Airing Down - Airin Up Why/ How

[Geeper4x4]

I am looking for the experts here to tell me all about airing down and back.
I know what I do and why but I'm looking for explanations that really break it down. I go down to 10-12 when I'm out on the trail. I don't have any devices to air down except a large chuck that I use without a hose. I know they make devices to take you down to a predetermined psi. Take me to task and tell me all about it. I am willing to learn.

[fish]

http://content.costco.com/Images/Content/Product/173692.jpgjust buy the Stuan deflators, set them at your desired air down pressure screw them on your valve stems when you are ready to air down,they take the pressure down to the pre-determined psi and shut off automatically when that psi is reached. ...... simple !
air up when you are finished wheeling with a small compressor you hook to your battery and off you go.(got my deflators from northridge and my compressor from costco).
http://www.rockcrawler.com/techreports/staun_tyre_deflators/deflating_tire.jpg

[Ryno]

In response to the question, "Why?"...

Airing down provides three main benefits:

It gives you a larger footprint, i.e., it enlarges your contact patch (the tire width), but more importantly, it enlarges your tread patch (the tire length that comes into contact with the driving surface).
It allows the tires to conform to surface irregularities. When the tires can "wrap" around a rock, they provide greater shear resistance and therefore better traction.
It provides for a smoother ride. Less pressure allows the tires to absorb the bumps and transfer less movement to the suspension and cabin.

[racer83l]

In response to the question, "Why?"...

Airing down provides three main benefits:

It gives you a larger footprint, i.e., it enlarges your contact patch (the tire width), but more importantly, it enlarges your tread patch (the tire length that comes into contact with the driving surface).
It allows the tires to conform to surface irregularities. When the tires can "wrap" around a rock, they provide greater shear resistance and therefore better traction.
It provides for a smoother ride. Less pressure allows the tires to absorb the bumps and transfer less movement to the suspension and cabin.



Ryno- :thumbs: perfect explanation. couldnt have read it better in a book.

[scouter4life]

I just got the Staun deflators, can't wait to try them this weekend. Though after my last trip and how hot it was while airing back up with my small compressor, I'm thinking about getting a tank to speed things up. When it's 100+ out, it's get's really hot while waiting 20 minutes to air up the tires.

I can't add much to what was said above, they hit it perfectly with the explanations.

[scouter4life]

just buy the Stuan deflators, set them at your desired air down pressure screw them on your valve stems when you are ready to air down,they take the pressure down to the pre-determined psi and shut off automatically when that psi is reached. ...... simple !
air up when you are finished wheeling with a small compressor you hook to your battery and off you go.(got my deflators from northridge and my compressor from costco).
http://www.rockcrawler.com/techreports/staun_tyre_deflators/deflating_tire.jpg

Fish - quick question, do you leave the deflators on while on the trail or take them off after they are done? I've read you can leave them on, but they see to stick out a lot and I'm afraid they'll get damaged or ripped off by rocks.

[deanthemachine04]

also if you air down, your tires will be more resistant to getting cut from a sharp rock. i punctured one of my stockers because i left it at 35psi.

[Windshear]

So on a stock Rubicon what PSI should I air down to for rock climbing?

[jkkat]

Stauns are ok but if your looking for an easier way with a more adjustability get this.

http://www.northridge4x4.com/proddetail.php?prod=ARB-DEFLATOR

http://i243.photobucket.com/albums/ff229/JKkat/ARB-DEFLATOR-s.jpg

[jkkat]

So on a stock Rubicon what PSI should I air down to for rock climbing?

With RubyDoo loaded with whats in my signature i go to 20 with the stock wheels and tires. Less weight you can go down to 15, when i did this i kept breaking beads.

[BYU JK]

Fish - quick question, do you leave the deflators on while on the trail or take them off after they are done? I've read you can leave them on, but they see to stick out a lot and I'm afraid they'll get damaged or ripped off by rocks.

I love these and always take them off while wheeling and put the regular caps back on. Also, you will want to set your deflators before you go and a good way to do that is to air your spare down to the desired PSI and then set each of them to that PSI. It's pretty easy to set and even easier to use when you are airing down on the trail. Those are a good buy.

[scouter4life]

Thanks BYU & ******, that's what I figured, but wanted to verify.

[Kachad]

I regularly air mine down to 15 psi and haven't broken any beads yet with the stock Rubi tires\rims. I know alot of other guys that run down to 8 psi, but 15 seems to have treated me pretty well.

[07crawler]

I regularly air mine down to 15 psi and haven't broken any beads yet with the stock Rubi tires\rims. I know alot of other guys that run down to 8 psi, but 15 seems to have treated me pretty well.
I have had my stock Rubi BFG's down to 5 psi in the snow..because there is not much sidewall to flex on the BFG's 5 psi worked great and I really needed last time in the snow...rock crawling I agree that 12 to 15 is just fine

[fish]

Fish - quick question, do you leave the deflators on while on the trail or take them off after they are done? I've read you can leave them on, but they see to stick out a lot and I'm afraid they'll get damaged or ripped off by rocks.

no way do we leave them on.we have actually damaged the valve stems so bad on trips that we had to change the tire out with the spare because we were unable to air the damaged valve stem tire up.
not to mention the deflators are a bit pricey.

[RedrockX]

I have found that air up times improve if you keep the engine running when using the cheapo compressor.

Hell, i keep mine running and it still takes 8-10 min. each..!!!
sucky sucky

and my Staun deflators are supposed to be at 18 psi out of the box, but they were closer to 15, but we had no problems.

[Rub61]

Cheapo compressor from Costco works just great. Stock Rubicon tires air from 15 to 37 in 3 minutes each. Really a great little pump for 40 something dollars. :thumbsup:

[serveapurpose]

I picked up the Smittybuilt Deflators at 4WheelParts for $30 and they are identical to the Stauns that are $60. I also have the Viair 400p compressor that works fine to air up my 35's in about 2 1/2 minutes each from 15psi to 30psi.

[VBS4]

Or you can just make your own for about $30 and make sure the tires are the exact same pressure.

Here's my how-to

http://www.jk-forum.com/showthread.php?t=34126&highlight=tire+deflating

Works great:thumbsup:

[Geeper4x4]

VBS4- I do intend on making this setup for my Jeep. I read the writeup some time ago and loved the idea. Thanks for reminding me of another project.

Thanks for everyone posting. I can explain the reasoning of airing down much better than before. Sometimes it's not learning something really new but being better able to help someone understand all the reasons why something works better.

[mmcan]

I am curious,...

If you aren't having any traction issues on the terrain,...

Do you "always" air down?:thinking:

I have been letting out about 8-10 psi to the mid to high 20's, but haven't been having any traction issues. Should I go lower to protect my tires from sharp rocks, or risk popping my beads in the middle of nowhere? I ask this because of my greater concern for the decrease in clearance I would have at a lower psi.

[Woods]

Fish - quick question, do you leave the deflators on while on the trail or take them off after they are done? I've read you can leave them on, but they see to stick out a lot and I'm afraid they'll get damaged or ripped off by rocks.

The general idea of leaving them on, is that you can put them on the valves then drive while they are deflating. I'd not leave them on for a long period of time. They are a fairly precision valve assembly so, I'd think that keeping dirt and moisture out of the internals would be a good idea. There's usually plenty of time to air down without having to drive, so I try not to drive with mine installed.

I run 14 PSI on my 33's. Generally the larger the tire the lower pressure you are able to run.

[seer1]

Just to stir the pot, I really like running at about 21-22 on my KMT2 285's. I had some issues with my Trailheads in that temperature effected them way too much. I ended up with the ARB deflator and really like it.

[Mutts08JK]

My Stock Sahara did ok when I was at Uwharrie in the mud without airing down in a few areas I had no traction at all but after airing down to about 15psi it was suprisingly better and for airing up it only took me oh about 2-3 seconds. Yes I said seconds. Being an avid paintballer I had a 4000 psi Nitrogen tank that was full and had gotten an Idea from a tool that Lowes sells. Well mine isn't regulated like the tool but works just as good with careful judgement and reasoning. IF YOU DON'T KNOW HOW TO DO IT DON'T BE STUPID AND TRY IT..... I had a coupler that fit the remote on a tank and connected it to an air chuck. Hmmmm opened the valve slowly and counted to 3 and had to let about 10 psi out of the tire. If you want to try this I reccomend using a nonlocking one to avoid over inflating the tire and I STRESS AGAIN, IF YOU DON'T KNOW HOW TO DO IT DON'T BE STUPID AND TRY IT..... Be Careful... They make regulated ones in several mags for around a few hundred bucks. or the one in lowes for about 80 something here are some links to them...

]http://www.lowes.com/lowes/lkn?action=productDetail&productId=166441-61735-J-6901-100&lpage=none

http://www.tellico4x4.com/product_info.php/products_id/28385

http://www.4wd.com/productdetails.aspx?partID=14192

Hope this helps out some

[midnight rider]

My Stock Sahara did ok when I was at Uwharrie in the mud without airing down in a few areas I had no traction at all but after airing down to about 15psi it was suprisingly better and for airing up it only took me oh about 2-3 seconds. Yes I said seconds. Being an avid paintballer I had a 4000 psi Nitrogen tank that was full and had gotten an Idea from a tool that Lowes sells. Well mine isn't regulated like the tool but works just as good with careful judgement and reasoning. IF YOU DON'T KNOW HOW TO DO IT DON'T BE STUPID AND TRY IT..... I had a coupler that fit the remote on a tank and connected it to an air chuck. Hmmmm opened the valve slowly and counted to 3 and had to let about 10 psi out of the tire. If you want to try this I reccomend using a nonlocking one to avoid over inflating the tire and I STRESS AGAIN, IF YOU DON'T KNOW HOW TO DO IT DON'T BE STUPID AND TRY IT..... Be Careful... They make regulated ones in several mags for around a few hundred bucks. or the one in lowes for about 80 something here are some links to them...

]http://www.lowes.com/lowes/lkn?action=productDetail&productId=166441-61735-J-6901-100&lpage=none

http://www.tellico4x4.com/product_info.php/products_id/28385

http://www.4wd.com/productdetails.aspx?partID=14192

Hope this helps out some

i had an idea for that same thing isn't it co2 it would be like haveing a mini power tamk.:yup:

[sintaur]

Don't think anyone mentioned this yet -- if you're aired down, keep your speed below about 20 MPH. If you turn the wheel while going too fast, you can pop the tire off the rim and instantly lose all the air in the tire. Think "aired down = 4WD Low."

]http://www.4x4now.com/sfjun96.htm

[pearl-drum-man]

Cheapo compressor from Costco works just great. Stock Rubicon tires air from 15 to 37 in 3 minutes each. Really a great little pump for 40 something dollars. :thumbsup:


X2, I have one and it did well, just gets really hot.

[jkkat]

X2, I have one and it did well, just gets really hot.

X3 I have one powering my on board air.

By the way the tank does help on the first one after that the air compressor takes over.

http://i243.photobucket.com/albums/ff229/JKkat/100_2303.jpg
http://i243.photobucket.com/albums/ff229/JKkat/100_2305.jpg

[pearl-drum-man]

X3 I have one powering my on board air.

By the way the tank does help on the first one after that the air compressor takes over.

http://i243.photobucket.com/albums/ff229/JKkat/100_2303.jpg
http://i243.photobucket.com/albums/ff229/JKkat/100_2305.jpg

That's a cool idea, maybe something to consider for those that air up a lot.

[whpony96]

Stauns are ok but if your looking for an easier way with a more adjustability get this.

http://www.northridge4x4.com/proddetail.php?prod=ARB-DEFLATOR

http://i243.photobucket.com/albums/ff229/JKkat/ARB-DEFLATOR-s.jpg

No! My buddy has this and he is always the last person to be aired down sine he can only do one tire at a time and I can do 4 at a time. Not to mention he HAD to read the directions to figure out how to use it!

So I wouldn't recommend this for those 2 reasons.

[whpony96]

I regularly air mine down to 15 psi and haven't broken any beads yet with the stock Rubi tires\rims. I know alot of other guys that run down to 8 psi, but 15 seems to have treated me pretty well.

I broke a bead on my stock rubi wheels at 15psi when I need to turn a slow sharp left. I rolled forward to get out of the sand and then cut the sidewall wide open! Ruined tire in less than one foot of travel. I would recommend 20psi.

[JKFirefighter]

I just picked up a power tank. Can't wait to give it a try, but now I've got to start buying more accessories. I got a 15lb'er ( it was a good deal at a local tire shop, they had ordered for someone else, who didn't come back); I would recommend a smaller tank as this is kinda huge. I can air up something like 45 35" tires, maybe I'll make some friends on the trail. I can also run an impact wrench or a framing nailer, I want to get a nailer now. Any ideas on mounting? I really wish Shrock would get making me a rear bumper that this would fit on, along with my spare and a jerry can and a cooler.:yup: Well, in the mean time where should I put this?

[IMFletch]

So on a stock Rubicon what PSI should I air down to for rock climbing?

- For light to moderate trail use I run the stock Rubi BFGs at 18 psi.
- For rock crawling somewhere in the 12-15 psi range works fine for me. Others say you can go lower for crawling but I have not found any need to go any lower.
- For sand or snow or soft snow 12 psi.

Experiment with different pressures. Try running a moderate line at street pressure, then air down to 18 and try it again. Run it again 13 and see what its like. You will be amazed at the increase in off road traction and ride comfort you get with aired down tires. It can be a hassle to air down and up but its worth the time.

Good luck.

[rballman]

I plan on doing light to moderate trails (maybe) ...do I really need to air down? I run the stock rubi wheels/tires on my X.

My only reasoning behind airing down would be to help not pop a tire on a rock or stick...so does airing down help this?

Thanks.

[Ryno]

I plan on doing light to moderate trails (maybe) ...do I really need to air down? I run the stock rubi wheels/tires on my X.

My only reasoning behind airing down would be to help not pop a tire on a rock or stick...so does airing down help this?

Thanks.

Airing down isn't necessary for light to moderate trails. I've done several trails in Moab and have never aired down. I've found that I have oodles of traction with the tires at street pressure.

I'm sure it would help make the ride less bouncy though. :bounce green:

[IMFletch]

I plan on doing light to moderate trails (maybe) ...do I really need to air down? I run the stock rubi wheels/tires on my X.

My only reasoning behind airing down would be to help not pop a tire on a rock or stick...so does airing down help this?

Thanks.

For light to moderate trails you do not have to air down.

[j33per]

I don't think these two things have been mentioned yet;

With beadlock wheels (as per picture) you can air down much lower than 15psi without worrying about the tires coming off the rim.

I bought the Staun deflators... but mine will only air down to 15psi. If anyone is interested in them, drop me a line. I will probably get the ARB one.

And finally; how does a tire that is aired down have greater resistance to being damaged by sharp rocks?

http://www.j33per.com/Rubicon%20Trail%202008/images/img_0355.jpg