Stuff that costs $40 isn't always that accurate FWIW - mine is about 1 psi low. Main thing is to just figure out what the offset is and remember.

 

All of my tire gages (including the electronic one) cost far less than $40, yet they're accurate (or at least all agree with each other). I'm not asking for much.

 

You cannot recalibrate the sensors, either send it back or get used to it being out a bit.
I have a cheap set on my car and with the tyres all set at 22 the monitor shows 24, but as they warm up the pressure increases a little, so I know that it is working.

 

I don't use mine for constant, accurate measurement. (Although, that would be really nice.) I use mine to warn me of a rapid deflation situation so I can slow the heck down.

 

This isn't one of those "you get what you pay for" situations, FWIW.

As far as I can tell, there's also no way to recalibrate the (far more expensive) Garmin TPMS or Fobo systems. So, I'm glad I didn't spend big coin on one of those, to get basically the same result.

 

Both my front and rear sensors read 3 pounds too high when measured against a very accurate dial gauge and 2 others.

 

That's interesting that some sets read too high and some read too low, and coincidentally, yours are off high by the same amount mine read low.

I may have defective sensors. I didn't ride to work today, but I took a quick look at the FJR before I left, and noticed that my SRTP300 was reading higher front pressure than rear (nominally should be 39 psi front, 42 psi rear) - 45 and 42. Wut?

Temperatures made no sense: 109°F and 91°F, respectively. At least those correspond to the indicated pressures somewhat.

Temperature in garage, according to wall thermometer, was all of 76°F, confirmed by "skin feel-o-meter" and consistent with weather app. I haven't ridden the FJR since Sunday, so I'm not seeing how the tires could possibly be that warm, early in the AM when it's cool.

Time to ask Sykik what's up. TPMS isn't going to be useful if it isn't even vaguely accurate.

Maybe it's been longer than I realized, and I'm due for new sensor batteries? But I thought the head unit was supposed to alert you when that's required. Need to check the order date when I have a chance.

 

The only thing I rely on mine for is - the alarm, if I have a tire going down - so that maybe I notice the alarm before it gets too low. Or when I hop on the bike - that the tires are within the realm of good and have not been leaking while sitting. Much like the sensors in my truck - really don't ever look at them when driving. (unless an alarm goes off)

Also realize that the head unit keeps showing the last pressure/temp until you start riding again and wake up the sensors So not unusual to see high pressures and temps when you wake the head unit back up

 

Maybe that's all it is. I parked the bike on Sunday after riding several hours in temps pushing 100°F. If the display stops updating once motion ceases for X minutes or similar scheme, that might explain what's going on.

 

All these Chinese systems will display (today) what the pressures/temps were when you parked the bike last. Sensors then go into sleep mode..... to wake them up, spin the wheel and wait a few minutes for the display to refresh.... I've had a few of these systems, and none of them have been spot on with my tire pressure gauges..... make note of the deviation. Ignore the temperatures, not important, more or less useless information. Alarm settings for pressure more important.

 

I must have gotten the Goldilocks set. Mine are juuussst right. Rear tire gains a few when it warms up. Front gains one or maybe two.

On a similar note:
I had some largish TPMS caps on my MC trailer last week. 12" wheels, stock stems, rolling 70 mph. I hit a very rough bridge joint and the alarm went off. Dropped from 52 to 31 in a heartbeat, but then the loss slowed as we pulled off into a truck stop.
It turns out that the very thing that saved a ton of destruction was the thing that caused the problem. The stems had a metal core, yet one cracked from the centrifugal force. Too much weight at the tip along with too much speed for those small chinese wheel assemblies. When I slowed down, it nearly sealed itself.

The moral of the story is that you REALLY SHOULD use all-metal stems with TPMS caps.

 

I'm not sure what you're saying. Are you saying a rubber valve stem ripped due to the shock of the wheel hitting the bridge joint? Or that it was a slower failure, due to high wheel RPMs (small wheel + highway speeds)?

 

It ripped. Sudden failure.

 

The theory is that the slightly heavier toms cap causes the rubber stem to fail. I don't buy it, ran rubber stems for years with heavy valve caps on trucks.

 

• These wheel assemblies are only a year old.
• The valve stems have a metal core that runs down close the rim, but not all the way through the "grommet" portion of the stem, so that may cause a weak area in these particular stems.
• The TPMS caps I used are larger and heavier than the Sykik ones we use on our bikes.
• The wheels are small, so they spin fast. = greater centrifugal force.
• The stems stick out of these rims almost parallel to the road. Not upright or at a 45° angle like most that I see on bikes.

The stem failed "outward", meaning that if you flex it away from the hub, air comes out near the base of the stem. It broke from centrifugal force coupled with inertia imposed by impact with the bumps in the road.

I slowed down to <=65mph for the rest of the trip and had no problems. I bought metal stems to install as an upgrade.

 

Ah I get that.

I've been a metal valve stem princess for years on MC wheels, always having those 83° (or whatever number it is, it's not quite a full 90°) metal stems because I found it made pressure checks and filling easier. And because they last forever. I'm sure you can re-use rubber stems too, and that many have, with success, but I like shiny things.

 

Rubber stems have no reinforcement. With age, they crack, and the cracks become leaks. Sometimes the cracks lead to "catastrophic divergence".