My dad over the years has had several. I think he's had a series i,ii, iii. But had probably 2 of each including ex-Army ones. I think he also had a Landrover 110 or 90 before they were called Defenders. According to him they were great becuase the were so reliable but if they broke then they would be easy to fix.
I just looked up landroverusa.com. The Defender is no longer available to us since 1997. Even at that, there is no way I would take that thing off road. Just simply WAY too expensive. A "proper" off road truck would be a 1985 Toyota Pickup truck (solid axle front and rear) for the tune of around $1000 US, fitted with an ARB air locker in front, and a locker in the rear, a Marlin Crawler dual transfer case with 4:71 gears in each, a six inch suspension lift fitted with 35 inch Mickey Thompson mud tires, etc. Then when you break something, you don't have to worry about the fact that you spent $60,000 on an "off-road" truck (no idea what they sold for, but they definitely were NOT cheap).
Here we go. The first guy climbing in 2nd gear with the rear locker disabled (open diff). And leaf springs are much easier to change out. Just unbolt and drop them down. Makes it much easier for trail fixes when you don't need coil spring compressors and such, and much safer.
Leaf springs, depsite of their old age, are some of the most versatile suspension components of all time. It is unfortunate that people these days overlook all the serious advantages they offer.
Increasing/decreasing stiffness of a leaf spring packs is a simple manner of increasing individula leaf stiffness and/or increasing the number of leaves. You could also manipulate stiffness via the arch angle too. With multileaf packs, progressive springing is VERY easy to achieve. In fact, leaf springs have been quite commonly progressive before the idea of progressive coil springsa ever came to be. This ease of achieving progressive spring allows excellent load capability without seriously affecting traction in low load conditions. For a little real life test, just swap the rear leaf packs of your average OEM hilux with a leaf pack that uses thinner but more numerous leaves whilst maintaing or improving load capacity. You'll be amazed with the improvements in comfort and incidentally, traction over less than ideally flat surfaces.
In the old days, interleaf friction was a desirable trait as dampers of the day were quite franky, absolutely rubbish. These days, interleaf friciton is easily reduced significantly with interleaf teflon/etc inserts. This significantly improves their ability to oscillate quickly and deal with rougher terrain at higher speeds.
Another serious advantage often overlooked is their ability to locate axles effectively without any extra trailing/leading arms or panhard rods, etc. This somewhat negates their greater weight over coil sprung live axles. With current high quality leaf springs, military wraps are used to support the vehicle in the extremly unlikely case that they actually break. BTW, leaf springs are STILL the most durable springs since the metal experiences less stress and strain over their normal working ranges than coil springs. Basically, they take longer to reach metal fatigue.
The moral of this? Don't write leaf sprung live axle suspensions off as inferior to coil springs. Like many things in life, things simple aren't THAT simple.
Go look up rock crawling setups - the ideal for that is over 2 feet of flex (plus a lobster transfer case, proper tyres etc), the vehicles I listed are capable of that with minor mods, and are respectable when stock.
Trouble is, that in this country the Jeeps are the rubbish ones with small wheels (I'm guessing around 14-15" diameter wheels which are about 5 or so across).
If we could get large wheeled versions that would be great.
All the vehicles shown were modified - aka NOT stock - and I was referring to vehicles that are good off-road STOCK. There is only the Defender.
Besides the Defender has another good off-roading trate: It looks even better with a few dents and covered in mud. What other car can boast that?
You can make anything and I mean ANYTHING work off-road if you modify it enough.
About the bestness of leafs.
Yes leaf spring are the best when you are carrying heavy loads. Why do you think lorries have them. But for articulation even the best leafs can't compete with dislocation coils. With leafs you don't need other hardware to locate the axles. BUT when the spring breaks you cannot drive the vehicle without some kind of temporary fix. Where as with coils you are just driving with one corner closer to the ground. Which is better on a dark stormy night?
If leafs are so superior as you say why are coils even used?
Leafs are NOT dead they just have other uses than coils.
Did you even bother to read my post about the Wranglers? They were almost stock, only thing exchanged were the tyres (because stock tyres are usually some compromise, not pure offroad) and a winch (which just makes sense for serious offroading).
Even the Jimny (older model) could do good offroading while being completely stock. I know that, we had both of them.
The Defender is a very good offroad car - but by far not the only one
Please read my post about military wraps. Explains how they can limp home even WITH broken leaves.
If ANY component goes wrong (from those coils/dampers to those axle location links) on a coil sprung vehicle, THEN you're REALLY doomed. A car that rests on its axle is effectively immobillized.
Articulation? You've obviously not heard of many leaf spring related innovations currently on the market. The chief problem of articulation with leaf springs is that since the springs are flat metal plates, they're very resistant to twist. This does have the positive effect of offering enough roll stiffness to NOT need rollbars. With coil sprung live axles, no rollbar = sway out of control unless your springs are STIFF.
The secret to extreme leaf spring articulation? No, it's NOT a simple manner of just using fewer and/or thinner leaves. The secret is in the shackles that hold the springs.
Your average shackle is rigid on the roll plane, disallowing the leaf to rotate freely, causing the leaves to experience torsion, something the leaves resist very well. With shackes that allow the driver to unlock and allow roll axis articulation, the leaves are allowed to twist freely. This results in a practically ideal system that allows excellent articulation off road whilst in the unlocked mode and excellent handling at high speeds in the normal locked mode. Lockable articulated shackles!
The HiLux and Ram pictured are stock. All the models I mentioned (and more) are capable of a similar amount of off-roading as a Land Rover Defender when stock - the Jimny is probably capable of more thanks to its shorter wheelbase and much lighter frame. Saying the wheels are to small at 15" is a misnomer, its the tyre height/width thats increased, not the diameter of the wheel.
But you stated 14-15 inch diameter wheels, specifically. Nothing about tire diameter. With an off-road tire/wheel combination, you want smaller diameter wheels and larger tires. The larger tires allow you to decrease the air pressure and allow the tires to deform around an obstacle thus gripping it better with less chance of puncture from a sharp object.
It just really makes me laugh when I see 4x4 vehicles out on the road with low profile tires mounted to 18+ inch wheels.
I say-1 for 4X4s. I think they look ugly on the road and on TV. if we had 4X4s we'd need a mud autoX and hills and jumps and stuff to hit and smash. And if Monster Trucks came along to LFS I'd sell my Left foot for scientific research.
Do we atleast agree on the point about solid axles and independent suspension?
What amazes me most about this "leafs are best thing known to man off-road" is that if they are so best than why do rockcrawlers mostly use coils? That is the sport where you need articulation in your suspension the most. Yes you can do it in a leaf sprung vehicle and all that but the competition vehicles are mostly fitted with coils. And what about CORR? The trophy trucks are coil sprung and so are the buggies. Why would they not use the best there is?
I am NOT anti-leaf! I LOVE leaf springs! I would like to have a vehicle with leafs! But I know that one with coils would probably be better.
BTW Is it propably or probably? I can never remember.
There are many reasons why leaf springs aren't favoured at the top echelons of off-road racing. Since there are many reasons to this, shall only explain a few of them.
One reason is simple packaging. Corvettes run single plate leaf springs in double wishbone suspensions enjoy many of the benefits of the system, such as the fact that the spring element is situated low in the vehicle (lowered center of gravity) and also the fact that it is lighter than a coilover setup.
However, for long travel systems needed for racing, there are many severe issues. As off-road racing and rallying advanced, the benefits and overall superiority of independant suspension grew. For instance, one of the reasons Pajero Evolutions form both the 90's and the current Pajero EVOs run independant rear suspension is fue to the fact that live axles tend to bend and get out of shape as high speed off-road mile accumulate. The worst part is that unlike independant suspension, which can be adjusted via toelinks to correct misalignment as long as the major suspesion components aren't severely damaged, if they're bent, it's a major pain to fix if it's still fixable. One can also easily see that packing leaves into independant suspension that provides reasonable travel for high speed off-roading is practically impossible, not without very silly, bulky, heavy and underperforming designs. For off road independant suspensions, torsion bars and coil springs are optimum given the packaging constraints. In fact, coilover springs and dampers are ideal for independant double wishbone suspensions, since they allow tight and efficient packaging of springs and dampers whilst allowing all the setup flexibility and adjustability one can do with passive suspension.
In short, leaf springs and independant suspensions with good travel don't mix.
So, what about live axles? Well, as I've mentioned before, multileaf setups offer nice and progessive spring rates, but do experience interleaf friction as a result. This adversely affects their ability to oscillate quickly, a trait required for high speed off-road performance. Of course, I've also mentioned that this is already quite markedly reduced with innovations such as teflon, etc interleaf inserts that severely reduce his problem. But in the end, they still can't oscillate as freely as coil springs of equivalnet stiffness. With coils, one can do conduct the majority of axle oscillation control via dampers alone, allowing easier and more precise fine tuning of the suspension.
These are just some reasons why coil springs are preferred for off-road racing. Other reasons include more predictable axle location. Since leaf springs act as both spring and trailing and leading links, their kinematics are more complex than the relatively more rigid links used for coil sprung live axles.
Too much to mention in one thread/post, but this should answer at least a portion of your question.
I'm guessing from the way that thats worded, you're on about overlanding, ie. high speed trail driving, rather than trials, where getting over the terrain is the challenge rather than going fast ... in trials solid axles will do the job better than independant suspension.
Jamexing, you seem to know alot about suspension. You work in the automotivie industry or is it just a hobby? It's stimulating to argue with one who possesses probably(read very likely) more information on the subject than I.
So we have now established the facts:
Leafs don't react as fast as coils can.
Coils are superior for independent suspension with lots of travel. However, leafs are used with independent suspension on some vans and small lorries. Mercedes Benz Sprinter for an example.
Torsion bars are for saving space. But off road they are not very good.
How can you say that changin the stifnes of a leaf suspension is easier than doing it with coils? Have you ever changed a leaf in a pack? I have and it's a really shitty job. Changing a coil spring is a breeze compared. Granted you need a spring retainer but to change a leaf you need various powertools. Furthermore if you have a dislocating coil suspension you don't even need the retainer. If you are intent on changin the whole pack then it is a pretty straight forward exercise. But carrying a whole pack with you is a bit on the heavy side. And you need two because hardly ever are the rear and front leafs the same lenght. Ofcourse you can make it so and carry a spare that will fit either end.
But still I don't accept your argument about leafs being superior even on slow off-road driving. If that would be the case then why do rock crawlers use coils. It might be easier to do trail fixes on leafs but the articulation you get with coils is a far greater advantage.
With serious off-roading comes serious torque and that causes axle wrap a.k.a. the Leaf killer. Even with leafs you start to need additional elements in your axle locating hardware to battle the effects of axle wrap. Why not just make it a fourlink setup and be done with it.
And this is what happens to the ones with leafs
@mrodgers, if you are using 50" tires those 18" wheels don't look so stupid anymore. But I don't understand people who buy a big 4x4 and but bling bling wheels on it with extra low profile tires. It's just like buying a sports car and puttin 50" tires on it.
The scratchbuilt (or for UK trials classes 'prototype') does have a teensy advantage over the production based Jeep there, lol.
I must admit, I don't 'get' prototypes; at the point where there's no recognisable body (unlike, say, Formula Off Road), it seems the point is lost (that said, I also don't get single-seater racecars).
There are lots of things that'll simply take too long to explain in a proper manner, but here are some of my points.
Notice that I did not at any point say leaf springs are superior to coil sprung live axles. Notice I don't use the word "superior " to describe comparisons of leaves and coils at all. I just describe them as they really are.
And about torsion bars. They do aid packaging in the sense that they free up suspension arm design as there's only a need to contain a damper instead of the whole spring/shock assembly. The good thing with torsion bars is that it allows the springing element (the torsion bars) to be located in low, lowering center of gravity slightly. Just check the underside of a pre-2000 Pajero and you'll get it. Practically, their performance isn't too different from having linear coil springs, given all else is equal/very similar, of course. What limits their travel potential is the fact that they can't be twisted to too severe of an angle before they suffer permanent damage. Basically, it means that your suspension wishbone that the bar attaches to should never be rotated to too severe and angle. With coil springs, a properly selected coil in a coilover setup never need to worry about this. You could of course increase travel and overall performance (on and OFF road) by lengthening the wishbones so they travel much further for a given angle. This applies to all independant suspensions. Isuzu applied this principle to their isuzu troopers and compensated for the longer arms with thicker bars and frankly, it worked very well. Another great thing with torsion bar double wishbone suspension is the ease of adjustability of ride height. Just jack the car up and twist the adjuster screws and wallop, you could easily get some reasonable lift or correct for differences in corner weights. The only problem is that it is impossible to get progressive springing with the torsion bars alone. That would require special "bump stops" like those that porsches use. Anyway, no one has found an elegant way besides the use of special "bump stops" to achieve progressive springing.
And yes, it is EASIER to get long travel coils. That's one reason why they're favoured. A coil spring is in fact the same thing as a torsion bar, but packaged differently. They are both solid round bars of elastic material, and they both work on the principle of twisting the bars to generate force. What makes coil springs better overall for off-road racing in general, fast and slow, is the fact that getting a very precisely designed and controlled progressive behavior is so easy with coils. Just make coils with differing number of coils per spring length along its length, OR you could just stack more coils in series.
I'm quite aware of leaf destruction due to axle wrap under acceleration, etc. Frankly, I've not seen such and incident that's NOT caused by some silly leaf pack setup or even sillier driving. I'm quite aware that in the quest for ridiculous travel for a given length of leaf pack, people resort to ever fewer and ever THINNER leaves. As I've said leaves both provide springing AND axle location, and how on earth do you expect ridiculously thin main leaves to support your car properly let alone withstand axle warping torque? You can safely attain significantly more travel safely by using longer leaf packs, though obviously packaging issues don't allow one to go too far down that path. With coils though can somewhat get away with super soft coils by using 5-link or so to stabilize the axle somewhat. And of course, leaf packs aren't light nor compact, attributes coil spring provide easily. Composite leaf packs can provide all the benefits of progressive springing and severely reduce the weight issue, though unfortunately there aren't many the market yet. i know how leaf packs are changed. The good news is that they require less tools (no need for spring compressors, etc) and conceptually, they're easier to work with as the basic design is so simple. The bad news is of course it's more a case of needing more brute force to get it done.
The moral of the story? Don't resort to using ridiculously thin main leaves to gain travel and you'll do just fine. Remember, it does double duty, so keep it sufficiently strong. Instead, just use more and thinner leaves underneath to gain more travel via more progressive springing. The best plan would simply be to use the lockable articulated shackles that allow excellent cross axle articulation safely. This remove the anti twist problems and allows great improvements in travel without making the leaves ridiculously thin (aka WEAK). Provides excellent rock crawling travel at low speeds via the release of a few pins. For high speed runs, just keep it locked.
Note that the corvette application I mention uses TRANSVERSE leaf plates in independent double wishbone suspension, so leaf wrap issues don't really apply.
In short, weight, packaging and ease of axle/wheel control, etc, all lead to the domination of coil sprung live axles for slow off-roading and independent coil-over suspension for high speed off-road races.
You and I don't agree on a lot of things, and I sometimes think your style of posting leaves a lot to be desired, but I totally agree with what you are saying in this matter, and can confirm it's accuracy (albeit not totol accuracy, but we haven't got room for a full report on the comparison of springing mechanisms!). I just wish I could be bothered to write as much as you do