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Since we're having some cold weather here(cold for Florida, anyway), I occasionally get the tire pressure warning on startup. Since I have 35-36 psi in them, I don't worry much about it. However, I've noticed that as the tires warm up past what should be the safe pressure level, the light stays on until I shut the bike off and restart.
At what pressure does it come on, and have others noticed that it won't go off?
 

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I had the same issues on our Roadmaster. The cure is actually pretty simple, I let the air out and filled the tires with nitrogen, have not had an issue since then. Before the tires would generally have a 10psi swing, now they might move only 1 to 2 psi. I run nitrogen in all my vehicles so I thought I would try it on the bike, worked very good!!
 

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I had the same issues on our Roadmaster. The cure is actually pretty simple, I let the air out and filled the tires with nitrogen, have not had an issue since then. Before the tires would generally have a 10psi swing, now they might move only 1 to 2 psi. I run nitrogen in all my vehicles so I thought I would try it on the bike, worked very good!!
Howdy Folks,
The nitrogen is probably the best solution. If I adjust the pressure in my Chieftain's tires to factory spec at an ambient temp of 70 F, with compressed air, the extreme swings in temperatures we get in the Chihuahuan Desert result in the warning light either coming on because its cold and the pressures are low, or because its hot and the pressures are high. Then, sometimes, it just loses signal from the sending units in the wheels for a few minutes and THAT will light up the warning icon. I keep an eye on the pressure as displayed on my dash but don't pay much attention to the warning light.
--- Randall
 

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Howdy Folks,
The nitrogen is probably the best solution. If I adjust the pressure in my Chieftain's tires to factory spec at an ambient temp of 70 F, with compressed air, the extreme swings in temperatures we get in the Chihuahuan Desert result in the warning light either coming on because its cold and the pressures are low, or because its hot and the pressures are high. Then, sometimes, it just loses signal from the sending units in the wheels for a few minutes and THAT will light up the warning icon. I keep an eye on the pressure as displayed on my dash but don't pay much attention to the warning light.
--- Randall
I agree. Mine usually comes on when cold and then goes off when the tires warm up.
 

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I had the same problem in Sturgus this summer. The tech told me to go on the hiway for about 10 miles, did and light still on. The service manage told the tech to hookup the computer and reprogram the setting in the bike, he did and no problems since then. Hope this helps.
 

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Yes i agree as my Chieftains tires do exactly that. Never heard about the nitrogen before! Going to give it a go!
Have nitrogen in my car. The molecules are supposed to be larger and not as susceptible to leakage and also tire pressure variation. Have had no issues with the car tires or my new truck before that.
 

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Hate to be the wet blanket here, fellas, but nitrogen's got nothing to do with it. It obeys the same long-established gas laws as every other gas in the universe. It expands in the heat and contracts in the cold or conversely, if confined, the pressure goes up/down. The difference in nitrogen and air (mostly nitrogen itself) in that regard is so miniscule you wouldn't be even remotely able to detect it with a tire pressure gauge. Further, the difference in the diffusion rate through rubber tires is on the order of 1-2% and something you would be very hard pressed to notice amidst all the heating and cooling cycles and leakage from other sources. Measured 0.02 psi lately? Google Boyle's Law, Charles' Law and the Ideal Gas Law. There is tons of hype available re N2 in tires available on the internet. I haven't seen a claim to cure cancer yet but some come close. Don't believe it and don't believe me, either. Check it yourself. The IGL computations are pretty straightforward, just get a periodic table and do the math yourself. I can save you some pencil lead and a couple Motrin, though. It won't add up.

For those of you sweating the pressure, don't. If you fill even close to the recommended psi, you'll be fine. The mfrs know about these gas laws and if you pick up ten or twelve psi when the tire heats up, you're still fine. It will maintain the proper profile, contact etc. They're designed to a range, not a point, between under and overinflation. The max inflation psi is just that. Exceed that and you change those profiles, contacts etc as the tire heats up and moves into the overinflated category. It won't explode. The thing likely won't physically fail until you get well above 100 psi, so don't sweat that. Hell, the rim may come flying apart before the tire does. Many a trucker's been killed learning that.

For those of you with TPS problems that were "cured" when you emptied the air and refilled with N2, I submit that it was the act of emptying and refilling that did it and not what you may have refilled the tire with. Sort of like maybe zeroing the transmitter and resetting it perhaps. Maybe blew out an interfering dust mote. Could be the electronics acting up. Can't say. I can say it's not the nitrogen.

Lastly, some claim it keeps the tires from going bad early by omitting oxygen within the carcass. Ever seen a tire go bad from the inside? I haven't. All those little cracks that show up late in tire life between the tread and whatnot are from UV and ozone which are not found inside the tire. Take that cracked tire off and look inside and it will likely look pretty much like the day it was mounted.

Having said all that, there is no harm in using it, of course, but at this level for what we do and how we use it, it is a huge PITA to go on a pure nitrogen economy for your tires and in the end, it is pure placebo. My take? Waaay not worth the bother.

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I agree that the difference in nitrogen and compressed air has little to do with nitrogen. What does affect the expansion of a gas is moisture.
Ambient, humid air compressed and used to fill a tire will have more pressure fluctuations with temperature than dry nitrogen.


However, none of that info fixes the fact that the TPMS warning will not go off even after the air warms up and expands in my tires...
 

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I agree that the difference in nitrogen and compressed air has little to do with nitrogen. What does affect the expansion of a gas is moisture.
Ambient, humid air compressed and used to fill a tire will have more pressure fluctuations with temperature than dry nitrogen.


However, none of that info fixes the fact that the TPMS warning will not go off even after the air warms up and expands in my tires...
Mine does the same thing; The light won't clear until I shut it down and restart. I agree with Forty-one that the tires will function just fine with the range of pressure variation compressed air expansion yields.

I became curious a few years ago about why the tire pressure warning was coming on all the time in the Suburbans our school uses. I researched it on the internet and discovered that the dealerships and high-end tire stores were using nitrogen. The general opinion on the postings I saw were that the nitrogen gives less pressure variation, but none of it went into whether that was due to the characteristics of the gas or was due to less moisture. Inquiring minds want to know...
--- Randall
 

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I agree 100% Forty-one. I keep my tires at 36-39 front and 40/41 rear, with 78%nitrogen/21%oxygen, or air, :), and I've not had a TPMS problem in over 14,000 miles. I've gone from sea level to 10,000'ish, and temps from 30-100 degrees f, and no problems. I pay attention to upcoming temp changes and make sure I have the appropriate tire pressures but I haven't had to add air many times at all.
 

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Dan,

Don't want to come across as combative, but I will have to respectfully disagree. Water vapor is a trace constituent in air and would have no measurable effect at our level of usage. I submit that dry nitrogen or compressed air, which is pretty dry as we normally use it, could not be differentiated by Joe Motowrench in every day use which tells me there is no real point in going to the trouble of seeking out N2 when you need to adjust your tire pressure. All evidence to the contrary that I have seen regarding N2 in general has be poorly measured, uncontrolled, anecdotal wishful thinking. Not the least of which comes from those who charge you for the pleasure and have a vested interest in keeping the terms" nitrogen" and "snake oil" generously separated.

It is true that water expands something like 1800x when turning to vapor, but we are past that, it's already a gas and responds collectively with the other molecules in the gas mix to temp and press fluctuations. I'll stipulate that water vapor conducts heat better (I don't know the thermal conductivity of water vapor vs pure, dry nitrogen - it may even be a better insulator, dunno) but at a molecule or two per hundred, you'd be hard pressed to measure the diff, either direction, even with very sensitive instruments. Again, Joe Motowrench filling his tires before a Saturday ride isn't going to possibly notice any of these effects.

I think we are splitting hairs here and going down dead ends with all the physics 101. It addresses one of the proposed "cures" but not your problem. Your problem, if it is one and I don't think it is, sounds electronic, not what's in the tires. If I understand your original post correctly, it sounds like you may be a trifle low on start up and the low press light won't go off when the tires have warmed a bit? I think that's just the computer program and that it keeps telling you, like some of those other fleeting trouble codes, that something is going on and it's going to keep telling you until the ign is shut off, because it is a smart computer and you are a stupid human, and if you don't rectify it, it'll start nagging you all over again next cold start up. After you've warmed the tires up and gained a few psi, the computer is happy again on a warm start up because it doesn't know they're warm, it just knows the pressure's ok, (yeah, computer, who's the dummy now?) but you'll have to rinse and repeat when they cool down again. Mine are pretty good in that they warn when it gets down a pound, maybe two which I like to know. It doesn't go off until they warm up past 36 psi and I shut down or I add air when cold. Bottom line is that I don't think anything is wrong. Give it a short squirt from your compressor and be on your way. Shut that pesky computer up for good.

The nagging light doesn't bother me near as much as the delay in displaying the pressure until you're moving. I can kill the ign at a stop light and reset the warning but I'd rather push a button and see the psi before I go rather than rolling the tires around in those generously valanced fenders to access the valves. Suffer with the idiot light or turn around and fill if you're low. Yeef. I am a couple miles from a gas station so I lose the cold fill benchmark as they warm so I turn around and hit the compressor at the house real quick and then re-shove off a couple minutes later.

On a different note, back in town for a while? Staying long?

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Yowzah, not one slimy little molecule seeping through the lifter block gaskets. It's been so good I've even stopped giving it the evil eye so much. Wish we had your wx. Only a hundred or so miles of N lat on you but we never got out of the forties. No huge deal but I find the Michelin Man preps getting more tedious as the winter wears on and the riding more onerous than enjoyable. Still headed your way prob Mar-Apr or maybe May if I can't get unstuck from the swamp here. I'll PM you as a date firms up and draws nigh. Hope you won't be stuck in some third-world armpit working to keep our tanks full. My apologies to the lurkers and posters for the personal digression.

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Right down the road from my Mission City Indian Dealer in Boerne Texas is Lester's Tire Center, after picking up my new Chieftain, I stopped by and they exchanged the air in my bike's tires for a Nitrogen Tire Fill.

Nitrogen has larger molecules and thus does not leak like air does, it runs cooler on hot days and better tire wear and handling. The tire pressure does hardly move between cold and hot days, they stay busy with a lot of bikers from the Indian Dealership to the nearby Harley Dealership per the shop manager.

Total cost was $10 and I probably can go a year or more without getting a low tire, just like I did no my old bike.
 

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Okay, Roadie, I'll bite. No air? For a year? I'm calling bogus. All tires leak, even a little (and even with N2!) and seasonal temp variations alone will drive you to a compressor. Apparently nothing previously posted registered so perhaps the fact that for all the difference you can discern between air and nitrogen, you may have just paid a guy ten bucks to air up your tires. Seems a little stiff to me but it's your dime. Not saying he did, but you won't be able to tell the difference in common usage. Easy to check btw, just bleed some and see if it will support combustion. N2 won't. The eager, yet likely ignorant, service manager probably doesn't even know, but he does know people come in waving a sawbuck around at him to dump less than a penny's worth of N2 in their tires. If he does, shame on him. Either way the businessman in him is not going to hang that up all of sudden. That's nearly pure overhead neutralizer. Man, this is a fad that I thought was put to bed a couple years ago.

Again, to keep with the theme - if you can't possibly tell the difference in common usage, what's the point? Urban myth, superstition, a placebo. That's all it is. I defy you to prove otherwise with some cold, hard facts not outlandish anecdotes. Sheesh, y'all just air up and ride fercryinoutloud.

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I have run nitrogen in all my motorcycle tires and since the molecules are a lot larger than air, it takes up to a year to you need to add more. Nitrogen is hardly effected by heat or cold, so your tire pressure hardly changes. Run it in all my vehicles and have for years.

Some of my buddies HDs came new from the dealer with Nitrogen already in the tires and with green valve caps meaning Nitrogen install.

It just works.
 
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