What problems are common with rough road towing?

[boxcar]

Actualy Paul is partialy correct. Independent suspension does help the on road ride. (Not a bad thing) But it's the offroad articulation that I was refering to. Leaf spring suspensions are not capable of the same type or rainge of articulation that a well designed independent system is. But I agree with him that simple is best in some or even most cases . And again I will state that an independent system is simple. Just not as inexpensive to build. And no I don't race my toys. I do build a few race cars though and have never seen the need for computer controled suspension aids. Maybe that's a Land Rover thing???? Just joking!!!!
I envy him Australia though. I'd love to wheel the outback. Oh well at least we have Baja. Moab, Lo-Lo pass,etc. etc...Boxcar... Cheers

[StormRider]

Actualy Paul is partialy correct. Independent suspension does help the on road ride. (Not a bad thing) But it's the offroad articulation that I was refering to. Leaf spring suspensions are not capable of the same type or rainge of articulation that a well designed independent system is.

Leaf spring solid axle suspensions are capable of more articulation than your standard independent suspension systems:


Coil spring solid axle suspensions are even more capable in the articulation department:


Independent suspension articulation is limited in standard vehicle designs due to the short arms used.

Where independent suspensions really shine is their ability to isolate and control shock forces from the road, while maintaining wheel camber for better traction.

On a trailer, the suspension type has very little to do with articulation since there's only 3 points of contact- 2 wheels and the coupler. With non-ball type coupler (pintle, specialty offroad couplers), articulation is unlimited.

Independent suspensions on trailers allow for a smoother ride at higher speeds on rougher terrain.

[boxcar]

I guess I should have used the words : idependent traval rather than articulation in reference to trailers...

I noticed that you posted pics of highly modded jeeps (cool) as your refrences to articulation and then compare them to stock independent rides. I beg to differ .... I will post pics of a fue highly modded independents later to give us a true comparison....

[StormRider]

I wouldn't call the pictured rigs highly modified, your talking about less than $4k in suspension modifications and wheels. But, here's what a stock Jeep JK rubicon can do: http://www.youtube.com/watch?v=kag572M-dJA

Now this is highly modified :)

[eamarquardt]

I wouldn't call the pictured rigs highly modified, your talking about less than $4k in suspension modifications and wheels. Now this is highly modified :)

Not to quibble, bicker, or otherwise disgree but for me 4K in suspension mods equals "highly modified" (or at least my checking balance would be highly modified after writing the checks). I'd like to understand and appreciate what constitutes highly modified in your book.

Clearly, we agree to disagree, but we don't have to be disagreeable about it!

I gather "articulation" is the difference in postion (height) of one (front or rear) wheel to the wheel (front or rear) on the opposite side of the vehicle and solid axles are capable of considerable articulation even though the wheels are connected by a solid axle. Articulation is the ability to keep both wheels(front or rear) in contact with the ground at the same time and is not dependant on the two wheels ability to move independantly of another? Do I have the right idea?

Cheers,

Gus

[Steve F]

I guess I should have used the words : idependent traval rather than articulation in reference to trailers...

I noticed that you posted pics of highly modded jeeps (cool) as your refrences to articulation and then compare them to stock independent rides. I beg to differ .... I will post pics of a fue highly modded independents later to give us a true comparison....

Why is there an assumption that there is no flex in the leaf spring on the side that hits the bump and lots of rebound, you cant have the rebound with no movement in the spring in the first place In fact a leaf spring is less likely to have a lot of rebound as the friction between the leafs reduces rebound, a coil spring has no friction and is much more likely to rebound and goes nuts without a shock. You can get away without a shock on leaf springs but ideally you have supple long leaf pack designed for the weight of the TD and stick on some shocks.

My offroad TD runs leaf springs and its also due to simplicity and easy of repair etc. I've driven for over 3000kms here in Australia without seeing any sealed roads and some of those unsealed roads were terrible. Bulldust and corrugations will tear anything apart if care isn't taken or you drive at the wrong speed for the terrain, the advantage of leaf springs is if something does go wrong it's easily fixed on the trail or in the bush.

Cheers
Steve

[StormRider]

I wouldn't call the pictured rigs highly modified, your talking about less than $4k in suspension modifications and wheels. Now this is highly modified :)

Not to quibble, bicker, or otherwise disgree but for me 4K in suspension mods equals "highly modified" (or at least my checking balance would be highly modified after writing the checks). I'd like to understand and appreciate what constitutes highly modified in your book.

Really talking about different worlds here. 4k is quite a bit of money for most hobbies, however when you talk about motorsports, it's a rather small sum of money.

Here's an idea of highly modified: UROC Rockcross vehicles

Clearly, we agree to disagree, but we don't have to be disagreeable about it!

Not disagreeing with you at all. I'm simply pointing out that 1. Stock independent suspension on a 4 wheel vehicle is not going to come close to the amount of articulation a solid axle coil spring vehicle has.
2. Independent suspensions in offroad race vehicles require a highly modified chassis and cost far more than common solid axle suspension upgrades.
3. Leaf springs are capable of more articulation than an independent suspension, especially when you compare cost.

I gather "articulation" is the difference in postion (height) of one (front or rear) wheel to the wheel (front or rear) on the opposite side of the vehicle and solid axles are capable of considerable articulation even though the wheels are connected by a solid axle. Articulation is the ability to keep both wheels(front or rear) in contact with the ground at the same time and is not dependant on the two wheels ability to move independantly of another? Do I have the right idea?

Exactly. And the entire discussion about articulation is moot when you talk about trailers, since there's only 2 tires involved :)
If you use a offroad type coupler (such as a pintle) that doesn't limit rotation, you could weld the axle solid to the trailer frame, and that trailer is going to be able to "articulate" compared to the tow vehicle right to the point of falling over, and still have both tires on the obstacle.

Why is there an assumption that there is no flex in the leaf spring on the side that hits the bump and lots of rebound, you cant have the rebound with no movement in the spring in the first place Wink In fact a leaf spring is less likely to have a lot of rebound as the friction between the leafs reduces rebound, a coil spring has no friction and is much more likely to rebound and goes nuts without a shock. You can get away without a shock on leaf springs but ideally you have supple long leaf pack designed for the weight of the TD and stick on some shocks.

You get more rebound in a solid axle setup because some of the force of the bump is transferred to the other side via the axle, because the axle is a simple lever. When one tire goes up, it levers against the other tire, transferring some force to the far side suspension.

My offroad TD runs leaf springs and its also due to simplicity and easy of repair etc. I've driven for over 3000kms here in Australia without seeing any sealed roads and some of those unsealed roads were terrible. Bulldust and corrugations will tear anything apart if care isn't taken or you drive at the wrong speed for the terrain, the advantage of leaf springs is if something does go wrong it's easily fixed on the trail or in the bush.

Cheers
Steve

The advantage to an independent suspension is that you can drive faster over rough terrain compared to a similar solid axle (leaf, coil spring, airbag). The value of the cost/complexity of an independent suspension vs solid axle on a trailer is entirely the decision of the individual.

[eamarquardt]

I wouldn't call the pictured rigs highly modified, your talking about less than $4k in suspension modifications and wheels. Now this is highly modified :)

Not to quibble, bicker, or otherwise disgree but for me 4K in suspension mods equals "highly modified" (or at least my checking balance would be highly modified after writing the checks). I'd like to understand and appreciate what constitutes highly modified in your book.

Really talking about different worlds here.

Yes, and I think you recognized that I was just teasing you!

Now, let's discuss the value of minimizing "unsprung" weight in the quest for a fast responding high speed off road suspension system (not a requirement in rock crawling as I see it).

Cheers,

Gus

[boxcar]

Lets se .Stock leaf spring vs. stock independent.Try Jeep yj vs Hummer in stock format. The Hummer has a ton more articulation, A TON . As to the aformentioned jeep pics: The cj has an SOA kit shack reverse kit and what looks like YJ springs / the YJ has coils and 2 link (YJ's come with leafe springs) both Jeeps have had total suspensionn conversions. And extensive frame mods. Not to mention that $4000 will buy you eather Jeep in stock format. I call that highly modded....
On to the trailer /independent suspension is not linked by the axle (side to side)
This helps the trailer maintain a level ride when comeing in contact with an obstical. You are corect an independant system does need to be equiped with shocks (AS I MENTIONED EARLIER) With out writing a book here you can not isolate the spings on solid axle trailers so when an obstical is hit by one wheel the compresion is transfered to the other side of the trailer causing tiping.
Rebound is not controled by the friction between the leafs to a great extent. There is just not eanough movement between the leafes. . Thats why shocks were invented.And I was recomending air bags not coils ...It all comes down to OPTIMAL suspension systems best vs worst when ride and controle is considered . I stand firmly behind- Trailing arms, Air bags, And shocks...Boxcar...PS: i thought we were discusing trailer suspension here????

[boxcar]

just a few pics of MOVING RIGS.Slightly over 2 mph.... Boxcar

[StormRider]

Actualy Paul is partialy correct. Independent suspension does help the on road ride. (Not a bad thing) But it's the offroad articulation that I was refering to. Leaf spring suspensions are not capable of the same type or rainge of articulation that a well designed independent system is.

I was simply pointing out that in fact, a well designed leaf spring solid axle is capable of just as much, if not more, articulation than an independent suspension. The modified jeeps I linked pics to are certainly lighter on the wallet than desert race trucks.

Stock leaf spring vs. stock independent.Try Jeep yj vs Hummer in stock format. The Hummer has a ton more articulation, A TON

From a truck trend 2004 article:http://www.trucktrend.com/roadtests/ultimate/163_0412_4x4_challenge/index.html


The H1 Hummer gets spanked pretty badly on the RTI ramp by the Jeep TJ Rubicon. The limited wheel travel of the H1 is visible here:


RTI numbers are more difficult to find on the stock YJ Jeep, however, secondary reporting from here from a late 90s Four Wheeler Magazine article:
http://www.offroaders.com/info/tech-corner/rti.htm
'93 AM General Hummer: 385
'96 Jeep Wrangler: 357
'96 Jeep Wrangler w/Pro-Comp 2.5-inch lift:532
'97 Jeep Wrangler:532

Is showing a stock YJ keeping up with the $100K H1 on the RTI ramp, and is easily and cheaply upgraded to out perform the H1 in articulation.

Not to mention that $4000 will buy you eather Jeep in stock format. I call that highly modded....

$8k for a jeep and suspension modifications is a far cry from $100k H1s and desert race trucks.

[PaulC]

I hope Kevin has decided what suspension he will be using after such an interesting debate

Get back to trailers and TD's Boys and Girls

Cheers
Paul

[boxcar]

Look lets stop playing political games here....
your # are flawed :
you list a
1993 Hummer ( I am asuming an H1) at 385
a 1996 Wrangler at 357
A modified 1996 wrangler at 532
and a 1997 Wrangler at 532
Wranglers were not built in 1996 It was a dead year(re tool for the TJ)
so I am asuming some one screwed up....and may have posted # for the 1995 YJ ???????
The 1997 Wrangler (TJ) was not leafe spring It is a 2link coil spring suspension system....And prob. the best Jeep suspension (articulation wise) ever designed. In point of fact none of the rigs you show stats for have leaf spring suspensions. Thay are all 2 or 4 link and coil .
Now look up the numbers for a 1997 H1 not a 1993
Then a modifyed 1997 H1. [img]:oops:[/img]

Back to trailers none of this has anything to do with the fact that the independents are a better idea on a trailer.
Land rovers are coil and 2 link as well.
So stock vs. stock leaf springs do not compare to independants
....All I ever sed
Look I'm not a Huimmer fan. In fact I own several Jeeps ALL WITH LEAF SPRINGS. All highly modded . It's one of my passions . If we want to talk about Tow rig suspensions lets do it somewhere else. So we don't get acused of hijacking this post . Lets get back to trailers..... ....Boxcar...

[eamarquardt]

As Mark Twain said: "If you don't read the newspaper, you are illinformed. If you do read the newspaper, you are misinformed".

Just because it is published doen't mean it's so!

My favorite (reference cited on the forum) was a summary of the most congested freeways in the country. Included was the Ronald Reagan Fwy (118) at Kuhner Ave, in Oxnard. The freeway ends 25 miles from Oxnard, the Kuhner Ave intersection is in Simi Valley (30 miles from Oxnard), and this section of freeway (based upon my almost 30 years of driving it on a daily basis) is rarely congested for more than a few minutes each day.

As I recall the 405 and 5 freeways, which are nightmares on daily basis, were not mentioned at all!

Cheers,

Gus

[boxcar]

I took Gus's advise and looked at the article in question.The articulation test was static (non moving rigs) a ramp test . Gee nothing brakes when it's siting still.....Ramp tests have nothing to do with ride and are a rather dubious test at best...
And these knuckle heads listed (and I quote )as the best offroad rigs in order
#1 Range Rover
#2M-B G 55 (Mersades)
#3Nissan Tightan (independent front suspension)
#4Lexas GX 470 ( independent front suspension)
#5Wrangler Rubicon
#6 H2 (IFS)
#7 H1 U (f&r IS)
How many of us will agree that a Newer Range Rover, Or a Mersades G-55 or a Full size pick up truck like the Tightan or the Lexas Is a better trail rig than a Jeep Wrangler. I have yet to se any of these rigs out in the bogs. While all fine rigs lets not get carried away here . Truck Trends have never ben the go to guys when it comes to Off road facts.....Try JP mag or OFF ROAD Or any of a number of mags that truly are interested in real time off road rigs!!!! Boxcar...