Independent Suspension vs Solid Rear Axle??

[CrazyOldMan]

The issue for manufacturers is that there is a ton of data showing that the average person in these segments (the two biggest in the US) doesn't take their vehicle off-road. Or if they do, it is fireroads and light-obstacle kinds of stuff that isn't too stressful or dangerous/damaging - especially when you need that vehicle as a daily driver. So it gets difficult to justify the crappy ride of a solid front axle in a half-ton truck for the 2% of the market that want it, versus the rest of the market that wants their truck to ride and handle well. We are building a capable, rugged truck, and it will be able to take you to 95% of the places most people would want to go. Beyond that, you might have to add a lift kit and some mods for specialized use. I've been to Moab numerous times, and any vehicle with decent approach and departure angles and locking diffs can do most things out there. Heck, we took a first-generation Touareg in and out of Micky's Hot Tub. Guys with $30k in mods on their Jeeps were just shaking their heads.

We have some deep off-road enthusiasts employed at Scout with some serious rigs. We have had major aftermarket companies out to our engineering and design office in Michigan. The vehicle itself is body-on-frame and can handle a lift kit. The bumpers are designed to be removable. Front and rear locking diffs are available, and a front sway bar disconnect. We expect some robust aftermarket support down the road. I know some of you would love a solid front axle, but the tradeoff in ride and handling was too much.

Can I also say “BRAVO” on the bumper design? This is a big issue with the GX 550. Being able to swap for aftermarket without cutting is important - clearly you guys have thought that out. Just making consistently smart choices. Really, really impressed.

 

[chucchinchilla]

there is a ton of data showing that the average person in these segments (the two biggest in the US) doesn't take their vehicle off-road. Or if they do, it is fireroads and light-obstacle kinds of stuff that isn't too stressful or dangerous/damaging - especially when you need that vehicle as a daily driver.

 

[CrazyOldMan]

Strong (possibly overkill) tie rods and some heavy duty half shafts with good shaft/joint angles and you can prevent most issues. I agree though, IFS is inherently weaker and a locker highlights that more. The “POP” is indeed common but when well designed from the factory, it’s less and less of an issues these days. Lifts change your half shaft angles and put more stress on those joints, bigger tires and lower gearing puts more stress on everything. That’s the common cause of the pops.

The minor tradeoffs of IFS are worth it for most vehicles these days.

To prove your point - there are a number of failed front drive shafts (at the boot) on the Grenadier when lifted. Failures aren’t on the wheel hub assembly, but the front of the drive shaft where the boot gets pinched with a tighter angle. So it’s not as vulnerable in the same way - but it’s another point of vulnerability and a good example of what happens when you mess with geometry.

 

[R1TVT]

Strong (possibly overkill) tie rods and some heavy duty half shafts with good shaft/joint angles and you can prevent most issues. I agree though, IFS is inherently weaker and a locker highlights that more.

I would say this is where Rivian has had to invest time & spend more $$$ in their services centers - addressing issues with the joints and half-shafts wearing prematurely or creaking and creating gremlins. Why? There is a great amount of travel and ride height adjustment (with air) that can be the cause of additional stress at the joints. Creating the balance between driveability, performance, cost and comfort is tricky with these modern suspension designs. It is certainly better to bust a tie-rod or replace a worn shaft, than to take out an entire drive unit (or something much more costly). I'm guessing Scout understands all of this when it comes down to the final production design of the entire suspension system given the expertise of the staff that Jamie has pointed to.

 

[CRobin]

Can you explain how a solid axle leads to better articulation? That seems counterintuitive, given that it seems like there would be fewer constraints on an independent system. I understand the fulcrum bit, that makes more sense to me but I’m confused by the articulation thing.

I was going to ask the same thing. But I love all these answers so far! Thank you ALL for explaining!

 

[CRobin]

You also get into discussions about which part should be the weak link. Do you want to break expensive and difficult-to-repair stuff? Or cheaper/easier to repair items?

To your earlier point, the set up is indeed IFS and a rear solid axle with coil springs? Or leaf springs?

 

[CRobin]

I would say this is where Rivian has had to invest time & spend more $$$ in their services centers - addressing issues with the joints and half-shafts wearing prematurely or creaking and creating gremlins. Why? There is a great amount of travel and ride height adjustment (with air) that can be the cause of additional stress at the joints. Creating the balance between driveability, performance, cost and comfort is tricky with these modern suspension designs. It is certainly better to bust a tie-rod or replace a worn shaft, than to take out an entire drive unit (or something much more costly). I'm guessing Scout understands all of this when it comes down to the final production design of the entire suspension system given the expertise of the staff that Jamie has pointed to.

Right! and makes you wonder why Rivian stayed with the most expensive way to set up with Air suspension???? Out here you can't even see a Rivian less than $107,000. and that is the for one of the lowest trims. SMH. I am sure the other suspension options are far cheaper than an expensive air suspension set up no???

 

[R1TVT]

Right! and makes you wonder why Rivian stayed with the most expensive way to set up with Air suspension

All trade-offs...

Ride Comfort / Durability
On-Road / Off-Road
Height Adjustments / Static height
Camp Mode Levelling / Piling up rocks under one wheel

Etc,. etc, etc,

I think the main reason why they stuck with it is because on road ride quality is really good with air AND you can take advantage of the side-country stuff like levelling for camping. Because it is very difficult to mod a Rivian and they are pricey, there are better rock-crawlers with solid axles to go roll boulders with.

 

[socalscout]

Solid axles and multi link suspension for the win.

IFS is for minivans and sedans

 

[CrazyOldMan]

Solid axles and multi link suspension for the win.

IFS is for minivans and sedans

Depends on what game you’re trying to win. Solid axle (both) means only 2 options: Jeep Wrangler/Gladiator (a fantastic technical trail and rock crawling specialist) and Grenadier/Quartermaster (expedition overlanding and zombie apocalypse). Or a heavy duty truck. Actually neither the best as a high speed offroad runner. Are either fantastic with road manners and broad, multi-use scenarios? Probably not. Are either going to be the best choice for a big part of the market that just wants to get out and have fun on dirt without having to think too much about it? Probably not. And I’m a loyal and happy Grenadier owner. I still have a ton of respect for the Outback, and new Defender, and many others. All have their strengths and weaknesses, and meet the needs of different people for different uses. And for some people and places, the solid axle just really doesn’t have a chance to shine. “Green laning” in the UK? The Defender will definitely win that game against the Grenadier - there just aren’t many situations where you can use it as intended. Everything I’ve seen on the Scout so far impresses me. It’s a rational approach to EV, will probably deliver more capability than most options, will probably be pleasant and comfortable to drive, will be easy to modify, and looks great. I hope they keep going and are wildly successful- I think they will be. I would like to add one to my garage. Or rather, I would like to convince my wife that SHE should add one to our garage (because then it’s considerate and thoughtful and not just me being stupid).

 

[CRobin]

All trade-offs...

Ride Comfort / Durability
On-Road / Off-Road
Height Adjustments / Static height
Camp Mode Levelling / Piling up rocks under one wheel

Etc,. etc, etc,

I think the main reason why they stuck with it is because on road ride quality is really good with air AND you can take advantage of the side-country stuff like levelling for camping. Because it is very difficult to mod a Rivian and they are pricey, there are better rock-crawlers with solid axles to go roll boulders with.

I get it. They just cost way too much. I really hope Scout can keep their pricing where they say they are going to start.

 

[CRobin]

Depends on what game you’re trying to win. Solid axle (both) means only 2 options: Jeep Wrangler/Gladiator (a fantastic technical trail and rock crawling specialist) and Grenadier/Quartermaster (expedition overlanding and zombie apocalypse). Or a heavy duty truck. Actually neither the best as a high speed offroad runner. Are either fantastic with road manners and broad, multi-use scenarios? Probably not. Are either going to be the best choice for a big part of the market that just wants to get out and have fun on dirt without having to think too much about it? Probably not. And I’m a loyal and happy Grenadier owner. I still have a ton of respect for the Outback, and new Defender, and many others. All have their strengths and weaknesses, and meet the needs of different people for different uses. And for some people and places, the solid axle just really doesn’t have a chance to shine. “Green laning” in the UK? The Defender will definitely win that game against the Grenadier - there just aren’t many situations where you can use it as intended. Everything I’ve seen on the Scout so far impresses me. It’s a rational approach to EV, will probably deliver more capability than most options, will probably be pleasant and comfortable to drive, will be easy to modify, and looks great. I hope they keep going and are wildly successful- I think they will be. I would like to add one to my garage. Or rather, I would like to convince my wife that SHE should add one to our garage (because then it’s considerate and thoughtful and not just me being stupid).

Hahahaha same. SHE should get the SUV SHE wants. Then I have a reason to get the truck too. Or get both!

 

[J. Sweat]

The bumpers are designed to be removable. Front and rear locking diffs are available, and a front sway bar disconnect.

All I needed to know, thanks!

 

[Hedrock]

We have some deep off-road enthusiasts employed at Scout with some serious rigs. We have had major aftermarket companies out to our engineering and design office in Michigan. The vehicle itself is body-on-frame and can handle a lift kit. The bumpers are designed to be removable. Front and rear locking diffs are available, and a front sway bar disconnect. We expect some robust aftermarket support down the road. I know some of you would love a solid front axle, but the tradeoff in ride and handling was too much.

Also, while you certainly haven’t confirmed anything and I’m sure it’s subject to change, “can handle a lift kit” sounds to me like no air struts à la Rivian.

 

[cyure]

View attachment 10389

Also, while you certainly haven’t confirmed anything and I’m sure it’s subject to change, “can handle a lift kit” sounds to me like no air struts à la Rivian.

Is an air air strut air suspension, because if so I thought they had said that would be an option.

 

[Hedrock]

Is an air air strut air suspension, because if so I thought they had said that would be an option.

I remember a lot talk about it but not an actual confirmation…

But what I meant to say was, *For the offroad package*. Maybe one of our engineering minded folks could chime in but my understanding was full air strut vehicles (not the airbags like the Aussie use) aren’t conducive to coilover conversions and that sort of lift kit.

 

[cyure]

I remember a lot talk about it but not an actual confirmation…

But what I meant to say was, *For the offroad package*. Maybe one of our engineering minded folks could chime in but my understanding was full air strut vehicles (not the airbags like the Aussie use) aren’t conducive to coilover conversions and that sort of lift kit.

I did ask at Nats if the Traveler was lifted on the 35s. I was told not lifted but an “off road setup”. Whatever that means.

I’m already picturing the forum when we actually get facts. It’s going to be crazy.

 

[Iguy]

I remember a lot talk about it but not an actual confirmation…

But what I meant to say was, *For the offroad package*. Maybe one of our engineering minded folks could chime in but my understanding was full air strut vehicles (not the airbags like the Aussie use) aren’t conducive to coilover conversions and that sort of lift kit.

They have said air and steel (coil spring) options. I’m personally wanting steel for a couple reasons, but mostly simplicity.

As for lifting, it depends. You can add spacers to either for a lift, but with steel springs you can change coils and shocks/struts for a lift with a lot more customization and potential for increased travel. The bigger issue for lift kits with independent suspensions we already touched on. You typically need subframe spacers and it screws up driveline angles.

So basically I agree, air isn’t as conducive to lifts as other options.

 

[THil08]

The issue for manufacturers is that there is a ton of data showing that the average person in these segments (the two biggest in the US) doesn't take their vehicle off-road. Or if they do, it is fireroads and light-obstacle kinds of stuff that isn't too stressful or dangerous/damaging - especially when you need that vehicle as a daily driver. So it gets difficult to justify the crappy ride of a solid front axle in a half-ton truck for the 2% of the market that want it, versus the rest of the market that wants their truck to ride and handle well. We are building a capable, rugged truck, and it will be able to take you to 95% of the places most people would want to go. Beyond that, you might have to add a lift kit and some mods for specialized use. I've been to Moab numerous times, and any vehicle with decent approach and departure angles and locking diffs can do most things out there. Heck, we took a first-generation Touareg in and out of Micky's Hot Tub. Guys with $30k in mods on their Jeeps were just shaking their heads.

We have some deep off-road enthusiasts employed at Scout with some serious rigs. We have had major aftermarket companies out to our engineering and design office in Michigan. The vehicle itself is body-on-frame and can handle a lift kit. The bumpers are designed to be removable. Front and rear locking diffs are available, and a front sway bar disconnect. We expect some robust aftermarket support down the road. I know some of you would love a solid front axle, but the tradeoff in ride and handling was too much.

Jamie it better be able to handle the Trans New Jersey Trail.

 

[6-ScoutFamily]

Jamie it better be able to handle the Trans New Jersey Trail.

And what, pray tell, is the Trans New Jersey Trail?