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CVO Technical => Wheels/Tires/Suspension/Brakes => Topic started by: ZVO on February 16, 2017, 09:55:06 PM

Title: Tire pressure system
Post by: ZVO on February 16, 2017, 09:55:06 PM
Sucks...always malfunctions, never reads correctly why would Harley install sucks a inferior system?
Title: Re: Tire pressure system
Post by: SDCVO on February 16, 2017, 10:27:17 PM
Mine has been dead on,  no issues
Title: Re: Tire pressure system
Post by: bigchuck on February 17, 2017, 12:09:46 AM
Sucks...always malfunctions, never reads correctly why would Harley install sucks a inferior system?

Habit
Title: Re: Tire pressure system
Post by: Phreakyz on February 17, 2017, 06:34:13 AM
Mine has been dead on,  no issues

Mine works great - One of my favorite options on the bike.   Makes me feel much safer!

Whats the history of your bike?    Tires been replaced?   Running Nitrogen instead of O2?  Anything else that might have affected the system?   Also Electronics could potentially interfere with the signals from the Tire Pressure Monitors...   Any accessories that might be transmitting RF and interfering?   There are also batteries in the TPMS Sensors in the Valve Stems that periodically need to be replaced.


Title: Re: Tire pressure system
Post by: FLSTFI Dave on February 17, 2017, 07:59:48 AM
Mine reads one pound low on both front and rear from my trusty gage.  I really like the system, much easier to check pressure.  Also easy to keep and eye on pressure.
Title: Re: Tire pressure system
Post by: grc on February 17, 2017, 08:36:46 AM
Sucks...always malfunctions, never reads correctly why would Harley install sucks a inferior system?

What does your dealer and H-D have to say about it?  Have you taken the bike in and insisted they fix it?

Many people have claimed theirs works great, so I'd guess there is something wrong with your particular parts OR something else is interfering with it's operation.  And there have been a few reports of defective wheel sensors having to be replaced almost immediately.  If I've learned nothing else about Harley, I've learned they never have a smooth and seamless launch of "new to them" technology, even though it's actually old technology in the auto world.

Jerry
Title: Re: Tire pressure system
Post by: ultrafxr on February 17, 2017, 08:46:23 AM
Mine works great. Very nice to be able to check pressure so easily.  Like others have said something is faulty in your system. Hopefully easy to remedy.


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Title: Re: Tire pressure system
Post by: KGB on February 17, 2017, 09:09:12 AM
Habit
Being in the auto industry for years, I have noticed that a lot of people do not understand how they work, I have had people tell me that when the low TPM came on, they looked at the tire and said it doesn't look low??? Also tire pressure changes with temperature, so if your TPM light is on when you first start out, it may go off as the tire heats up, the best advise is set the tire pressure to spec when cold and check it with a known good tire gauge (they all are not as accurate as you think) if after that then I would contact the dealer as GRC recommends, I have not had any issues with mine, it seems to be functioning as designed.     
Title: Re: Tire pressure system
Post by: ZVO on February 17, 2017, 01:28:55 PM
Mine works great - One of my favorite options on the bike.   Makes me feel much safer!

Whats the history of your bike?    Tires been replaced?   Running Nitrogen instead of O2?  Anything else that might have affected the system?   Also Electronics could potentially interfere with the signals from the Tire Pressure Monitors...   Any accessories that might be transmitting RF and interfering?   There are also batteries in the TPMS Sensors in the Valve Stems that periodically need to be replaced.

Stock, I've seen it read upwards to 45 psi on a hot day.
Title: Re: Tire pressure system
Post by: ultrarider123 on February 17, 2017, 01:46:58 PM
Stock, I've seen it read upwards to 45 psi on a hot day.

What's are your cold psi numbers?  The pressure is gonna rise once they start rolling...friction and physics...which is why the tire pressure posted on the sidewall is max load PSI, cold.  I'm not attempting to give you a science lesson here but that may be what's happening...  :nixweiss:

My '15 doesn't have the factory TPS but I installed the Fobo fobs and app.  I still check manually but the electronic devil is very handy at times.  I keep them at 38 fr, 40 rear.  I can see 42 fr and 45 rear after riding it a bit.  Once the tires cool down, I get pretty much back to 38 and 40. 
Title: Re: Tire pressure system
Post by: Phreakyz on February 17, 2017, 03:25:19 PM
What's are your cold psi numbers?  The pressure is gonna rise once they start rolling...friction and physics...which is why the tire pressure posted on the sidewall is max load PSI, cold.  I'm not attempting to give you a science lesson here but that may be what's happening...  :nixweiss:


Yep -    You should always check tires PSI cool (before you ride) because the Air expands as you ride and the tire gets hot.
Title: Re: Tire pressure system
Post by: grc on February 17, 2017, 04:40:48 PM

A good rule of thumb is a one psi increase or decrease for every ten degree Fahrenheit change in temperature.  This is why it's very important to check and adjust cold inflation pressures whenever the ambient conditions change significantly.  If you inflate your tires to the recommended cold pressure when it's 80°F outside, then have a severe cold front come roaring through, you will find your tires severely underinflated.  On the flip side, if you start out at 30°F and a big heat wave comes through, your tires will be overinflated.  Either under or over can create safety issues.

It is perfectly normal for those TPMS readings to increase as the tires heat up during operation.  Once again, verify with a known accurate gauge if you believe your system is giving you bogus readings.  Having TPMS doesn't mean you can throw away your gauges, you still need to do old fashioned inflation checks and tire inspections.

Jerry
Title: Re: Tire pressure system
Post by: Twolanerider on February 17, 2017, 06:18:07 PM
A good rule of thumb is a one psi increase or decrease for every ten degree Fahrenheit change in temperature.  This is why it's very important to check and adjust cold inflation pressures whenever the ambient conditions change significantly.  If you inflate your tires to the recommended cold pressure when it's 80°F outside, then have a severe cold front come roaring through, you will find your tires severely underinflated.  On the flip side, if you start out at 30°F and a big heat wave comes through, your tires will be overinflated.  Either under or over can create safety issues.

It is perfectly normal for those TPMS readings to increase as the tires heat up during operation.  Once again, verify with a known accurate gauge if you believe your system is giving you bogus readings.  Having TPMS doesn't mean you can throw away your gauges, you still need to do old fashioned inflation checks and tire inspections.

Jerry

Unless you inflate with nitrogen (especially Screamin' Eagle NitroChromeGentm).  That chit is perfectly stable in any environment, perfectly resists all ambient variation and deflects all tire permeability. 
Title: Re: Tire pressure system
Post by: ZVO on February 17, 2017, 08:17:38 PM
Went to the dealership and Using a tire gague the tech said my front tires were at 36 psi...and it read 45 on the digital screen. He said the valve stems constantly malfunction causing it to read wrong.
Title: Re: Tire pressure system
Post by: 1roadking on February 18, 2017, 07:49:12 AM
Mine have worked great so far. My problem is my front tire actually looses air and they can't find a leak lol. Your pressure will change after riding and when the outside air temp fluctuates a lot. It sounds like you have a faulty TPM sensor that needs to be replaced. It should be a warranty item.
Title: Re: Tire pressure system
Post by: grc on February 18, 2017, 09:05:06 AM
Went to the dealership and Using a tire gague the tech said my front tires were at 36 psi...and it read 45 on the digital screen. He said the valve stems constantly malfunction causing it to read wrong.

There were reports of that problem some time back, but many others since then have had no problem.  The dealership needs to replace the defective wheel sensors. 

Btw, I still haven't seen any official information about using tire balancing fluids or beads, but I'd caution anyone planning to use such products in tires equipped with TPMS sensors to rethink their plans.

Jerry
Title: Re: Tire pressure system
Post by: FLSTFI Dave on February 18, 2017, 09:25:33 AM
Stock, I've seen it read upwards to 45 psi on a hot day.

If its ambient temp of 70 when I air my tires cold at the correct pressures after riding the interstate or the curves hard mine will show 43~45.  Not a surprise as the air in the tire heats up, the pressure increases.  This is why everything says to check and set tire pressure cold.
Title: Re: Tire pressure system
Post by: Trigger-Man on March 12, 2017, 12:15:08 PM
A good rule of thumb is a one psi increase or decrease for every ten degree Fahrenheit change in temperature.  This is why it's very important to check and adjust cold inflation pressures whenever the ambient conditions change significantly.  If you inflate your tires to the recommended cold pressure when it's 80°F outside, then have a severe cold front come roaring through, you will find your tires severely underinflated.  On the flip side, if you start out at 30°F and a big heat wave comes through, your tires will be overinflated.  Either under or over can create safety issues.

It is perfectly normal for those TPMS readings to increase as the tires heat up during operation.  Once again, verify with a known accurate gauge if you believe your system is giving you bogus readings.  Having TPMS doesn't mean you can throw away your gauges, you still need to do old fashioned inflation checks and tire inspections.

Jerry
Excellent advice Jerry. Curious to know if there's a similar rule of thumb for altitude? If I have 40 psi at sea level, wouldn't the tire pressure read higher at 4700' elevation where the air in the tire expands :nixweiss:?
Title: Re: Tire pressure system
Post by: grc on March 12, 2017, 12:28:38 PM

Approximately 0.3 psi for every 500 foot change in altitude.

Jerry
Title: Re: Tire pressure system
Post by: Trigger-Man on March 12, 2017, 01:20:20 PM
Approximately 0.3 psi for every 500 foot change in altitude.

Jerry
Thanks Jerry :2vrolijk_21: