such as climbing a slope diagonally, where resistance to articulation is critical.

Si

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Get over it. Don't invent excuses for badly balanced suspension - learn to read the situation better.

Go for balanced articulation that can be easily driven over obstacles that are more difficult than you could tackle with your poorly balanced suspension.

:rolleyes::)

unfortunately when the red mist comes down reading the situation better goes out of the window at times.

Yes I have rolled my current truck once or twice.

I just thought if the front was a little tighter than the rear I might stop before I go too far.

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There are advantages with what you call reverse A suspension.

The issue with roll steer, as with any other style of suspension is to do with the slope of the suspension roll axis. The closer the suspension roll axis is to parallel with the road the less roll steer parallel or slightly down (1 or 2 degrees) is best.

The height of the panhard or watts link is one factor in the slope of the suspension roll axis - a panhard is no better or worse than watts link in regard to roll steer, it is all about where they are mounted height wise and how that affects the suspension roll axis.

I would like something a lot stronger than the standard X eng joint for a reverse A as you would only have one joint that has to more than the two used in normal rover rear suspension.

so from what you are saying have a look at my poor picture:-

panhard rod.JPG

would the panhard rod set up on the right be better than the pahard rod on the left due to it being mounted higher up on the axle?

steering not involved in this question.

I would guess the flatter the panhard rod the better also? i.e right hand side higher or left hand side lower.

got any tips for further reading (without frying my brain) :blink:

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I've always heard it's best to have your panhard horizontal at ride height. As long as it's horizontal, the rest shouldn't matter. I think placement is more often decided by how easy it is to brace that certain point. Having something stick high up on an axle isn't going to be easy to brace, but having something sticking out from under the chassis should be a fair bit easier.

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