FOBO TPMS while riding

[mrazvi]

Hello, I recently installed a FOBO TPMS and was getting constant warnings during the ride. Noticed that tire pressure had increased to 46 PSI in rear tire and 44 in Front tire. Is this normal? And should I just adjust my threshold for warning?

Thanks

 

[ToddC]

Road heat, adjust.
T

 

[Ron]

As the tires heat up so does the air inside. Warmer air means more pressure. Honda says 36/42 (F/R) for the 1100. I don't know how high the pressure will go when riding.

 

[Sadlsor]

As I'm typically wrong, consider before you accept this: my wandering mind recalls reading that in "most" conditions, proper tire pressure accounts for about 10% change due to warmup and cool down, such that cold tire pressure should not increase by (much?) more than that when at normal operating temps.
For the ST1300, 42psi should read about 46 after they're warmed up.
If you're riding all day in Death Valley in August, that may not apply. That's not normal, for most of us.
EDIT: and why is it called FOBO TPS?
Fear Of Blow Out?

 

[mrazvi]

@ToddC @Sadlsor @Ron - Thanks for your responses. My understanding is that the TP must be 42 PSI cold both front and rear. So, do I worry about tire pressure while riding at all? or just make sure that cold tires measure at 42 PSI and adjust the threshold for warning to 46 as per Sadlsor's comment - And far from Death valley , I ride in Minnesota which is known for its warm weather

Thank you all! I'll look forward to a consensus on this and especially from owners of the FOBO TPMS.

PS. Did some research why it is called FOBO - No clues yet. Here are the details of this Malaysian company.

FOBO products get in tune with nature, by monitoring key environmental elements that interact
with our daily livings or things/loved ones:

It Scans, gathErs, aNalyses, conStrues and rEact to the surrounding stimuli;
FOBO is sensing with SENSE™

 

[caldercay]

My understanding is that the TP must be 42 PSI cold both front and rear.

Correct, as per page 226 in the [2008] owner's manual ... and that goes for pretty much any vehicle.

 

[dwalby]

Riding increases the pressure in tires due to road friction in any weather, and due to contact with the hot pavement in the summer months. If you set them cold they're good, don't worry about them hot, nobody ever did before TPMS were invented, and nobody ever had issues.

If you insist on taking a mathematical approach, just remember that the internal tire pressure is not what the gauge reads, but rather the gauge reading plus 15, because atmospheric pressure is about 15psi at sea level. So, if you have it set to 42psi cold on the gauge, the internal pressure is 57psi. If that increases by 10%, you add 6psi, not 4psi.

 

[Andrew Shadow]

Several on this forum have reported tire pressures approaching 50 P.S.I.G. after extended highway or very aggressive riding. This pressure reading means nothing other than being a curiosity. As long as your tire pressure was correct when the tires were at ambient air temperature, and they do not decrease while you are riding, you are in good shape.

Set the upper threshold high enough so that it does not display a warning or trigger an alarm and forget about it.
What you are interested in monitoring during your ride is that the tire pressures do not decrease relative to the tire pressures when you started your ride. A decrease in tire pressure during a ride indicates that there is a loss of air, which indicates the possibility of a leak.

 

[drrod]

I have seen well over 50psi (checked with a gauge) when riding at a good pace, twisty roads, hot days. Started at 42 before the ride. I checked with the gauge to make sure the TPMS wasn't way out of wack. It wasn't.
I use the TPMS to detect leaks. Pretty much ignore the upper readings when riding. Only watch for an unusual decline.
I set the limits high enough so they don't go off.

 

[Sadlsor]

This makes sense, in that I always thought the TPMS was actually designed to alert at LOW psi, to warn of a potential leak.
If set for proper pressure while cold, normal riding should not cause excitement due to higher pressures when warmed up.

 

[ST1100Y]

I have seen well over 50psi (checked with a gauge) when riding at a good pace, twisty roads, hot days.

I might have seen way more when the rear shock blew on my old '92... rear tire was almost too hot to touch... read something >60psi hot... deflated to about 50 and continued very carefully... (can't whack it much with a dancing/wandering rear end anyway... literally kneadding the tire, internal friction causing the heat...)

If you set them cold they're good, don't worry about them hot, nobody ever did before TPMS were invented, and nobody ever had issues.

Still the analogue guy, exactly what I do in the morning before take off: placing the pressure tester on, memorize what (if) is missing, top off later on a gas station...

 

[mrazvi]

Thank you all for your advice! Much appreciate your help!

 

[bdalameda]

I have seen higher than 50 psi many times on hot days. Another thing that I think contributes to tire heat on the ST1100 is that the exhaust pipe splits around the rear tire and is fairly close. I always wondered if building some kind of heat shield would reduce rear tire temperature and possible decrease wear.

 

[drrod]

My TPMS system also displays temperature. The rear is consistently 20-30 degrees higher than the front on my 1300.
May have to do more with my riding style (in slow, out fast) but it is consistent even on longer straight stretches of road. Load? airflow? actual tire construction? Don't know but it is real.

 

[Larry Fine]

My TPMS system also displays temperature.

As does mine, but only in Celsius. Converting gives my brain something to do when I'm bored.

C /5, x9, +32 = F

F -32, /9, x5 = C

 

[dwalby]

My TPMS system also displays temperature. The rear is consistently 20-30 degrees higher than the front on my 1300.
May have to do more with my riding style (in slow, out fast) but it is consistent even on longer straight stretches of road. Load? airflow? actual tire construction? Don't know but it is real.

I think others have reported this as well, partly due to the rear wheel providing the driving force, and presumably more load/friction, combined with the difference in airflow over the tire between front/rear. The front has unobstructed airflow to provide cooling, the rear doesn't.