What are the real variables that control and influence ride quality?

[Irun]

This post is a quest for knowledge, as much as it is about getting the ride I want. I've spent a significant amount of time reading through threads on everything from tire pressure, tire load rating, springs, shocks, control arms, weight, etc. Although I've seen bits and pieces, finding a compiled list of items, that when done, have an effect (see definition below) ride quality, and what doesn't, is difficult. Especially, given the way threads tend to devolve. I even read through this thread, which gave some information, with one item (Tire Load Rating) conflicting with other information.

https://wranglertjforum.com/threads/how-can-i-fix-a-harsh-ride-on-my-jeep-wrangler-tj.16558/
That said, the goal here is to put together a concise list that I'll update in the original post. Although I don't expect to get it right up front, I'm confident you all will ultimately help define/refine it. Perhaps, later, this could be appended to the list Chris started. For further clarity, we're talking about the "effect" of changes made, i.e. the noun

’Effect’ as a Noun​

As a noun, an effect is "a change that results when something is done or happens," or "a particular feeling or mood created by something."

Lastly, we should differentiate between two particular topics. For the purposes of this thread, the latter, "quality" is our focus here. Specifically, the "standard" that should be measured against is a new (let's say broken in) stock Jeep. With that in mind, anything we do to them should at least maintain the stock level of ride "quality" or, preferably, improve it. To be clear, I'm not saying the factory ride was ideal, but that a reference is needed.

1. com·fort [ˈkəmfərt]
NOUN
a state of physical ease and freedom from pain or constraint:
"room for four people to travel in comfort"

2. qual·i·ty [ˈkwälədē]
NOUN
the standard of something as measured against other things of a similar kind; the degree of excellence of something:
"an improvement in product quality" ·

Lets start the list!

(Insert word/s below) has no effect on ride quality: Example - "A spring change has no effect on ride quality."
- A spring change (Assuming springs made for this platform are fairly close in rates)
- A control arm/joint
- The arm angles (Up to 5" lift)
- The tire load rating
- The wheel size (Assuming wheels in the 15" to 17" range)

(Insert word/s below) has an effect on ride quality: Example - "Road surface conditions has no effect on ride quality."
- Shocks, shocks, shocks
- Road surface conditions
- Tire pressure
- Tire balancing
- Sprung weight (Assuming shocks aren't adjusted accordingly)
- Un-sprung weight

 

[Wtrask]

you would be surprised at how much spring rates vary between manufacturer and oem for different models. The info is out there just have to search for it. I’ve pretty much exhausted my search for a softer ride. Black maxes and Currie springs are where I’m at now.

 

[mrblaine]

What does impact ride quality:
- Shocks
- Tire pressure
- Tire balancing
- Sprung weight (Assuming shocks aren't adjusted accordingly)

The first thing that impacts ride quality is road surface conditions.
I don't care about tire pressure or tire weight ratings or anything to do with tires except that they hold air, are well balanced, and run smoothly.

Sprung weight can be dealt with, most important thing is not to ignore it and expect your empty cargo area soft top no spare tire having TJ will respond the same as a fully laden TJ Unlimited.

 

[mrblaine]

you would be surprised at how much spring rates vary between manufacturer and oem for different models. The info is out there just have to search for it. I’ve pretty much exhausted my search for a softer ride. Black maxes and Currie springs are where I’m at now.

They actually can't vary that much for similar lift heights.

 

[SSTJ]

I have two Jeeps (A TJ and LJ) that run the same shocks, but the overall ride is dramatically different. Because of that, this post is a quest for knowledge, as much as it is about getting the ride I want. I've spent a significant amount of time reading through threads on everything from tire pressure, tire load rating, springs, shocks, control arms, weight, etc. Although I've seen bits and pieces, finding a compiled list of what truly impacts ride quality, and what doesn't, is difficult. Especially, given the way threads tend to devolve. I even read through this thread, which gave some information, with one item (Tire Load Rating) conflicting with other information.

https://wranglertjforum.com/threads/how-can-i-fix-a-harsh-ride-on-my-jeep-wrangler-tj.16558/
That said, the goal here is to put together a concise list that I'll update in the original post. Although I don't expect to get it right up front, I'm confident you all will ultimately help define/refine it. Perhaps, later, this could be appended to the list Chris started.

What doesn't impact ride quality:
- Springs (Assuming springs made for this platform are fairly close in rates)
- Control arms/joints
- Arm angles (Up to 5" lift)
- Tire load rating
- Rim Size (Assuming rims in the 15" to 17" range)

What does impact ride quality:
- Road surface conditions
- Shocks
- Tire pressure
- Tire balancing
- Sprung weight (Assuming shocks aren't adjusted accordingly)

In addition to the shocks themselves, how about "up travel : down travel ratio"?

 

[SSTJ]

Also, what about adding a brief explanation as a sub-point for each item in the list? For instance, I'd be eager to hear why the load rating is on the "doesn't impact" list, since I've read so many times on here that it has an impact.

And maybe, just to avoid quibbles over technicalities, the "doesn't impact" list should be called something like "minimal impact", or "diminishing returns", or "don't bother".

 

[AndyG]

Glad you started this thread- will be watching to learn

My 06 with a 4” lift and load range E KO2 tires exceeds my 03 with a 4” lift and load range C tires-

 

[Mike_H]

Glad you started this thread- will be watching to learn

My 06 with a 4” lift and load range E KO2 tires exceeds my 03 with a 4” lift and load range C tires-

Exceeds how? In good ride quality or harshness, or...

Don't forget wheelbase. @Irun, you're kinda comparing apples to oranges if you're looking for the differences between the TJ and the LJ. I also think relative age of the suspension components plays a hand in this. You probably can't id one thing, but the sum of the whole contributes mightily. In other words, your TJ is all brand new underneath, and the LJ still has old stuff under it.


For my own personal experience, the only thing that has made an appreciable, noticable change in how my TJ rides has been shocks.

 

[AndyG]

Exceeds how? In good ride quality or harshness, or...

Don't forget wheelbase. @Irun, you're kinda comparing apples to oranges if you're looking for the differences between the TJ and the LJ. I also think relative age of the suspension components plays a hand in this. You probably can't id one thing, but the sum of the whole contributes mightily. In other words, your TJ is all brand new underneath, and the LJ still has old stuff under it.

Thanks for clarifying Mike- the 06 with E range and Rough Country shocks rides considerably better than the 03 with Rancho Shocks and C range tires-

 

[mrblaine]

Also, what about adding a brief explanation as a sub-point for each item in the list? For instance, I'd be eager to hear why the load rating is on the "doesn't impact" list, since I've read so many times on here that it has an impact.

And maybe, just to avoid quibbles over technicalities, the "doesn't impact" list should be called something like "minimal impact", or "diminishing returns", or "don't bother".

I've played with several JK tire and rim take-offs. Same size tire, same rim, the MT rides like dog shit, the street tire is one of the best riding tires I've ever driven on. It isn't as simple as load range.

 

[Irun]

Exceeds how? In good ride quality or harshness, or...

Don't forget wheelbase. @Irun, you're kinda comparing apples to oranges if you're looking for the differences between the TJ and the LJ. I also think relative age of the suspension components plays a hand in this. You probably can't id one thing, but the sum of the whole contributes mightily. In other words, your TJ is all brand new underneath, and the LJ still has old stuff under it.

I get the wheelbase and weight difference between the two platforms. Also, the sentence in red is really what I'm poking at a little here. Through all the threads I looked at there were references to specific things, but very little about a more holistic balance.

I've played with several JK tire and rim take-offs. Same size tire, same rim, the MT rides like dog shit, the street tire is one of the best riding tires I've ever driven on. It isn't as simple as load range.

It makes perfect sense, but doesn't get a lot of press. When I ran the A/T tires the ride was very good. Not great, but still acceptable to me. When I recently switched to a set of M/T tires, "C" rated and at 26 PSI, the ride became noticeably worse. Truthfully, I hadn't really thought about that until you brought it up. It's a factor, in a group of factors.

 

[jjvw]

you would be surprised at how much spring rates vary between manufacturer and oem for different models. The info is out there just have to search for it. ...

In the resources section we have a very large list of springs with their rates and lengths. There isn't very much variation. And there is less so when you compare similar lift heights.

 

[freedom_in_4low]

when it comes to TJ vs LJ riding differently with otherwise identical suspensions and loads, I believe that the rear axle being further from the vehicle center of mass causes there to be significantly less weight on the rear axle, so a shock that worked well under a TJ will have an LJ overdamped in the rear.

 

[jjvw]

Also, what about adding a brief explanation as a sub-point for each item in the list? For instance, I'd be eager to hear why the load rating is on the "doesn't impact" list, since I've read so many times on here that it has an impact.

And maybe, just to avoid quibbles over technicalities, the "doesn't impact" list should be called something like "minimal impact", or "diminishing returns", or "don't bother".

Anecdotal on my part, but I have run several sets of E And C rated tires. I never thought that my Es rode hard. One set of C's rode the same as the Es. And my current set of C's are slightly softer than the Es were. I think this falls into the don't bother category because there are far too many differences between different tires to determine the ride based solely on the load rating.

 

[Blackjack]

Unsprung weight needs to be added to the can change ride list. 20 pounds per corner tire and wheel weight difference can be felt.

 

[jjvw]

... I also think relative age of the suspension components plays a hand in this. You probably can't id one thing, but the sum of the whole contributes mightily. In other words, your TJ is all brand new underneath, and the LJ still has old stuff under it.

...

What if I were to tell you that a loose exhaust that is knocking and flopping around will negatively impact the ride quality?

....


For my own personal experience, the only thing that has made an appreciable, noticable change in how my TJ rides has been shocks.

Very much agree. I have experienced this several times on mine.

 

[psrivats]

@Irun I know you want to mostly discuss the mechanical aspects of things here, but the overall noise level inside the cabin absolutely matters to the perception of ride quality. Suspension parts rattles/squeaks, tire shimmy/wobbles, tire/road noise, drive line vibrations, soft top flapping at speed, loose steering etc will assault our senses in different ways and add negatively the "ride quality" bucket.

@mrblaine already partly hinted at this by sharing his observation about road vs mud tires.

 

[TheBoogieman]

@Irun I know you want to mostly discuss the mechanical aspects of things here, but the overall noise level inside the cabin absolutely matters to the perception of ride quality. Suspension parts rattles/squeaks, tire shimmy/wobbles, tire/road noise, drive line vibrations, soft top flapping at speed etc will assault our senses in different ways and add negatively the "ride quality" bucket.

A wife cancels out all those other "assaults on our senses". I just took a 2 hour road trip with my Jeep and wife. She didn't stop talking the entire time. I was actually thinking of leaving her at the gas station when I filled up.

 

[freedom_in_4low]

The driver window in my hardtop was loose in the seal, so bumps made it rattle in the frame. It started rattling a lot more when I ditched my KO2's for Cooper STT Pro, giving me the perception that the Coopers rode much rougher. Once I sold the hardtop, the noise was gone and now the ride seems just fine. I'm even more used to the RS5000x being stiffer in the rear of the LJ, enough so that I'm less motivated to try out other shocks than I was a few months ago.

 

[srimes]

A wife cancels out all those other "assaults on our senses". I just took a 2 hour road trip with my Jeep and wife. She didn't stop talking the entire time. I was actually thinking of leaving her at the gas station when I filled up.

How did you make your jeep quiet enough to hear her?