TPMS accuracy??

Discussion in 'GS Boxers' started by duckboy, Nov 24, 2012.

  1. duckboy

    duckboy Been here awhile

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    I thought my air gauge were accurate all this time until I got my '12 gs triple blk with TPMS. Now it looks like my air pressure gauges have been short (gives a value greater than the TPMS) by 2-3 psi. anyone known how accurate the TPMS is to begin with?
    #1
  2. daesimps

    daesimps Adventurer

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    Remember that the TPMS gives a temperature calibrated reading. It compensates for the temperature of the air and gives you the what the pressure would be at 20 Degrees C (since these are the reference pressures/temperatures in the manual).

    Your normal gauge will not do this and gives you the pressure of the tyres at the current temperature.
    #2
  3. rmarmbruster

    rmarmbruster Roba

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    Not trying to be a clever but you can check your tyre pressure gauge against the TPMS: (P1*V1/T1)=(P2*V2/T2). Obtaining the tyre temp may be the challenge but I can think of a couple of ways, loose some air onto a mercury bulb thermometer and calculate using both pressures to see if it is the same region.

    I could be fun figuring this one out.

    Cheers

    Rob A
    #3
  4. Ridestrong

    Ridestrong Been here awhile

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    Ok, without going into all the scientific calculations, what is the best approach to reading your pressure, assuming you have both? I'm thinking just go with whatever the air gauge says and realize the TPMS will show temp. related calculations. My purpose would be to make sure I'm not losing air while traveling. This can be done with the TPMS, just by being able to monitor constantly, along with the alarm light, even if it doesn't agree with the standard air gauge because of temperature.

    I've been strongly considering adding a TPMS to my bike. My BMW dealer caries the Orange brand. Is there any consensus which one is best or most preferred? I know there have been other threads about this but it's been awhile and some brands have discontinued motorcycle applications and/or gone out of business. Are there any that will actually show that your pressure is low before you get rolling?
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  5. jzeiler

    jzeiler ADWrencher

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    Usually NO. It is the centripital force of rotation that turns on the sending units. Other wise they would be transmitting data (and consuming battery power) when parked.

    I have heard good things about the Orange TPMS but thought they too had gone under, maybe just some bad info (yup bad info they are still out there). I run the older SmarTire system on both bikes but it is getting harder to find transmitters.
    #5
  6. sbk12rs

    sbk12rs Buddy in Training

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    I think these tpm's are a silly " GADGET " for the yuppie rider that just needs gadgets .

    AND to make these silly posts .


    just sayin .........

    Flame away yuppie riders
    #6
  7. CrustyAPO

    CrustyAPO Been here awhile

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    I would have to disagree. Yes, they are another "gadget", but a useful one. After a 5500 mile trip out west using Orange Electronic tpms system, it was nice being able to see tire pressures at a glance. I carried my manual guage with me as well and found after a few times of double-checking the tpms that it was redundant. The Orange Electronic system display changes from blue to red when either the tire pressure or temp go outside the limits you set. Kind of like the big red "OIL" light the stock and drag car drivers use on their steering columns to warn them of low oil pressure. So I didn't have to actually have to see the numerical readout, just the color change to get my attention. I didn't have any tire troubles while on my trip but if I had a puncture or a slow leak I would have been made aware of it long before it could cause trouble (catastrophic failures tend to make themselves know immediately). So while it might seem like one of those frivilous gadgets people add onto their motorcycles, I feel it is as useful as extra driving lights, a voltmeter, or a side stand foot enlarger.
    #7
  8. Twempie

    Twempie Been here awhile

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    My bike came with the OEM yuppie device.

    Last summer, 2-1/2 weeks on the road, ability to check air pressure many times a day, comparing with daily "manual" gauge-check. Priceless.

    Daily commute, ability to easily check air pressure every morning and evening. Priceless.

    Recognizing the differences between what's displayed on the computer and the air gauge. Enlightening.

    Every time I ride the bike... I check my tires. I just love this yuppie device.
    #8
  9. flyrodder

    flyrodder Donny, please.

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    I guess you can add TPMS to ABS as a "yuppie device". Whatever. When I'm two-up with either of my kids or my wife it is a great thing to be able to take a quick look down and see what the pressures are. TPMS has saved me from at least one "oh-shit" moment; on the CDT in southern Montana out in the middle of bleeping noplace -- the warning light caught my attention (at a higher-than-I-should-have-been-riding-speed) and allowed me to get slowed down well before the tire completely deflated.
    #9
  10. Dan-M

    Dan-M Long timer

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    I don't know if I would have chose TPMS but the bike was equipped that way when I bought it. Having it is quite useful. Being able to check the pressure on the fly when there is a question is quite handy.

    Those who would never have it better rethink that. It is only a matter of time before it is law like on cars.
    #10
  11. erkmania

    erkmania Last of the red hot left pipers

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    Saved my ass, once! Perhaps your ass doesn't need saving...
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  12. Twempie

    Twempie Been here awhile

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    :freaky
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  13. Pappy541

    Pappy541 Been here awhile

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    I have had 3 rear flats on my 09 GSA in 98,000 miles. It is fantastic when the warning light comes on and you can pull over and check it out before you ruin a tire, wheel or your ass. Once I was fully loaded with camping gear on a dirt road. It is much easier to put that loaded big boy on the center stand when there is still some air in it. Then after you plug it you can monitor it to make sure it is holding pressure.
    #13
  14. lkchris

    lkchris Albuquerque

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    TPMS exists because a few years ago Ford Explorers with Firestone tires experienced an inordinate number of rollover accidents.

    The response was the Federal requirement that TPMS systems be fitted on all 2007-on production cars sold in the USA.

    And you can now optionally have it on some BMW motorcycles.

    The purpose of the systems is to warn of dangerously low tire pressures.

    Their purpose is not really to provide a readout of your tire pressure, but instead notification that it's significantly lower than desired.

    Anything to do with "yuppieness" is inane at best, but then consider the source ... pee pee problems being of no interest here.
    #14
  15. Twempie

    Twempie Been here awhile

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    sbk12rs got the reaction he wanted and is probably having a wank about it right now.
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  16. Chip Stevens

    Chip Stevens Been here awhile

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    I picked up a nail south of Willcox Az. Temp was 36 degrees (I know I have another Yuppie device a Thermometer). It was raining and an occasional snow flurry. It was nice to be able to keep an eye on the tire pressure that lonely cold night. Thank God for Yuppies.
    chip
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  17. duckboy

    duckboy Been here awhile

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    twempie,

    didn't know the stk tpms system was so sophisticated. i thought i just an absolute pressure. again, thanks for the helpful and relavent info.

    duckboy

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  18. duckboy

    duckboy Been here awhile

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    Chip,

    i'm not a yuppie either but would have to agree that these options on the bike are not necessary but sure come in helpful under certain conditions. kind of like heated seats. don't really need them, but, when you do, they sure are NICE :evil :D

    and yes, thank goodness for yuppie driven marketing!! :)

    thanks!

    #18
  19. Twempie

    Twempie Been here awhile

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    :lol3
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  20. rmarmbruster

    rmarmbruster Roba

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    I would not mind having TPMS but would consider it behind other options and it won't put air in the tyres for you. It's best to get tyre pressures correct before leaving home when the tyres are at garage storage temp. Lots of arguments for and against. It has some merit for 4 wheel drivers towing a trailer and the like or even adventure riders on and off the black top through sand and mud etc in one outing. It can help remind at a glance what tyre pressure is running to help stay out of trouble.

    Just my two bobs worth.


    Cheers
    #20