Max Min tire pressure settings in TPMS App

[paulcb]

My TPMS is probably the last farkle I'd give up. That being said, while I occasionally look a the temps out of curiosity, I think they are pretty useless and don't care about them. The temp you see is not even the temp of the tire itself, just the air inside. The temp on the outside surface of the tire is much much hotter, especially the rear. The tires are designed for such use, thus the temps are of no worry to me, as long as my pressures are OK when I start out for the day and don't go low during the ride.

For the same reasons, I don't really care about the max pressure either, as long as the pressure was correct when cold. The only thing we control is the pressure when cold, everything else is an output of that.

 

[dwalby]

I would not worry too much about the sensor temp accuracy because the sensors are in the airstream, not inside the tire.

yes, that's true, and would explain a lot of the temp inaccuracy (in fact may suggest the temp readings are pretty much worthless). However, my reply you quoted was in response to the OP showing that the F/R temps were 9F apart after the bike had been sitting in the garage for a few days. And it was 10:23PM so no sunlight effect.

 

[AV8R]

The highways in my area are in sad shape and full of fodder. Plus, the tasks at hand often necessitate riding on the shoulder, gore and pie points of ramps, and other areas where fodder is pushed aside.

Ive already fixed a mate`s flat and have a valve stem slow leak myself. The BT tpms device sure makes it easier to keep track of the pressure, especially the hard to access rear tire.

One of the best $100 ive spent on this bike. Embrace the tech
8)

 

[ST-Traveler]

That being said, while I occasionally look a the temps out of curiosity, I think they are pretty useless and don't care about them.

Page 125 in the O/M states "under inflated tires can over heat and fail"

 

[ST Gui]

Page 125 in the O/M states "under inflated tires can over heat and fail"

So pay attention to the tire pressure and no worries about the temperature.

 

[ST-Traveler]

So pay attention to the tire pressure and no worries about the temperature.

If you pick up something and slowly loose pressure you will want to limp along to get to the next stop. Pay attention to the temperature. PG 153, "it may overheat and blow out."

 

[ST-Traveler]

In the picture it appears you are showing dry rot on the valve stem rubber seal?

 

[dwalby]

If you pick up something and slowly loose pressure you will want to limp along to get to the next stop. Pay attention to the temperature. PG 153, "it may overheat and blow out."

Having experienced a few flat tires, once they get low enough that overheating due to friction would even be a concern the bike feels so squirrely you usually pull over and stop anyway. That's been my TPMS for 40 years, "not squirrely -> keep riding, squirrely -> pull over and repair flat tire"

 

[T_C]

Page 125 in the O/M states "under inflated tires can over heat and fail"

So what is the temperature of overheating??

 

[AV8R]

In the picture it appears you are showing dry rot on the valve stem rubber seal?

Stem isnt yet one year old. It is likely being stretched by the metal stem and FOBO
Soon these will be replaced with an all metal (on outside Fobo product).

 

[Lowndes]

I found a way to mount the FOBO sensor INSIDE the tire and get accurate TIRE temps. Works very well, actually. Got pics of it, too. Then I realized that it really didn't matter. All we are really concerned about is the pressure anyway. And if the pressure goes up while riding, the only possible cause would be the temp. And the pressure is directly proportional to the temp.

 

[T_C]

I found a way to mount the FOBO sensor INSIDE the tire and get accurate TIRE temps.

Would be curious to see how you did? Keeping it accurate on pressure and temps.

 

[paulcb]

I found a way to mount the FOBO sensor INSIDE the tire and get accurate TIRE temps. Works very well, actually. Got pics of it, too. Then I realized that it really didn't matter. All we are really concerned about is the pressure anyway. And if the pressure goes up while riding, the only possible cause would be the temp. And the pressure is directly proportional to the temp.

You're only seeing the air temp inside the tire, not the actual tire temp, which varies from outside to inside as well as up and down the sidewall. I think the temps from any TPMS are pretty useless, especially since we have no control over them if the tire is properly inflated, unless we just ride and corner slow and easy!

 

[Larry Fine]

I found a way to mount the FOBO sensor INSIDE the tire and get accurate TIRE temps. Got pics of it, too.

Well???




j/k, but we really do wanna see them.

 

[Lowndes]

You're only seeing the air temp inside the tire, not the actual tire temp, which varies from outside to inside as well as up and down the sidewall. I think the temps from any TPMS are pretty useless, especially since we have no control over them if the tire is properly inflated, unless we just ride and corner slow and easy!

Paul, I see you've been streaming Dave Moss!!

Well???




j/k, but we really do wanna see them.

Or, as the BMW forums say, "Without pics, it didn't happen." !!

OK. OK. Had to go back an' dig 'em up from '17. Mounted one in the front tire as a proof of concept on my '00 BMW K1200RS (the famous "Flying Brick") in Nov, '17, and ran it until last week when I replaced the Metz M7's. WORKED WELL the entire time. The rear sensor was mounted exterior on the rubber valve stem, again, no problems. And I ran it hard all thru the mountains of TN, NC, GA, and Southern VA.

Used the FOBO T-valve and drilled a side-to-side hole just above where the sensor and locknut stop. This lets air in and out of the tire. The T-valve is threaded 23mm which is plenty to clear the rim, inside seal/washer/nut, hole, and sensor. See pics.

FOBO said it wouldn't work because "the signal wouldn't penetrate the tire." I had a hunch it would and was vindicated. Works fine. Didn't even notice a decrease in range. They were surprised and interested when I reported success.

FOBO did tell me the sensors they use are GE, Bluetooth, read with much closer tolerances on pressure and temp, plus a much shorter report period than OEM (inside the tire) type 433mHz automobile sensors.

FOBO engineering also said, which I found very interesting:

"For the GE sensor, it's using absolute pressure referenced to sea level pressure. This means it is altitude compensated, so if you live in high altitude, you just need to follow the Fobo reading. Hand gauge will be inaccurate at high altitude as it will read higher due to lower atmospheric pressure. This will result in lesser air and many users are not aware of. Hope this explains."

The only problems I foresaw would have been a flat tire while rolling (crushed sender), or a dead battery in the sender. Neither happened, thankfully.

Hope this helps the non-believers!!

Lowndes

Entire series here: https://photos.app.goo.gl/YLLqQM4rHcccfbbK2

 

[dwalby]

FOBO engineering also said, which I found very interesting:

"For the GE sensor, it's using absolute pressure referenced to sea level pressure. This means it is altitude compensated, so if you live in high altitude, you just need to follow the Fobo reading. Hand gauge will be inaccurate at high altitude as it will read higher due to lower atmospheric pressure. This will result in lesser air and many users are not aware of. Hope this explains."

I find this interesting as well, in a purely academic sense. When you ride at altitude the ambient air pressure drops, and since a tire pressure gauge reads differential pressure, it will read higher than at sea level, because the differential pressure IS higher. But let's say you live at altitude and filled the tire for the first time at altitude, don't you just set it to the same differential pressure as you would at sea level??? I've never seen anything in a tire spec that indicates you need to compensate for altitude when filling a tire with air, and raise the recommended psi accordingly, but maybe I've just never known before because I never lived at altitude. The practical difference is only a couple of psi, but easily measurable.

So this asks the question, if the tire is spec'd at 42psi cold, does that spec mean you fill it with air so that the absolute pressure inside the tire would have 42psi differential pressure at sea level, or with enough air to have 42psi differential pressure for the ambient air pressure? Or stated differently, is the way a tire responds to inflation based on an absolute pressure, or differential pressure? I'd suspect differential, but the FOBO engineers are suggesting absolute.

 

[T_C]

I did notice a pressure change when riding on the high plains. That was with my Orange unit. Haven't had the FOBO back out there to test yet, but it will be, on the wheels of the trailer.

 

[paulcb]

Paul, I see you've been streaming Dave Moss!!

Who’s Dave Moss?

 

[Lowndes]

Who’s Dave Moss?

Hey, Paul,

Dave Moss is a motorcycle suspension and tires guru. Was watching one of his vids this week about reading tires and he was measuring tire tread temps all around the tire, center and both sides down the sidewall and what the different temps and wear patterns tell you about the tire pressure and suspension.

He has a bunch of youtubes that get into suspension setup that are very easy to understand and simple to apply to any bike for improved handling, safety, and tire mileage. I never knew anything about suspension setup, just got on and rode it. Makes a huge difference when it's right, kinda like carburation.

Dave Moss on suspension setup ("setting sag")


Lowndes

 

[ST-Traveler]

I found a way to mount the FOBO sensor INSIDE the tire and get accurate TIRE temps.

FWIW
I mounted the Duran sensor inside the rim once and it came off. Rattled around in there until the next tire change. Needless to say the sensor was trash after that and had to buy a new one. After that I said to myself I would never put a senor like that inside the rim again. Just my .02