Air Shocks - Mystery Solved.

[bbaxter51]

Whenever you mention air shocks of any flavor to the off road masses you generally get curled up noses, their opinions on why they suck and questioned as to why you didn't just buy coils in the first place or stick with a well designed leaf sprung setup. Well it's a decision that only needs one opinion that matters; yours.

The main argument you hear from people is that air shocks fade, unload, hard to tune and are generally frustrating. That comes from 3 types of people; first is a person who has never actually run them and like to parrot what they've heard. Two, the person who never took the time to educate themselves and take the time to tune them to their rig. Three, the guy who has a bad link design in the first place and no shock will cure that.

First; there's nothing wrong any suspensions you choose to build your rig with, as long as it's designed correctly in the first place and well thought out for the how you plan to wheel. I'm going to go into a little more detail on why I personally chose air's over everything else and how to tune them so they perform as advertised. Here we go...

1. Choice. There's 4 main players in the suspension world these days and they are leaf springs, coils, air shocks, and coil over shocks. All have their strong suits and drawbacks, but today we're talking air shocks. For me and the terrain I wheeled in the Northern Midwest air shocks provided the best value. Meaning I get 90% of the benefits of coil overs at 40-50% of the price.

2. Size / Brand. There's a relatively small number of choices for air shock manufacturers. Do your homework on these. They all offer the same size in stroke generally ranging from 12", 14", 16" and 18" and a body size of either a 2.0" or a 2.5". Here's where the devil lies in the details and for that my e-friends is shaft size. Here's an example for you in case I haven't lost you yet. I'll compare 2 major shocks..
Fox 2.0" air shocks have a shaft size of 1.25" and will hold 500lbs per corner of your rig.
Sway-A-Way 2.0" air's have a shaft size of 1.375" and will hold 1000lbs per corner of your rig.

3. Keep up. The obvious difference in those 2 choices is the SAW's will handle a heavier rig; but the less obvious detail is the night and day difference in the smoothness of ride of the larger shaft on a lighter rig. Where you might max out the weight capabilities on a Fox, might be in the sweet spot for a SAW or Ballistic 2.0 air shock. This performance and shaft size also come at a cost of about $40-80 more per shock.

4. How they work. Air shocks are fairly simple; you've got a shaft with a shims on it, sliding up and down the body through oil and compressed nitrogen. The amount of oil in the shock and the shim stack are what control the compression and rebound, and the nitrogen controls the ride height. Once you break it down into 2 separate areas, it's easier to wrap your head around how to do what you want. The more oil you add, the less N2 you'll need to achieve your desired ride height. The less oil you run, the more N2 you'll need. Got it? Good.

This was a REAL basic explanation of airs and what makes them work. Stick around, i'll show you I tuned mine with pics. Any questions so far? Post up. Did I loose you at step one, tell me and I'll go into more detail on any/all of it.

 

[cgm147]

ill be watching!! good info so far

 

[Ron]

So, what makes you the expert?

 

[bbaxter51]

We're back with part 2. This time we're talking about how to tune a set of air shocks. I'll start by saying that the shocks come setup with a consistent, median amount of oil in them. Although you can fill them with Nitrogen out of the box and run them, you're kidding yourself if you think you'll have great results. Although they worked great for the guy with a 2 seat tube buggy with Toyota axles doesn't mean they'll work remotely favorable on your full bodied rig; or vice-versa. Make sense when I lay it out like that? I'll use myself as an experienced example.

I got very frustrated trying to track down anyone that would give me more than a vague answer as to what numbers others were running their airs. The fact is, unless EVERY aspect of your rig is the same and you've got the same taste in ride quality, your numbers will be different; so, here's how to tune yours.

1. Fill your shocks with N2 and run them with the stock oil levels. I know, I know; i just told you to tune them. But, you need a baseline of what you like. Are they too soft? You have too much body roll? Too stiff? Compress / rebound too fast, slow? You'll need to know where to start, if you're going to have a clue as to where you need to go.

2. Pay attention. The first time out, you're going to be amped up and think they work sweet, but they'll get better, trust me. Notice when they try to "unload" on you, put your rig in some off camber situations and see if you get more body roll then you're comfortable with. Basically just pay attention to some of the handling details.

3. Now that you've run your shocks once, write down what you'd like changed about the handling characteristics. For me, my rig rode like a Cadillac on a cloud across the field, but once I got to the off camber portion of the trail, I had more body roll than I wanted. I also noticed that on large hits, they would bottom out quite easily which ended up in some pretty harsh hits.

4. Now that you've got a baseline of where you are and know where you want to go, here's how you get there. For me, I knew my body roll was too much and I bottomed out too easily. The rig rode really nice, but I don't wheel fields at 40mph, so I was more than willing to give up a bit of that soft cushy ride to have better handling on the trails. Since now we all know that oil controls the dampening and rebound, that's where we'll start the tuning process.

5. The way you add or subtract oil is through the schrader valve after the N2 is released. I used a 11/32" socket and unscrewed the valve from the body of the shock and dumped all the stock oil out.

6. After some close calculations and lots reading the SAW website, I decided that 20ml of oil to the stock fill level of each shock would get me closer to where I wanted to be. You NEED to do this research and find out some key info from your particular shock manufacturer. Stock oil level, min oil level and max oil level. If you over fill your shock with oil, it will hydro lock and possibly do some real expensive damage. So when you add your oil, make sure you do with the shock fully compressed. This will ensure you're not hydro locking the shock.

7. So now you've got the custom oil levels in each shock, the next step is adding the N2 back into them. Now that you've messed with your oil levels, the Nitrogen levels will also need to be adjusted. This one is easier since we all know that N2 only controls the ride height and nothing else, right? exactly. As the oil level goes up in the shock, the N2 levels will go down to get the same amount of ride height mounted in the rig. Opposite is true if you took oil out, it will take more N2 to get to the same ride height you had with less oil in the shocks.

Let's back up for a second. Although I added 20ml of oil to my shock, I'm here to tell you that 5ml of oil will effect performance once way or another, 10ml will be a very noticeable difference. Don't be afraid to play with your shocks, spend some time tuning them, customize them individually and your effort will pay off in spades.

How did mine perform after some tests and tuning sessions? It's like wheeling a completely different rig. My body roll is all but gone, I'm stable on off camber runs, the ride is definitely firmer, but still very comfortable. My articulation is insane and bottoming out on hard hits are a thing of the past. In the end, I gave up about 1" in up travel and gained stability that will rival a set of leafs. For those of you still not convinced, I'm doing all this without a sway bar on either end. Are air shocks the best thing ever? Nope. But they're pretty damn good. Got any questions? Let's hear em' and we'll talk it out.

If you think a set of air shocks are for you, great. I do want to be very clear about one thing. You must have a properly designed and setup link suspension for shocks to work well for you. There's more information about link geometry out there, then a person could ever want to read. Still fuzzy on that topic, check out my writeup on link setup and design.

 

[bbaxter51]

So, what makes you the expert?

No expert by any means, just sharing info I thought would have been helpful when I was buying and tuning mine. If you've got info to share for those just getting started, please post up. Especially if you think I've posted miss information.

 

[Copasetic]

Good read! My Samurai is in the final stages of having the leaves taken out and a 4 link front and rear with Fox 2.0's at each corner. I can't wait to get it back on the trails. This info is going to be useful for me for sure.

 

[GubNi]

I ran air shocks on the rear of my buggy. I upgraded from coil springs and it was an awesome upgrade. The only problem I see is when people run them on all 4 corners and it flops from side to side too each.

 

[Stuntman Autoworks]

Subscribed! Good info deffinately an interesting read

 

[BRUISER]

I run 2.5 SAW on my XJ and they are awesome and very smooth and stable..

 

[RenegadeT]

I run 2.5 SAW on my XJ and they are awesome and very smooth and stable..

is this the stable XJ that rolled at DPG?

 

[Hurley]

unsolicited write-ups make everyone go

 

[bbaxter51]

I've got a handful of tech articles I wrote for our clubs forum from years of trial and error.
Leaf spring tech - how to properly setup a left sprung rig.
Full Hydro setup tech.
Taking the mystery out of air shocks - how to tune them.
How to twin-stick a 205 for free.
Anyone interested in this crap other than me? Let me know and I'll copy them over here too.

Absolutely. If any of them have photos and are (somewhat) polished, we could put them on the front page, too.

i would be intrested.

unsolicited write-ups make everyone go

Unsolicited? It's in the Newbie section. Have any tech to add to help out guys who don't already have it all figured out?

 

[Ron]

No expert by any means, just sharing info I thought would have been helpful when I was buying and tuning mine. If you've got info to share for those just getting started, please post up. Especially if you think I've posted miss information.

Maybe my post came across wrong. I was not intending to slam you or your post, rather my point was to say that if you would star by sharing a bit of your background and how you came to your conclusions a reader would be more interested. When you speak(or write) in an exaggerated authoritative tone people miss much of the message trying to determine the sources credentials. Eliminate the confusion by stating the credentials at the front end.

That is all, and thnaks for the contributions to the community

 

[Hurley]

Unsolicited? It's in the Newbie section. Have any tech to add to help out guys who don't already have it all figured out?

Ron's post above explains the issue better:
"When you speak(or write) in an exaggerated authoritative tone people miss much of the message trying to determine the sources credentials."


Most newbie threads fit the Q&A format, and this thread did not, so here we are.

 

[bbaxter51]

Maybe my post came across wrong. I was not intending to slam you or your post, rather my point was to say that if you would star by sharing a bit of your background and how you came to your conclusions a reader would be more interested. When you speak(or write) in an exaggerated authoritative tone people miss much of the message trying to determine the sources credentials. Eliminate the confusion by stating the credentials at the front end.
That is all, and thnaks for the contributions to the community

Completely understandable. The few "tech" articles I wrote were written a couple years ago for the guys in my club back in MN so we all knew each other personally, very well so I can see how the tone of how I wrote them would seem a little authoritative to complete strangers.

As for my background: I grew up wheeling with my dad and got my first rig back in 94. Been building and learning every step of the way since. I haven't met anyone in the wheeling community I haven't learned something from, so these articles were a way I could try to give back to those new to the sport, since back in the Midwest there's a fair share of guys that like to hold knowledge and look down on those that don't know as much. Not me, If I can help, I'm going to do it.

I was also pretty heavy into the land use issue back in MN and hope to get involved down here as well as much as time allows. If you ever read CRAWL mag, I wrote an article in issue 30 about trails getting built in MN.
http://www.crawlmag.com/archives/1803

I'm not a writer, pro, racer, sponsored or anything fancy like that. Just a MN guy transplanted here in the south trying to help if/where I can.

*hurley*
"Most newbie threads fit the Q&A format, and this thread did not, so here we are. "

Ask away, If I don't know the answer, I'll be the first to tell you.

 

[Yay!Gurrr]

Great info !

 

[upnover]

it's helping me as in the future I plan on a 4 link set up, but unsure of what shock to use. Been leaning toward toe ORI's, but not set in stone. Thanks for taking the time to educate

 

[MetalCraftSolved]

Meaning I get 90% of the benefits of coil overs at 40-50% of the price.

Excluding ORI's, I'd say that typical air shocks give you a significantly smaller percentage of benefits compared to a coil-over.
For a quick example without getting into detail.... You lose the possibility of running a remote reservoir which means you have no consistency when tuning and you lose your easily exchangeable dual rate or triple rate spring zones.

 

[shawn]

Excluding ORI's, I'd say that typical air shocks give you a significantly smaller percentage of benefits compared to a coil-over.
For a quick example without getting into detail.... You lose the possibility of running a remote reservoir which means you have no consistency when tuning and you lose your easily exchangeable dual rate or triple rate spring zones.

Yeah, maybe we should step back and talk about that for a minute. What air shocks have going for them is they're cheap, they package easily, you can get as much travel out of them as you need, but the 'spring rate' is fairly linear (making them prone to unloading) and they're not well-suited to racing applications (can only dissipate so much heat, so they fade and get 'tall' from gas expansion). ORIs are position-sensitive, so unloading is a bit less of an issue there.

What else?

 

[braxton357]

What I hate most about air shocks is the "sticking" in position...as in going around a corner or off camber and having one side of the rig stay jacked up afterwards. And the fact that you can't really tune only one characteristic at a time. Like was said, pretty much the only thing that they have going for them is that they're cheap and easy to package...there's a reason why no one uses them anymore, at least in standard form. Have you tried using different oil weights yet?

 

[bbaxter51]

What I hate most about air shocks is the "sticking" in position...as in going around a corner or off camber and having one side of the rig stay jacked up afterwards. And the fact that you can't really tune only one characteristic at a time. Like was said, pretty much the only thing that they have going for them is that they're cheap and easy to package...there's a reason why no one uses them anymore, at least in standard form. Have you tried using different oil weights yet?

In the rigs I've setup and wheeled with, the shocks only "stick" when they're new, after 3-4 trips out, they don't stick anymore. The side hill / off camber and the rig flops over to the side and stays there seems like bad link geometry rather then an issue of air shocks. At least it has been in the 2 guys in our crew that had that issue. Once the link setup was re-done, it wasn't an issue anymore. Different weight oil is a nice easy way to start a tune before you tear into the shim stacks.

To me, comparing an air shock to a dual or triple rate coil-over over is like comparing a set of stickies to a set of iroks or pbr's. One is better suited for comps and racing, the other is just fine for the rest of us wheeling on the weekends on a budget.

 

[jaybird1ton]

The set up on your 4 link is VERY important and has a tremendous affect on your performance as has been said. You can fix a little of it with a sway bar if their are not many options in redoing your link set up. I loved my air shocks but on my new rig I have coil overs and 1 major advantage is if ya blow a shock your still riding on your coils. This thread is very helpful! Good info!