Page 1 of 2 1 2 LastLast
Results 1 to 15 of 21

Thread: 2010RT Air Pressure Sensors

  1. #1
    Dave Nicholls 105258's Avatar
    Join Date
    Mar 2004
    Location
    Teulon Manitoba Canada
    Posts
    154

    2010RT Air Pressure Sensors

    The tire air pressure sensors on this bike have been perfect, until my latest trip through Glacier National Park. When I got to St Mary's I noticed the tire pressures were 5 psi low so I stoped to check. Theye were fine. Now that I am home on the Canadian praries they continue to read lower than they actually are bu some 5 psi. Any suggestions ?
    Dave Nicholls
    Teulon Manitoba - Canada

    2010 1200RT

  2. #2
    A bozo on the bus deilenberger's Avatar
    Join Date
    Mar 2003
    Location
    Spring Lake NJ, USA
    Posts
    7,736
    What standard are you using to check the pressure? I have found almost all tire-pressure gages seem to drift out of calibration. The electronic ones included. Only one that has been really consistent is one attached to a tire inflater I have - from Harbor Freight. It agrees perfectly with my TPM system readout (which isn't a BMW system - it reads real pressures, not temperature compensated.)

    My basic thought is - if you find a pressure that works for you - using one gage, then ALWAYS use the same gage to check your pressure. Oh - one other thing I've noticed.. I never need to add air to my tires as long as I don't check them with an external gage. It seems just hooking up, reading, disconnecting a tire pressure gage drops the pressure 1-2 PSI on a bike tire. Not so much on a car tire since it has a much greater volume of air.

    Of course YMMV..
    Don Eilenberger http://www.eilenberger.net
    Spring Lk Heights NJ NJ Shore BMW Riders New Sweden BMW Riders
    '07 R1200R (current ride) and some bimmers.. and a Porsche

  3. #3
    na1g
    Join Date
    May 2011
    Location
    Greater Bahstin, Massachusetts
    Posts
    831
    "...hooking up, reading, disconnecting..." It's tough to get the tire gauge to seal on the valve stem without losing a little, or a lot of air. The recent R12RTs at least have that clever spoke-mounted stem that sticks out the side which is a lot easier than the usual radial-mounted one in the rear.

    Consumer Reports did a test a while back of various tire pressure guages and almost all were within a pound +/-, even some cheapies. I have three different types (round dial, electronic and pencil) and they agree exactly. The round dial has a straight chuck that is hard to get on the rear wheel stem; the electronic has a right-angle chuck that is hard to get on the front stem; the pencil gauge has a 45 degree chuck that works on both wheels.

    I don't understand the point of BMW's temperature compensated TPMS. Shouldn't I know what the real pressures are. The change in pressure from cold to warm tire is a good indicator of correct pressure settings.

    pete

  4. #4
    Dave Nicholls 105258's Avatar
    Join Date
    Mar 2004
    Location
    Teulon Manitoba Canada
    Posts
    154
    I have checked with two guages, a mechanical and and electronic and both agree , but not with the pressure sensors ?
    Dave Nicholls
    Teulon Manitoba - Canada

    2010 1200RT

  5. #5
    A bozo on the bus deilenberger's Avatar
    Join Date
    Mar 2003
    Location
    Spring Lake NJ, USA
    Posts
    7,736
    Quote Originally Posted by 105258 View Post
    I have checked with two guages, a mechanical and and electronic and both agree , but not with the pressure sensors ?
    Thing is - I can't imagine anything that would happen to change the calibration of both TPM's at the same time.. so the common factor ends up being the gages. You might try a 3rd..
    Don Eilenberger http://www.eilenberger.net
    Spring Lk Heights NJ NJ Shore BMW Riders New Sweden BMW Riders
    '07 R1200R (current ride) and some bimmers.. and a Porsche

  6. #6
    Registered User
    Join Date
    May 2007
    Location
    Western NY
    Posts
    255
    The problem could be with the TPMS receiver, since both tires show exactly the same symptoms.

    The system is made for BMW by Schrader Electronics in Northern Ireland, UK. An Email to their customer service department might get some answers.
    Karl
    2007 R1200ST

  7. #7
    Benchwrenching PGlaves's Avatar
    Join Date
    Oct 2003
    Location
    "Big Bend" TX
    Posts
    8,727
    Just because, I would deflate completely and then re-inflate each tire.
    Paul Glaves - "Big Bend", Texas U.S.A
    "The greatest challenge to any thinker is stating the problem in a way that will allow a solution." - Bertrand Russell
    http://www.bigbend.net/users/glaves

  8. #8
    Registered User
    Join Date
    Sep 2008
    Location
    Wilmington, NC
    Posts
    2,123
    I've got a VW that allows me to reset the warning limits of the TPMS it has from its dash.
    Its done simply by hitting reset after the tires are all properly inflated. So one good calibrated gauge allows an accurate reset of the car. But it doesn't read psi, thank goodness- it only shows a warning when it thinks you need air.
    From my perspective I'm not happy with this uneeded crap in my vehicles- its just another unreliable and expensive electronic piece of junk put there to protect idiots and the oblivious from themselves by a nanny govt

    Most every rental car I get that has a tpms has the warning light on. Can't wait to read about the first class action by all the folks allegedly injured in rentals with low air now that there is some visible evidence some lawyer can use to enrich himself...

  9. #9
    Dave Nicholls 105258's Avatar
    Join Date
    Mar 2004
    Location
    Teulon Manitoba Canada
    Posts
    154

    Thanks

    Thanks for your asstance. I have tried all your suggestions and I belive I have two gages that are accurate, but no change in the sensor readings. I will take the bike to the dealer next week.
    Dave Nicholls
    Teulon Manitoba - Canada

    2010 1200RT

  10. #10
    Dave Nicholls 105258's Avatar
    Join Date
    Mar 2004
    Location
    Teulon Manitoba Canada
    Posts
    154

    No Resolution

    As I suspected the actual air pressure, measured by four very accurate race guages, was four pounds higher than what was read by the TPS. The expensive guages read the same as a $6.00 Canadian Tire slide type guage by the way.

    I took the bike to the dealer who confirmed the issue. BMW's response was the same as the fuel strips, the guage is not expected to be accurate, but is meant to be a warning for a tire going flat. They never did address the issue of the apparent sudden change in accuracy of the sensor.

    For such an expensive bike you would think they would be better than that. Why would they put the readings in the computer and not just use an idiot light.

    My GM van is very accurate and I purched a set of four sensors for less than $100.00 CDN for a set of snow tires a few years back. Wonder what the BMW ones cost ?
    Dave Nicholls
    Teulon Manitoba - Canada

    2010 1200RT

  11. #11
    Registered User Atomicman52's Avatar
    Join Date
    Jun 2009
    Posts
    436
    Quote Originally Posted by 105258 View Post
    As I suspected the actual air pressure, measured by four very accurate race guages, was four pounds higher than what was read by the TPS. The expensive guages read the same as a $6.00 Canadian Tire slide type guage by the way.

    I took the bike to the dealer who confirmed the issue. BMW's response was the same as the fuel strips, the guage is not expected to be accurate, but is meant to be a warning for a tire going flat. They never did address the issue of the apparent sudden change in accuracy of the sensor.

    For such an expensive bike you would think they would be better than that. Why would they put the readings in the computer and not just use an idiot light.

    My GM van is very accurate and I purched a set of four sensors for less than $100.00 CDN for a set of snow tires a few years back. Wonder what the BMW ones cost ?
    YOu do understand the temperature compensated nature of the BMW system. Your gauge and your TPMSnly match at 68 Degrees F.

    You send set your tires with to the pressures you desire on the TPMS. and then take a reading with your gauge to determine the diffeentail between your gauge and the TPMS, and then adjust accordingly This is explained in the Owner's manual. See attachment
    Attached Files Attached Files
    Last edited by Atomicman52; 08-12-2012 at 04:02 PM.
    "The Older I Get, the Faster I Was"
    '09 Black Metallic Sapphire "Fully Farkled" RT

  12. #12
    Dave Nicholls 105258's Avatar
    Join Date
    Mar 2004
    Location
    Teulon Manitoba Canada
    Posts
    154

    Their Back !!

    Just last week on my way to Toronto, they began to work again. Now they read exactly what the tire qage reads. Go figure .
    Dave Nicholls
    Teulon Manitoba - Canada

    2010 1200RT

  13. #13
    Registered User
    Join Date
    May 2007
    Location
    Western NY
    Posts
    255
    Quote Originally Posted by Atomicman52 View Post
    YOu do understand the temperature compensated nature of the BMW system. Your gauge and your TPMSnly match at 68 Degrees F.

    You send set your tires with to the pressures you desire on the TPMS. and then take a reading with your gauge to determine the diffeentail between your gauge and the TPMS, and then adjust accordingly This is explained in the Owner's manual. See attachment
    The example in the Owner's Manual essentially states to inflate your tires so the TPMS shows the desired values. Since the TPMS shows what the pressure would be if the temperature were 68 F, the result is an under-inflated tire on cold days and an over-inflated tire on hot days. For bikes without TPMS, BMW does not provide a table of desired cold pressures versus ambient temperature. They provide only a single desired pressure. The whole temperature compensation scheme conflicts with the information provided by tire manufacturers, who are the real experts.
    Karl
    2007 R1200ST

  14. #14
    Ed Kilner #176066
    Join Date
    Nov 2011
    Location
    Mississauga, ON
    Posts
    490
    Quote Originally Posted by kthutchinson View Post
    ?..The whole temperature compensation scheme conflicts with the information provided by tire manufacturers, who are the real experts.
    Karl, can you provide a link to this tire manufacturer info?
    Ed
    2011 R1200RT Thunder Gray Metallic; 2000 Triumph 900(sold)
    http://triumphantsblog.blogspot.ca/

  15. #15
    Registered User
    Join Date
    May 2007
    Location
    Western NY
    Posts
    255
    Ed,

    Here are a few.

    Metzeler: Tire Pressures

    Continental: Air Pressure

    Maxxis: Motorcycle Tire School

    Note that none of them say anything about modifying the "cold" pressure based on outside air temperature.

    For an detailed explanation of tire physics, I recommend chapter 2 of Tony Foale's book, Motorcycle Handling and Chassis Design.
    Karl
    2007 R1200ST

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •