Tire Pressure Monitor

Slk

Joined
Aug 23, 2019
Messages
82
Location
Los Angeles
Bike
2004 ST1300 ABS
Anyone installed a tire pressure monitor on the ST1300? Any recommendation? I tried the twist on sensors (that just screw on the valve) but the accuracy is not satisfying. And it causes leaks from the valve. I'd prefer the internal sensors but can't find anything that's reputable/reliable.
 
I went with metal "T" valves from Hawkshead, and the Cyclops TPMS system with screw-on sensors. "T" valves allow you to adjust pressure without removing sensors. TPMS has always been within 1# of my gauge. Who's to say which is more accurate?

I'm sure someone makes a sensor that can be mounted inside the tire but I've never looked.
 
I have external sensors on two bikes. No problems with leakage of air. Zumo 390 on my Goldwing and TireGard on the ST. I have the aforementioned T valve stems on the ST and will be changing the GW over to them when I change tires. There is always going to be a little loss of air from a tire over time due to temperature variations. I am not aware of internal sensors for a motorcycle wheel. But with a little searching, one can always learn something new. https://www.amazon.com/TireGard-13-325-33-Motorcycle-Internal-Monitoring/dp/B00DNKPKMM
 
I bought the Garmin tire pressure sensors that work with my Zumo 590. Not cheap, but very accurate (to the tenth of a PSI) and well thought out software. You set the target pressure (e.g. 42 PSI), and also decide for yourself what differential below that you want a warning at. I chose 38 PSI as the warning threshold to avoid spurious warnings caused by cold mornings.

I've had this system for a couple of years and am very happy with it.

Michael
 
If you were to receive a warning on a cold morning, would you put more air in the tires? Or, would you not, knowing that after a few miles the warning would go away as the tires warm up?
Inquiring minds want to know.
 
If you were to receive a warning on a cold morning, would you put more air in the tires? Or, would you not, knowing that after a few miles the warning would go away as the tires warm up?
Inquiring minds want to know.
Funny you should ask. I just aired up my tires this afternoon, first time since mounting new tires, T-stems, and TPMS.

They were reading lower than usual, being the first cool week this week. I aired up to 35psi front, 38psi rear.

The specified pressure is intended to be at cold tire temperature, so to answer your question, with the weather cooling, yes.
 
If you were to receive a warning on a cold morning, would you put more air in the tires?
No, not if I knew that I had correctly set the tire pressure for the prevailing daily average temperature.

For example, let's say that the average daytime temperature where I am riding is 22°C (72°F), but when I wake up in the morning and go out to the bike, the bike is cold-soaked from sitting overnight and the air temperature is 10°C (50°F). The previous day, I had inflated the tires to 42 PSI (let's assume the tires are perfect and don't leak). If I measure the pressure first thing that cold morning, it's going to be lower than 42 PSI - perhaps 39 PSI. I would not add air because as soon as I start riding, the tire pressure is going to rise by about 4 PSI due to heat generated by the tire flexing.

Come noon hour, the prevailing air temperature has risen to the forecast daily high of 22°C (72°F), and I'm hungry, so I pull off the highway at a nice restaurant. If I was to measure the pressure at that moment, it would probably be about 46 PSI. But when I return to the bike after a leisurely 1 hour long lunch, the tires and wheels will have cooled down to match the ambient temperature of 22°C (72°F), and if I was to then measure the pressure, it would be bang on specification at 42 PSI.

My experience has been that altitude doesn't have much of an effect on tire pressure - for example, riding from central Switzerland at 1,200 foot elevations up into the mountains at 4,000 foot elevations - although increasing altitude should result in increasing tire pressure because the pressure inside the tire is differential to ambient pressure. But, significant ambient temperature changes (think summer to fall, or riding from Arizona up to northern Canada in late summer) will result in a 3 or 4 PSI difference in measured tire pressure.

The short answer: if the tires were perfect and never leaked, I would adjust pressure spring to summer, and summer to fall in order to maintain the target of 42 PSI, but I would not adjust pressure on a daily basis due to daily temperature variations.

Michael

PS: An interesting anecdote - before I retired, one of the jobs I had to do at work was deliver brand new aircraft to customers. If the customer was in Europe, Africa, or the Middle East, I would fly a polar route from Vancouver Island to the destination. The first few times I did this, I left Vancouver Island (typical temperature 22°C (72°F) most months of the year) and flew up to the high Arctic the first day, where sometimes the night-time temperature would drop as low as -20°C (-4°F). Every time I did this, I would arrive at the airport in the morning and the damn plane would have two flat main tires.

Finally, after the 3rd time this happened, I figured out what the cause was: the wheel was aluminum, but the valve stem was steel. The aluminum wheel and the steel valve stem cooled and contracted at different speeds, and the tires kept going flat due to leakage at the valve stem. The solution was to tell the Quality Control guys in the factory to tighten the nut holding the valve stem in place to a slightly higher torque than the manufacturer specified - this increased the compression on the rubber washers on the valve stem, and put an end to the "flat tires in the morning in the Arctic" problem. It ain't no fun to try to thaw out and then re-inflate a frozen flat tire!

I also learned to inflate the main wheel tires to about 10 PSI over specified pressure before I left Vancouver Island, in order to ensure the tires were at specified pressure when I transited through the Canadian Arctic and Greenland in the winter.

Darn Temperature Differences...
(the orange blanket is around the tire because I was using a Herman Nelson heater to try and thaw out the tire so I could re-inflate it)
Caverton 864 Ferry 081.jpg
 
Last edited:
Michael, you have a storybook life... I love it!

I use Hawkshead t-valves and a Chinese “Spy” brand External TPMS kit I bought from a Canadian distributor on eBay. It shows front and rear external temperature as well as tire pressure.

No leaks and it’s within 1# of my master guage as well.
 
No, not if I knew that I had correctly set the tire pressure for the prevailing daily average temperature.

For example, let's say that the average daytime temperature where I am riding is 22°C (72°F), but when I wake up in the morning and go out to the bike, the bike is cold-soaked from sitting overnight and the air temperature is 10°C (50°F). The previous day, I had inflated the tires to 42 PSI (let's assume the tires are perfect and don't leak). If I measure the pressure first thing that cold morning, it's going to be lower than 42 PSI - perhaps 39 PSI. I would not add air because as soon as I start riding, the tire pressure is going to rise by about 4 PSI due to heat generated by the tire flexing.
That might change my answer, but when the weather changes, and the prevailing temps drop, the pressure should be adjusted.
 
Every time I did this, I would arrive at the airport in the morning and the damn plane would have two flat main tires.
:eek1: :eek1: :eek1: :eek1: :eek1: ! So this begs some explanation! What kind of aircraft and how tires and many main tires weren't flat?
 
I use Hawkshead t-valves and a Chinese “Spy” brand External TPMS kit I bought from a Canadian distributor on eBay. It shows front and rear external temperature as well as tire pressure.
Same parts here, the Hawkshead tee valve stems and the Spy TPMS system. I have the same Spy TPMS on my Nighthawk 750, has worked well for years.

I know how to convert between F and C temps in my head, so the C temp readings don't throw me.

I keep the display plugged in and powered from a power outlet with dual USB ports (TPMS and phone) and lighter socket (Garmin GPS traffic antenna/power cord).
 
This is the one I have:

s-l640.jpg
 
No, not if I knew that I had correctly set the tire pressure for the prevailing daily average temperature.

For example, let's say that the average daytime temperature where I am riding is 22°C (72°F), but when I wake up in the morning and go out to the bike, the bike is cold-soaked from sitting overnight and the air temperature is 10°C (50°F). The previous day, I had inflated the tires to 42 PSI (let's assume the tires are perfect and don't leak). If I measure the pressure first thing that cold morning, it's going to be lower than 42 PSI - perhaps 39 PSI. I would not add air because as soon as I start riding, the tire pressure is going to rise by about 4 PSI due to heat generated by the tire flexing.

Come noon hour, the prevailing air temperature has risen to the forecast daily high of 22°C (72°F), and I'm hungry, so I pull off the highway at a nice restaurant. If I was to measure the pressure at that moment, it would probably be about 46 PSI. But when I return to the bike after a leisurely 1 hour long lunch, the tires and wheels will have cooled down to match the ambient temperature of 22°C (72°F), and if I was to then measure the pressure, it would be bang on specification at 42 PSI.

My experience has been that altitude doesn't have much of an effect on tire pressure - for example, riding from central Switzerland at 1,200 foot elevations up into the mountains at 4,000 foot elevations - although increasing altitude should result in increasing tire pressure because the pressure inside the tire is differential to ambient pressure. But, significant ambient temperature changes (think summer to fall, or riding from Arizona up to northern Canada in late summer) will result in a 3 or 4 PSI difference in measured tire pressure.

The short answer: if the tires were perfect and never leaked, I would adjust pressure spring to summer, and summer to fall in order to maintain the target of 42 PSI, but I would not adjust pressure on a daily basis due to daily temperature variations.

Michael

PS: An interesting anecdote - before I retired, one of the jobs I had to do at work was deliver brand new aircraft to customers. If the customer was in Europe, Africa, or the Middle East, I would fly a polar route from Vancouver Island to the destination. The first few times I did this, I left Vancouver Island (typical temperature 22°C (72°F) most months of the year) and flew up to the high Arctic the first day, where sometimes the night-time temperature would drop as low as -20°C (-4°F). Every time I did this, I would arrive at the airport in the morning and the damn plane would have two flat main tires.

Finally, after the 3rd time this happened, I figured out what the cause was: the wheel was aluminum, but the valve stem was steel. The aluminum wheel and the steel valve stem cooled and contracted at different speeds, and the tires kept going flat due to leakage at the valve stem. The solution was to tell the Quality Control guys in the factory to tighten the nut holding the valve stem in place to a slightly higher torque than the manufacturer specified - this increased the compression on the rubber washers on the valve stem, and put an end to the "flat tires in the morning in the Arctic" problem. It ain't no fun to try to thaw out and then re-inflate a frozen flat tire!

I also learned to inflate the main wheel tires to about 10 PSI over specified pressure before I left Vancouver Island, in order to ensure the tires were at specified pressure when I transited through the Canadian Arctic and Greenland in the winter.

Darn Temperature Differences...
(the orange blanket is around the tire because I was using a Herman Nelson heater to try and thaw out the tire so I could re-inflate it)
Caverton 864 Ferry 081.jpg
Using air or nitrogen?
 
There is an internal option.

I'm using the Orange M202 with internal sensors. Had it on 2nd bike now. Works great and as far as I know dead on accurate on internal temperature and pressure.
 
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