Max Min tire pressure settings in TPMS App

[AV8R]

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


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

I apologize... I thought you were kidding. But you really did this. And you even have the FOBO t-valve stems. Didn’t the sensors fit and clear the brake calipers off these t-valves, or what drove you to put them inside?

 

[Lowndes]

I apologize... I thought you were kidding. But you really did this. And you even have the FOBO t-valve stems. Didn’t the sensors fit and clear the brake calipers off these t-valves, or what drove you to put them inside?

AV8R,
I had thought it was important to know the tire temp but after considering everything realized that it's only the pressure I am interested in anyway and pressure is a direct function of the temp, unless there's a leak. Only track slicks need temps, not DOT tires.

The sensors clear the calipers, no prob. The sensors aren't nearly as wide as the mag spokes.

 

[ST Gui]

I had thought it was important to know the tire temp

I've never considered the temperature but that's just because I don't care not because it may or may not be important. Curious though if you had occasion to notice much difference in temps between having the sensor outside and inside the tire. Much has been made about that differnce without actually specifiying the delta. Just curious as I only pay attention to the pressure.

 

[Lowndes]

I've never considered the temperature but that's just because I don't care not because it may or may not be important. Curious though if you had occasion to notice much difference in temps between having the sensor outside and inside the tire. Much has been made about that differnce without actually specifiying the delta. Just curious as I only pay attention to the pressure.

ST Gui,

No empirical data but to my surprise, the front and rear were always very close in temp. This was on the K with the front sensor inside and the rear outside, 38 psi front, 42 psi rear, +/-.

What most surprised me was how much the pressures fluctuated during the day, as much as 7 psi normally but with a cold morning start, even more. Ambient air, speed, road surface, even sunlight on the tire would bump it 2 psi by itself.

I immediately gave up being so anal about the psi. What's the use, it never stays the same very long. "Always measure the PSI cold". Well, just HOW "cold"?? I see it's 39 psi, must be about 40 deg F this morning.

 

[ST-Traveler]

You probably could just leave the temps set at the factory settings and be fine.
Then adjust your PSI limits to what you need. Low @35PSI and High at 52 PSI

 

[Lowndes]

I set my Lo temp alarm way low at 25F and the Hi-temp at 55F, but your numbers would be just fine in most "warm" locations. This prevents unnecessary alarms and flashing lights and possibly running the battery in the display down at night or a cold AM ride. The PSI is the MAIN THANG. You might get a slow leak on a hot fast day that would heat up the tire before the PSI alarm sounded or you noticed the handling.