Overfilled Tires + Summer (+ tire deflators)

[Markos]

All:

I was wondering if anyone has run into issues in the summer from their tires heating up in the summer, causing the pressure to increase.

I bring this up because I've been searching around for alternative adjustable tire deflators (other than Staun and Oasis). Anyway, I stumbled upon these. I figured you could set them to a low pressure before you go offroading, them keep them at a high pressure when you are doing the daily driver thing. Otherwise, set the lock on them to prevent any venting. They require a hole drilled in the wheel, normally used in circle-track racing. They could serve a dual purpose at the same cost as Stauns ($62.99).

http://www.pegasusautoracing.com/productselection.asp?Product=3336
Instead of guessing how much your tire pressure will increase as the tire temperature increases, these relief valves let you set the tires to the desired pressure and automatically vent excess pressure as you race. Their reliability has been well proven by thousands of circle track racers from Winston Cup on down. Features lightweight aluminum construction (only 9 grams), built-in 100 mesh filter and an enclosed poppet for protection from dirt. They can also be locked shut. To install, just drill and tap a 1/8 NPT hole in the rim by the valve stem. If your rims are too thin to tap steel wheels, for example), just drill a 3/4 inch hole and use the (included) Teflon™ sealing jam nuts on the inside of the rim. Adjustment range is from 5 to 40 psi.

http://www.pegasusautoracing.com/Images/L/3336.JPG

[Fire Ball]

Tire pressure usually drops about 1 psi per month at least due to leaks. Also the pressure changes about 1 psi for every 10 degrees temp change.

[lancetkenyon]

From 5 PSI to 6 PSI isn't necessarily a bad thing.

[Fire Ball]

With my POS tire gage I'm lucky if my tires are within 5 psi of each other :D

[FrenchChili]

From what I understand, Rick Beer said to keep your pressure at their psi for max load rating; prevents sidewalls from heating up. I thought lowering air would help on highway, guess I was wrong and actually accidentally tested it on the trailer. Tires were supposed to be at 35psi, had them at 30psi cold, drove to Tucson towing the Jeep, arriving there they were at 35psi, and burning to the touch, bad bad bad.

[TRLR8TDTJ]

From what I understand, Rick Beer said to keep your pressure at their psi for max load rating; prevents sidewalls from heating up. I thought lowering air would help on highway, guess I was wrong and actually accidentally tested it on the trailer. Tires were supposed to be at 35psi, had them at 30psi cold, drove to Tucson towing the Jeep, arriving there they were at 35psi, and burning to the touch, bad bad bad.

Trailer tires should have more than 35psi in them. Mine are at 50psi. It could be the tires are not rated for the weight.

Kyle

[GRUNT]

I am by no means an expert on anything but wouldn't venting the air leave you at a loss when the tire cools down and the PSI drops because it cooled and you vented some pressure...?

I think I misunderstood the gist of the thread, sorry....

[RokNRich]

From what I understand, Rick Beer said to keep your pressure at their psi for max load rating; prevents sidewalls from heating up. I thought lowering air would help on highway, guess I was wrong and actually accidentally tested it on the trailer. Tires were supposed to be at 35psi, had them at 30psi cold, drove to Tucson towing the Jeep, arriving there they were at 35psi, and burning to the touch, bad bad bad.


Gee, ya think ? Lucky you didn't have a blowout :rolleyes:

As far as the deflators, usually I will air down as soon as pulling into the airdown, try to get them down before they cool. If it's cool in the AM when we start, I will often check the pressure after it warms up a bit and the first few obstacle are behind us, it only takes a 15-20 seconds to drop the air down a few psi at that point.

[Markos]

I am by no means an expert on anything but wouldn't venting the air leave you at a loss when the tire cools down and the PSI drops because it cooled and you vented some pressure...?

I think I misunderstood the gist of the thread, sorry....

Yeah I was thinking the same thing on my commute home this evening. Basically, if you left the relief valve open all the time, you'd constantly be filling your tires. I'm also wondering if you have to tighten them all the way down in order to 'lock' them. Otherwise, think of them as permanent mounted tire deflators, similar to the Powertank or Klune valves, but adjustable. Without any added advantages, I don't think it's worth drilling a hole in my wheels...

[Turtle]

On the subject of tire deflators... I would like to purchase a set... However the ones I want are specific... I know a few of you out there have them... So tell me what they are and where to get them!

I am looking for the ones that you set for a certain PSI. Then you screw them onto your valve stems and they release the air... They drop down to the preset PSI (that I assume you set) then they stop. Screw them on at the air down spot, forget about them and pull them off when you get to the trails...

WHAT ARE THESE???

TURTLE!

[Markos]

Turtle:

There are three types of adjustable deflators.

1. Staun (this is probably what you are thinking of)
2. Oasis/Trailhead
3. Tire Buddy.
4. If you feel like drilling holes in your rims, you can use the ones listed above also.

Check out this comparison link: http://www.parksoffroad.com/prodreview/deflatortest/deflatormain.htm


You can probably get some from 4 wheelers supply in town, so check there first. Otherwise, take a look at Jeepinoutfitters.com for Stauns or Oasis. The tire buddy models must be bought from the tackle store that makes them:

http://shop.oysterbaytackle.com/index.php/cPath/35

[FrenchChili]

Gee, ya think ? Lucky you didn't have a blowout :rolleyes:

As far as the deflators, usually I will air down as soon as pulling into the airdown, try to get them down before they cool. If it's cool in the AM when we start, I will often check the pressure after it warms up a bit and the first few obstacle are behind us, it only takes a 15-20 seconds to drop the air down a few psi at that point.

We all learn something new now and then. How did you learn about this? Were you the little nerdy kid in physics class? Sorry I'm not to your level, but I'm 21, limited in experience and haven't yet got my Masters at Goodrich School; at least I ASKED Rick about it and now I know:):p


Lowering at trail pressure: I heard some people use a valve core remover, with good timing it must take nearly no time! At work(bikes) we do it sometimes on fully pressured tires, I can imagine it would be fairly simple to airdown that way, it's easy to insert the core even when air is gushing out.

[RokNRich]

We all learn something new now and then. How did you learn about this? Were you the little nerdy kid in physics class? Sorry I'm not to your level, but I'm 21, limited in experience and haven't yet got my Masters at Goodrich School; at least I ASKED Rick about it and now I know:):p
.

Maybe you should have asked before you put the trailer on the freeway. :rolleyes:

Neil, I do stupid crap all the time, no big deal, no reason to get your lingerie in a bunch ;):)

[ademster]

Neal... now that you know about the trailers tire pressures..... also another thing you should check is the Lug Nuts... make sure they are torqued to specs... and you must check them every 500 miles.

Dont let him get to you... he just like to make him self feel better.

[Fire Ball]

The tire on the trailer is meant to carry a load and not much else. It can be run higher pressure since traction is not an issue.

The tires on your vehicle are a different matter. The tire contact patch is very important since traction depends on it.

Too little pressure and they flex too much, friction causes heat and the tire can fail. Too much pressure, the contact patch is too small and can cause loss of traction. Plus an over inflated tire, when heated could be high enough pressure to cause a failure. Radials and bias ply tires also need different levels of air. Don't mix them on your vehicle.

[GRUNT]

...Radials and bias ply tires also need different levels of air. Don't mix them on your vehicle.

I wouldn't have thought of that, good point! I never mix types, brands on my rigs so I never gave that thought but I know alot of the thrifty wheelers around here do what they got to do to stay on the dirt... :D

[lancetkenyon]

Neal... now that you know about the trailers tire pressures..... also another thing you should check is the Lug Nuts... make sure they are torqued to specs... and you must check them every 500 miles.

Dont let him get to you... he just like to make him self feel better.

He makes me feel better about myself everytime I wheel with him!;)

[drroadie]

I use rubber tire valves on my junk due to haveing broken off a steel valve on a rock many years ago. I would fear the same thing happening to a steel deflater mounted permanatly on my wheels. For my money it's worth screwing them on the valves each time, and removeing them again. Just my
.02.

[Billy 4 hp]

All:

I was wondering if anyone has run into issues in the summer from their tires heating up in the summer, causing the pressure to increase.

I bring this up because I've been searching around for alternative adjustable tire deflators (other than Staun and Oasis). Anyway, I stumbled upon these. I figured you could set them to a low pressure before you go offroading, them keep them at a high pressure when you are doing the daily driver thing. Otherwise, set the lock on them to prevent any venting. They require a hole drilled in the wheel, normally used in circle-track racing. They could serve a dual purpose at the same cost as Stauns ($62.99).

http://www.pegasusautoracing.com/productselection.asp?Product=3336

http://www.pegasusautoracing.com/Images/L/3336.JPG

Well, we use those on winged sprint cars and they are touchy at best, very susceptable to dirt / debris getting into them and causing a total loss of air pressure as it is a moving mechanical valve... The do work well in their intended application, but that application is very limited and has inherent risks...

A basic dirt race car example is we start at 8 psi, due to the load from the wings and speeds involved we maintain 7 - 8 psi with the bleeder, (without it tire pressures would increase to almost 20 psi). If there is a red flag (all cars have to stop on the track for 3 to 10 minutes) and the tire cools down we restart on basically a flat tire (1 - 2 psi) since the bleeder has had to work so hard to maintain the 7 - 8 psi that it has let all the air out of the tire as it heated up than once it cools there is very little air left in the tire to even keep the sidewalls up. This scenario is very similar to what a large diamter offroad tire would do with a bleeder (start out a 18 psi and then drive down the freeway for 10 miles than check your tire pressure, depending on a few factors it pretty easy to gain 10 to 15 psi in that short distance at freeway speeds).

We won't even use them on a pavement sprint car due to the inevitable disaster that they cause if the "bleeder" fails...

Basically if it's a on the road vehicle or DD I would steer clear... Just another "part" to fail and put you on the side of the road or worse on your lid....

If your that concerned about air pressure increases or decreases due to ambient temps, switch to an inert gas... Ala nascar, irl, road racing, etc... A IRL car with 4800 lbs of down force traveling 200 mph average laps barely gains 2 psi with inert gas in the tires over a 30 plus lap run on a 1.5 mile racetrack...

JMHO

[Markos]

Thanks Billy! As long as you keep that engine pic in your sig, I will have great respect for your suggestions. :)

[Billy 4 hp]

Thanks Billy! As long as you keep that engine pic in your sig, I will have great respect for your suggestions. :)

Ya mean my whole internet credibility is from one lousy pic??? :D

I thought it was from years of dedication to the custodial (mechanical) arts..... :eek:

No offense implied to any custodians who might read this....

[Markos]

Ya mean my whole internet credibility is from one lousy pic??? :D

I thought it was from years of dedication to the custodial (mechanical) arts..... :eek:

No offense implied to any custodians who might read this....

This is the internet. Never underestimate the power of a well placed image. :D

[lancetkenyon]

Yeah, look at my avatar. Get lots of respect with it.