jacksonpt

Airing down manually sucks. So I'm going to buy a set of automatic tire deflators. I've read a lot of good things about Staun Tyre Deflators. Anyone use them? Are they reliable? The kind of wheeling I do doesn't require them to be acurate to 1PSI, but I do need them to shut off. I've read about other (cheaper) deflators shut-off mechanism failing. I absolutely do not want that to happen.

ravencr

I'm wanting to get some automatic ones too, but I'm also really interested in the 4air thing that Roger Brown makes too. I think you can use them together too.

Chris

INsr5runner

last time I went wheelin, This guy in an Isuzu had them. He was telling me it was the best $$ he's ever spent on his rig.

Not to mention he stood there and watched as me and a friend aired my tires down manually. I thought they were pretty cool, but I don't mind airing down manually.

TDiddy

I've heard that they can be a pain to recalibrate. I bought a set of deflators for $15 when I ordered my recovery strap. They are manual, but then again I can always choose my new pressure.


QuickAir Tire Deflators

Robinhood150

I've got them and overall I'm happy with them. The only thing that I don't like about them is that if you want to air down to a pressure other than what you set them at, you can't use them. For instance, if they are set to 15psi and you want to go down to 12, then you still have to manually air down that remaining 3psi.

However, I recently had an epiphany and I figured out that I can set 2 of them for 15 and the other 2 for 12. Of course, that's twice as slow but you can still go and chat with the other people and make fun of them while they manually air down.

WATRD

I have had a couple of different brands and the Staun's are the ones I am sticking with The release valve so you don't have to have twice the pressure you are airing down to, to kick them off is a nice feature.

I sometimes put them on at the trailhead, then start driving and just take them off at the next stop, so they save even more time. In my opinion, they are worth the cash.

Mojo_Risin

Ditto here. I've had them for the last several months and they are great! "Set it and forget it" - It soo nice to just put them on not think twice about airing down with a little tire guage! Never had a problem with them not stopping. I usually take off my swaybar discos while the tires are airng down. - Thus saving time aswell.

As far as calibrating them - it's easy to do.

Also, another thing you could consider if the price is a bit steep for you, go in with a buddy and split the 4 deflators between the two of you - you get 2 he gets 2. As Robinhood stated - you can only do 2 at a time - but it's still faster that manually airing down and at half the price.

John

ravencr

If I wanted to hook one of these Staun deflators up to the 4air kit from Roger Brown, what pressure would I have to set it to to air down all 4 tires to 15 psi? Would it be 60 psi?

Chris

midiwall

I use the Staun's as well. I love 'em. Recalibrating them isn't that bad, it's a lot easier than other autos that use a hex wrench to set them.

The best thing about them is that they're repeatable. Many of the cheaper ones will get you at +/- 2 psi. From my playing with the Staun's they're dead-on everytime.

They also don't false-trigger. That $65 price for them buys you a REAL nice valving mechanism that will assure you that when they stop, you're were you set them. Again, some of the cheaper ones will stop, and then if you remove them and put them back on, you'll find that they'll start again.

And, one more thing... The Staun's don't require you to air up way past their set point in order to trigger. This can be handy if you're playing with different air pressures differing by just a pound or two. Again, some cheaper ones require an offset of 10psi or more to start again.


When you buy yours, hit up ebay (or your local store) and spend another $10 on a decent digital tire gauge. It will come in REAL handy for setting each deflator to the same pressure. Plus, most digital gauges have a backlight (or are LED based) which makes airing up after a night ride a whole lot easier.

midiwall

A couple of points...

1. From the Staun website (found with Google) the highest you can set the Staun's is 30psi:
   http://www.staunproducts.com/tire-deflator-features.php
   
   
2. From Roger's website (found with Google) you would set the one deflator to your normal off-road pressure:
   http://4crawler.cruiserpages.com/4x4/ForSale/4air.shtml
   "By setting one of the Oasis deflators to your normal off-road tire pressure, you simply screw it onto the 4air system and it'll take all 4 tires down to that pressure, without the hassle of getting all 4 deflators set to the same exact pressure."

Personally, I wouldn't use Roger's system to deflate. Doing so would remove the ability to drive the rig whiel the tires are deflating. Plus, I'm not too sure that it wouldn't take longer for them to come down.

ravencr

Thanks Midiwall! It would take 4 times as long to air down using the 4air kit, but the 4 air is nice for airing up faster. As far as driving while air down, that probably is pretty handy so I don't know. I'll probably just get the staun's and forget about the 4air kit, and just air up each tire independently.

Chris

P.S. It cost me $2.00 to air up all four tires from 18 psi to 40 psi this weekend.

midiwall

Did you make up your mind about going with an on-board compressor or CO2?

If you go with a compressor, you probably will _not_ air up that much faster. Even the largest compressor that folks run (like the ExtremeAire or the Viair 550c) doesn't have a high enough CFM rating to push enough air through Roger's hose network to do four tires in the time it takes to do one.

Remember, you're now sharing the volume of air that's coming out of the compressor, and that volume is generally fixed. So, if a compressor can bring one tire from 15-32psi in 3 minutes, and given that there's nothing else restricting the airflow coming out of the compressor, then you're looking at 12 minutes for 4 tires.

If you don't do anything to change the volume of air that you're pushing (the CFM rating), then you're not going to get anything done faster. When used with a compressor, Roger's system allows you to stand around for 12 minutes in one shot versus 4 shots of 3 minutes.

Now, if you're going to run CO2 - with an adjustable regulator - then Roger's system can help the total air-up time. You can open the regulator on the tank, increase the air flow at a given pressure, and thus decrease the air-up time.


Mark

ravencr

So really, in all reality his system doesn't save any time at all, since you have to set his up and then air up, where as without it you just begin airing up switching to each tire one at a time, which probably equates to the same amount of time with about the same effort, right?

Chris

midiwall

I don't mean to knock his system, I think it's a good idea and I've been tempted to order it a couple of times.

But, that said, from a mechanical point of view, you're not saving anytime because you still have to setup 4 points of contact for the hose network. In fact, if you add in the time that you'll spend in uncoiling an recoiling the hose, I'd bet that you'll lose time.

Where you _will_ save time is if you're running an air system that can deliver the volume to fill four tires in the same time as just one. To figure this out, it's straight math.

Say you're running a compressor that's rated for 1.34 cubic feet of air/minute at 30psi. For reference, that's a Viair 450c which is what I run. At that airflow, it takes me about 3 minutes to go from 15-32psi. Total air-up time is about 16 minutes which includes the time to pull the valve caps, pop the hose on, check the pressure at 3 minutes, put the valve cap on and move to the next tire.

There is _NO WAY_ to improve that time without increasing the air flow (the CFM rating) at the same pressure. The compressor is maxed out as it's pushing against the tire.

Now, if I added in Roger's hose network, the compressor won't put out any more airflow, and in fact, the back pressure will tend to increase since you have four tires in the system now. Depending on the compressor, that may _decrease_ the airflow at a given PSI, and thus _increase_ the overall time. The same airflow coming from the compressor will now be feeding 4 tires in a "equally cooperative" system. i.e., there are no favorites, all tires will get the same amount of air. Math shows us that if we started with 1.34CFM at 30psi, then we're now looking at 0.335CFM at 30psi/tire.

But... If we could quadruple the airflow and maintain pressure (i.e., head or 5.36CFM at 30psi), then we can reduce the time it takes to inflate the four tires to just 3 minutes - total.

In practical terms, this will only be accomplished on our rigs by running a CO2 based system. Given that CO2 is at such a high pressure (1500psi) and that you should be running an adjustable regulator, then you can open the regulator to allow more air (well, CO2) to run into the hose network. This is cranking up your CFM rating and it _will_ decrease your total air-up time.


So, Roger's hose network _is_ a good thing. It's a cool idea, but you have to be running the pressure on the backside to be able to support it.


Oh, one other cool thing about it... Because of the nature of the design (what I called an "equally cooperative system" above), you are assured that each tire will have exactly the same pressure in it. So, you can take your pressure reading from one spot (either during inflation or deflation) and you know that each tire is the same as what you're reading from the single point.

Mark

ravencr

Awesome Mark! I'm going to get the Staun deflators, and will probably air up using gas stations for now, and then down the road, I'll probably just use the ARB compressor, so I can air up (slooowwwly), but not have to spend a lot of money on the Powertank Co2 system. In my opinion, it's not a "need", just an amenity to make things easier. So, I'm going to have to live with airing up a lot slower, but I like and can afford the Stauns now.

Thanks for all the help,

Chris

midiwall

'k... Be careful driving with deflated tires on hard roads (i.e., that trip from the trail to the gas station). You can pop a bead (where the inner edge of the tire pops out of it's hold on the rim).

That's not a good thing - you can ruin your rims if you don't catch it _immediately_.

Gadget

I have a set of them. They work great and are so much better then manually airing down. They are kind of a pain to setup but that is well worth it when it comes time to air down.

I am going to get a second set and set them up for a lower pressure so I can have two preset pressures as needed.

Let me tell you this, when our group pulls onto the trail to air down I always get comments about how much everyone else would really like a set.

Gadget

www.GadgetOnline.com

ravencr

Gadget, I've been airing down to 18-20 psi, and I was wonderig what some other people air down too on the trail? I've heard as low as 10 psi, but I'm scared to damage the aluminum rims.

Chris

jacksonpt

I think it depends on tire size.

For me, wtih my 32/11.5-15s on 7" wide rims, 20psi is about perfect. I still get a nice big footprint, and my tires still form well over/around rocks, but I don't have to worry (much) about losing a bead or damaging the rim.

midiwall

15 is common amongst the group I run with. The lower you go, the more chance there is of popping a bead.

10 is pretty low if you're not exclusively in the sand, unless you have bead lockers.