I occasionally see people complaining about the lack of meaningful tire comparisons. I guess they think someone should be doing comparison testing. I covered the topic of the cost of testing tires in May 2016 and even offered to run a test if there was some financial support. FYI after the offer, I received the grans total of $0.00 so I can only guess people want someone else to do the work and spend the money.
Cost aside, I'm not exactly sure what people would want or expect in an un-bias comparison.
Cost: This is difficult as there are many different outlets for tires and without some detailed research How would you establish the value of buying from a neighborhood tire store vs buying the tires mail-order. If you had a problem how would you like to have to pay to ship the problem tire back to the sales outlet vs just taking the tire to the local dealer?
Different outlets also have sales of specific sizes or type tire so a comparison of brand Q vs brand U could be very misleading if the identical size wasn't involved, and how would you compare a tire that is on sale in Calif vs one not on sale but with a free 1-year warranty in Ohio?
Wear: Now we are back to the cost associated with doing the testing, and we have already seen that apparently, no one is willing to finance this type of testing.
Durability: Again controlled testing is expensive. Even if tires were donated and you found some RV owners willing to do the testing how do you compare the durability of a set of tires driven in PA & NY vs tires on a different RV driven in TX & AZ. Would you be willing to sign up to do the driving if you had your route specified to be a 200 mile back and forth trip across Iowa on US RT 30 with the requirement to complete 1200 miles a week for ten weeks, with you paying the cost of fuel, etc?
If a reader has some specific questions or requests on what information they would expect to gain from such a comparison, My offer of setting up and overseeing the testing still stands but someone else still needs to come up with the money to buy the tires and pay for the testing.
So yes it still comes down to cost and who is willing to pay. One other thing to consider is that there is always the potential of setting up and running an expensive test only to have one of the tires being evaluates dropped from production just as you complete the evaluation.
Just think if we had somehow started a test that included the Goodyear Marathon ST tire in the fall of 2016 and it was finished a year later, only to learn the Marathon was being replaced by the Goodyear Endurance?
##RVT899
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Friday, May 31, 2019
Friday, May 24, 2019
Is a "Plug" repair or "liquid sealant" an acceptable repair?
Got a reply to a post on an RV Forum on a discussion on the use of a "plug only" type repair. I had posted a couple of pictures of examples of tires that had been run when significantly under-inflated and the owner only used a "plug-only" type repair.
Here is a picture of a tire showing the cracks through the inner liner due to the tire being run severely under-inflated because of the air leak, and run for hundreds of miles.
Here is another tire that had significant damage from the puncturing object but the damage went undetected because the tire was not dis-mounted and inspected.
Here is an example of a tire that was "plugged" 3 times but apparently continued to leak and the owner put some type of liquid sealant into the tire trying to stop the leak. (Note I don't think this is Fix-A-Flat brand sealant but you understand what I am talking about here.
Would you feel comfortable driving on either of these tires?
These examples show why the proper method of repair is to Dismount, Inspect then if the tire is OK a patch and plug and be used to seal the air chamber and to protect the steel belts from rusting due to water entering the belts from the outside. If you don't inspect how would you ever know the extent of the damage that has been done to your tires?
The person was asking the initial question about the advisability of using a plug, I assume wanted to do plug repairs continued:
"I'm still not sure what point you are making, especially if the cracks and the puncture are unrelated.
If the plug repair was successful, as most are, OR if there had never been a puncture anyway, then a tire interior would never be inspected and so cracks caused by say, running over a curb or large rock, would never be noticed unless they caused air loss that resulted in testing or inspection.
Your second exhibit shows a tire with a plug repair that we don't know if successful or not and again, probably or possibly unrelated damage that could have been there for hours or years and may or may not have been the reason for the tire being dismounted, so again, your point? Tires get damaged, tires fail and as your photos clearly show, a simple sharp object penetration isn't the most serious injury tires are subjected to."
I agree it may be "possible" to do a "plug" repair that will allow a tire to hold air. The main problem is that most people who do a plug repair as a "temporary fix" to allow them to stop the leak, re-inflate the tire and continue to travel to get off the highway. Most will never go the next step to have the interior of the tire inspected.
Innerliner cracks come from operating a tire for many hundreds of miles with the excess deflection that is probably due to running significantly underinflated. Such operation can not only damage the inner liner but also compromise the belt integrity.
Many times if there is a belt separation later, the owner does not associate the decision to not have the tire inspected and replaced if the damage is discovered so simply blames the tire MFG for the failure.
The second picture shows the damage to the interior of the tire when the object (maybe a piece of wire) was left in the tire and it cut through the inner liner. This will result in high-pressure air being forced into the body of the tire and again possibly leading to a separation that again the owner does not associate with the puncture weeks or months previous.
Some points to consider:
1. The use of a plug only will void any tire warranty according to most tire companies (GY, MI, BS, etc)
2. The use of a plug only is specifically not approved by DOT so don't try and make a claim of a tire being "defective" to NHTSA or in any court of law
3. Unless you have personally inspected a few thousand tires and can provide evidence that tires with improper repairs do not suffer secondary catastrophic failures, I suggest you include a warning with your posts that your observations are only based on your experiences with a few tires.
I agree that we are all entitled to our personal opinion but not our own facts, especially when others may be relying on our statements for the safe operation of their vehicles and specifically their tires.
Go ahead and use a plug if the situation warrants but just be sure you have the tire dismounted, completely inspect and if possible properly repaired but please be clear that without a complete inspection it is possible that the tire has suffered irreparable damage and should be removed from service.
Friday, May 17, 2019
Do your Tow Vehicle and Trailer match?
Here is some good advice I found on the Interweb and agree with.
Here is a short video from the RV Safety Education Foundation. A longer in-depth video link available at the end of this post.
You should always do your calculations based on the GVWR of the trailer, not the dry (shipping) weight. The dry weight is a number used by some manufacturers and some dealers to try to sucker people into purchasing a trailer that is too much for their truck
The same goes for tongue weight. The marketing brochure may provide the trailer weight based on the empty trailer (with no propane or batteries, etc.). You should figure your weight based on 15% of the GVWR of the trailer. But the real trailer weighs figure you should know is what the truck scale tells you once the trailer is fully loaded but not hooked to the tow vehicle.
You can not use the "paper" figures found in truck or trailer literature and certainly not the verbal information from the truck or trailer salesperson to calculate your towing capacity. You MUST have real numbers which mean actual scale weights.
Next, take the cargo capacity of your truck (from the payload sticker from the door jamb of the driver's door on the truck). It will say something like "cargo must not exceed ... lbs.". From this payload capacity, you need to be able to deduct all of the following:
- People in the truck
- Cargo in the truck
- Weight of the WD trailer hitch or of the hitch for the 5th wheel
- Total actual weight of the trailer
Then you should also consider the maximum or gross combined weight rating (GCWR) - this is the maximum weight you're allowed to have on the road, which combines the full weight of the truck and trailer combined. To get these, you can use the GVWRs of both the truck and trailer, but really you should go to the scales and have them weighed as YOUR truck and YOUR trailer almost certainly do not weigh what is shown in the literature.
When working all these numbers, you need to consider the following:
- Do I have enough truck (engine, transmission, etc.) to pull this load up and over the hills without causing undue stress on the engine/transmission, etc?
- Do I have enough truck (brakes) to stop this whole load in the event the trailer brakes fail without causing undue stress to the truck brakes?
- Do I have enough truck (suspension, tires, etc.) to control the trailer in heavy winds, while passing or being passed by semi trucks - and especially in the event of an emergency maneuver, like dodging a deer which just jumped out on the road in front of me or a tire failure (blow-out).
I hope you're getting the basic information before you purchase. You'd be way ahead of the game.
In-depth video at RVSEF web site on truck - trailer matching HERE.
##RVT897
Here is a short video from the RV Safety Education Foundation. A longer in-depth video link available at the end of this post.
You should always do your calculations based on the GVWR of the trailer, not the dry (shipping) weight. The dry weight is a number used by some manufacturers and some dealers to try to sucker people into purchasing a trailer that is too much for their truck
The same goes for tongue weight. The marketing brochure may provide the trailer weight based on the empty trailer (with no propane or batteries, etc.). You should figure your weight based on 15% of the GVWR of the trailer. But the real trailer weighs figure you should know is what the truck scale tells you once the trailer is fully loaded but not hooked to the tow vehicle.
You can not use the "paper" figures found in truck or trailer literature and certainly not the verbal information from the truck or trailer salesperson to calculate your towing capacity. You MUST have real numbers which mean actual scale weights.
Next, take the cargo capacity of your truck (from the payload sticker from the door jamb of the driver's door on the truck). It will say something like "cargo must not exceed ... lbs.". From this payload capacity, you need to be able to deduct all of the following:
- People in the truck
- Cargo in the truck
- Weight of the WD trailer hitch or of the hitch for the 5th wheel
- Total actual weight of the trailer
Then you should also consider the maximum or gross combined weight rating (GCWR) - this is the maximum weight you're allowed to have on the road, which combines the full weight of the truck and trailer combined. To get these, you can use the GVWRs of both the truck and trailer, but really you should go to the scales and have them weighed as YOUR truck and YOUR trailer almost certainly do not weigh what is shown in the literature.
When working all these numbers, you need to consider the following:
- Do I have enough truck (engine, transmission, etc.) to pull this load up and over the hills without causing undue stress on the engine/transmission, etc?
- Do I have enough truck (brakes) to stop this whole load in the event the trailer brakes fail without causing undue stress to the truck brakes?
- Do I have enough truck (suspension, tires, etc.) to control the trailer in heavy winds, while passing or being passed by semi trucks - and especially in the event of an emergency maneuver, like dodging a deer which just jumped out on the road in front of me or a tire failure (blow-out).
I hope you're getting the basic information before you purchase. You'd be way ahead of the game.
In-depth video at RVSEF web site on truck - trailer matching HERE.
##RVT897
Friday, May 10, 2019
Have you "tested" your TPMS?
Like anything mechanical or electrical, parts can die, wear out or malfunction. While I am not aware of a lot of reports of failures of TPM Monitors or sensors I would be surprised if the only problems were related to battery life or improper set-up.
This post is limited to TPMS that use externally mounted sensors. i.e. the ones that screw onto the end of your valve stem.
Batteries. They eventually will die. The early warning of loss of signal from a sensor that previously was working appears to be an occasional intermittent loss of signal, followed eventually by almost constant no signal on the display. This is easy to fix as most of these systems have user replaceable batteries. I always carry a couple but also I don't stock up as batteries may lose power even sitting in their original packaging.
"O" ring: Under the screw-on plastic cap there is a very small O-ring. As with any rubber component they can simply die ( crack or tear) just from normal use as rubber does "age-out" due to exposure to heat an Ozone in the atmosphere. I would suggest having a few "O" rings on hand as, unlike the batteries, you can't just pick up a replacement at CVS, Walmart, or Walgreens. You will probably have to get them from your TPMS dealer. When you screw the cap on the sensor don't overtighten the cap as that can distort the O-ring and shorten its life
Plastic cap. This part should last longer than the rubber O-Ring but plastic ages too. Again this is special and unique to your brand TPMS so having at least one on hand from your dealer is a good idea. Also, don't over tighten the cap. It might be possible to seal a cracked cap for a short time with Silicone seal or glue but be careful not to glue the cap to the sensor.
Sensor electronics. All you can do here is get a new replacement sensor. Some brand TPMS offer a longer-term warranty (Lifetime) others only 12 months. I do carry a spare sensor but not in my toolbox or parts box but I added a sensor to my spare tire. in my Class-C. This gives give me a replacement I could use on a ground tire if one of those sensors ever failed. It would only require a quick program change when I move the sensor from a spare position to the ground tire. I could do without a sensor on the spare for the week it might take to get a replacement sensor. The reputable dealers I have talked with all offer single sensor sales or replacement under warranty. A sensor on a spare tire would probably last longer than the other external sensors as it isn't exposed to potential strike from road debris or heat from the tire or brake drum. If I had a sensor fail I would plan on keeping the cap and O-ring if in good condition as a future spare part.
Monitor. Well if this part fails I don't know of any repair a user could do. You just need to get a new monitor from your dealer and hope you have a good warranty and that your dealer will sell the monitor by itself so you don't have to buy another complete system. I have to admit that I did manage to damage my older monitor after four years of reliable use. I grabbed the wrong power cord and connected it to a 12v source which fried the monitor that only wanted 5V. My Bad. Luckily I was able to get just the sensor and didn't have to buy a bunch of new sensors at the same time.
Replacement parts: If you bought your TPMS from a dealer that specializes in the RV market and attends RV shows then you should be able to get individual parts with little problem. If on the other hand, you purchased mail order from Amazon or eBay or similar, I have no idea what parts or service you can expect.
Testing: This is something I doubt any have done but after some consideration, I think I have an easy and workable plan.
I suggest at least once every 6 months when you are at a location where you have nice weather and a bit of time you conduct an operation test.
With the system on, I would record all the readings from for both pressure and temperature. With the Co-Pilot in the driver seat, I would go to each tire position and unscrew the sensor. The Co-Pilot should signal the tester as soon as a warning is given on the monitor. You might use your phone or walkie-talkie or maybe a 3rd person, as honking the horn as a signal might become bothersome for your neighbors. If all the sensors give a warning within a few seconds (read your manual on the claimed warning time) all is OK. If there is a delay or no warning after say 10 seconds then there may be a problem in either the sensor or monitor or programming and you MUST learn the why and take corrective action as you are depending on receiving prompt warning of air loss.
You can also use this opportunity to confirm your cold tire pressure with your calibrated hand gauge. (See THIS post on how to confirm your gauge is sufficiently accurate) and you can also "top-off your cold pressure with your normal margin of air.
##RVT896
This post is limited to TPMS that use externally mounted sensors. i.e. the ones that screw onto the end of your valve stem.
Batteries. They eventually will die. The early warning of loss of signal from a sensor that previously was working appears to be an occasional intermittent loss of signal, followed eventually by almost constant no signal on the display. This is easy to fix as most of these systems have user replaceable batteries. I always carry a couple but also I don't stock up as batteries may lose power even sitting in their original packaging.
"O" ring: Under the screw-on plastic cap there is a very small O-ring. As with any rubber component they can simply die ( crack or tear) just from normal use as rubber does "age-out" due to exposure to heat an Ozone in the atmosphere. I would suggest having a few "O" rings on hand as, unlike the batteries, you can't just pick up a replacement at CVS, Walmart, or Walgreens. You will probably have to get them from your TPMS dealer. When you screw the cap on the sensor don't overtighten the cap as that can distort the O-ring and shorten its life
Plastic cap. This part should last longer than the rubber O-Ring but plastic ages too. Again this is special and unique to your brand TPMS so having at least one on hand from your dealer is a good idea. Also, don't over tighten the cap. It might be possible to seal a cracked cap for a short time with Silicone seal or glue but be careful not to glue the cap to the sensor.
Sensor electronics. All you can do here is get a new replacement sensor. Some brand TPMS offer a longer-term warranty (Lifetime) others only 12 months. I do carry a spare sensor but not in my toolbox or parts box but I added a sensor to my spare tire. in my Class-C. This gives give me a replacement I could use on a ground tire if one of those sensors ever failed. It would only require a quick program change when I move the sensor from a spare position to the ground tire. I could do without a sensor on the spare for the week it might take to get a replacement sensor. The reputable dealers I have talked with all offer single sensor sales or replacement under warranty. A sensor on a spare tire would probably last longer than the other external sensors as it isn't exposed to potential strike from road debris or heat from the tire or brake drum. If I had a sensor fail I would plan on keeping the cap and O-ring if in good condition as a future spare part.
Monitor. Well if this part fails I don't know of any repair a user could do. You just need to get a new monitor from your dealer and hope you have a good warranty and that your dealer will sell the monitor by itself so you don't have to buy another complete system. I have to admit that I did manage to damage my older monitor after four years of reliable use. I grabbed the wrong power cord and connected it to a 12v source which fried the monitor that only wanted 5V. My Bad. Luckily I was able to get just the sensor and didn't have to buy a bunch of new sensors at the same time.
Replacement parts: If you bought your TPMS from a dealer that specializes in the RV market and attends RV shows then you should be able to get individual parts with little problem. If on the other hand, you purchased mail order from Amazon or eBay or similar, I have no idea what parts or service you can expect.
Testing: This is something I doubt any have done but after some consideration, I think I have an easy and workable plan.
I suggest at least once every 6 months when you are at a location where you have nice weather and a bit of time you conduct an operation test.
With the system on, I would record all the readings from for both pressure and temperature. With the Co-Pilot in the driver seat, I would go to each tire position and unscrew the sensor. The Co-Pilot should signal the tester as soon as a warning is given on the monitor. You might use your phone or walkie-talkie or maybe a 3rd person, as honking the horn as a signal might become bothersome for your neighbors. If all the sensors give a warning within a few seconds (read your manual on the claimed warning time) all is OK. If there is a delay or no warning after say 10 seconds then there may be a problem in either the sensor or monitor or programming and you MUST learn the why and take corrective action as you are depending on receiving prompt warning of air loss.
You can also use this opportunity to confirm your cold tire pressure with your calibrated hand gauge. (See THIS post on how to confirm your gauge is sufficiently accurate) and you can also "top-off your cold pressure with your normal margin of air.
##RVT896
Friday, May 3, 2019
Expected tire life
I Saw a question on tire life:
Generally, tire life for Bus and HD truck is based on wear, not time, as these vehicles may drive 50 to 100,000 miles a year with the tires wearing out at 50 to 80,000 miles.
Daily drivers (cars & P/U) drive about 12,000 a year and may get 3 to 5 years life again most based on wearing out.
With RVs (Trailer & Motorhome) mileage might be as low as a few hundred miles a year to a few driving up to 20,000. BUT if you consult your owner's manuals you will probably see them point out expected life to be 3 to 5 on trailers. Motorhomes probably hit 7 to the suggested max of 10 years, again before wear-out due to low miles driven in most cases.
The primary reason for the earlier "end of life" on trailers is the result of the unique radial belt shear forces identified in this blog and in the industry technical papers as "Interply Shear" that comes from a combination of tires being dragged rather than steered around corners and tires "fighting" each other when going around corners as the tires on different axles are not all rotating around the same center of the turn. It is the Interply Shear that initiates the cracks between the belts and accelerated the crack growth that can end up as a belt separation before the tires wear out. The Interply Shear damage is augmented by damage from improper (low) inflation, improper (high) load and in some cases, excess heat due to speeds higher than the basic design called for.
I hope this helps others why we have different tire life experiences on our RVs than with our cars.
##RVT895
Generally, tire life for Bus and HD truck is based on wear, not time, as these vehicles may drive 50 to 100,000 miles a year with the tires wearing out at 50 to 80,000 miles.
Daily drivers (cars & P/U) drive about 12,000 a year and may get 3 to 5 years life again most based on wearing out.
With RVs (Trailer & Motorhome) mileage might be as low as a few hundred miles a year to a few driving up to 20,000. BUT if you consult your owner's manuals you will probably see them point out expected life to be 3 to 5 on trailers. Motorhomes probably hit 7 to the suggested max of 10 years, again before wear-out due to low miles driven in most cases.
The primary reason for the earlier "end of life" on trailers is the result of the unique radial belt shear forces identified in this blog and in the industry technical papers as "Interply Shear" that comes from a combination of tires being dragged rather than steered around corners and tires "fighting" each other when going around corners as the tires on different axles are not all rotating around the same center of the turn. It is the Interply Shear that initiates the cracks between the belts and accelerated the crack growth that can end up as a belt separation before the tires wear out. The Interply Shear damage is augmented by damage from improper (low) inflation, improper (high) load and in some cases, excess heat due to speeds higher than the basic design called for.
I hope this helps others why we have different tire life experiences on our RVs than with our cars.
##RVT895
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