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    Akron, OH
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    Genealogy, Travel out West. Tires
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  1. I have covered this in a few different posts on my blog but to put it all in one place. 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 RV (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 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 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.
  2. short answer is yes as long as the compressor can generate a pressure above the pressure needed.
  3. "Operated" would normally mean driven on. BUT It is also possible to not drive at all and have a dangerous situation if you try and reinflate. A tire is OK when you park it but after checking the air pressure the Rv is parked for a few weeks but the valve core was leaking so the tire lost all its air. This would probably kink the steel body ply which could lead to a "Zipper" failure when re-inflated. Sorry, but there are not always simple answers to what seems to be a simple question. You do know that the paper clip is simply an example of how fatigue can fail steel when simply tension loading does not.
  4. I did a post on making your own air dryer with parts from Harbor Freight. Be sure the desiccant is rated for the air pressure you need. Some are only good for 50 or 90 psi. There is a 150 psi unit on eBay
  5. I believe it is reasonable to do the 7 year inspection after 7 years of use. I thought I did look at the cost per year. The OP could have paid $900 for newer tires and after 7 years paid the $1080 for 3 more years and then need new tires for a total cost $648 a year ($900 x6 + $1080)/10 or Spend the $700 per tire and after 7 years needed new tires. Cost per year ($700 x 6)/7 = $600 a year If we set aside the hassle what if you were offered 6 tires at $200 ea but knew you could only use them for 3 years then had to scrap them ($200x6)/ 3 = $400 a year cost. or am I missing something?
  6. Ray, I have a new seminar with a focus on trailer application which has different issues than when on motorhomes. Come on up to Minot and sit in.
  7. The videos were intended to demonstrate the level of force in an inflated tire. Yes they are special set-ups but failures just like these have happened but without a camera running or safety cage and with a real person who actually died instead of a dummy The steel in a tire sidewall can fail just as a paperclip can from excessive flexing. Ya how much is excessive? I don't know. I just did a test on a paperclip. One bend in one direction was enough for it to "fail". The question of how "Flat" is "too-flat"? or how far is too far has an infinite number of answers as there are an infinite number of combinations of load, speed, inflation plus the age and use of the tire and the number and size of potholes hit. Anyone care to bet $10 on exactly how many times I can flex or bend a paperclip before it fails? See me at Minot I learned in my 40 years as a tire engineer that if it is possible for someone to do something involving tires the wrong way, someone will. Sorry that I can't post a video of what can happen with every different situation. The intent of the video was to demonstrate the amount of force involved. Maybe this is a better video showing what a "Zipper" failure is. I may tend to err on the "safe-side" but experience has taught me that even when you tell someone to do or not do certain things and they decide they know more than you do, they are still happy to sue if they get hurt. I have spent too many hours in Deposition or reviewing data as an Expert Witness to not to be very careful when offering advice. Think of the hundreds of posts on RV forums where people have posted " Tire blewout for no reason" when in fact the reason was the combination of conditions when they were using the tire. OK, getting off my soapbox now.
  8. Did you ask when the warranty clock started ticking? It might be based on date of sale which means you definitely want to keep the receipt as proof. Was it a bad deal? You saved 22% which is about 1/5 of the price. If you assume 10 year life max then if you get 8 years use you got a reasonable deal. Do the rest of you agree with my analysis?
  9. I have a blog post I wrote in 2015 just on this topic. You might find answers to other tire, valve, TPMS, Load or inflation question on the Blog
  10. Some things thing to remember when considering inflating your 19.5 or 22.5 or any tire with Load Range greater than E or ANY steel body tire. You should never re-inflate a tire that has been operated "Flat" Flat means after losing 20% of the minimum inflation needed to carry the load. I would also recommend considering that if you had one dual go flat and drove on its companion, the companion is now suspect and potentially dangerous. I cover this in my seminars on tires and mention injuries that have occurred by not using an approved safety cage. You really do not want to be anywhere near a tire when it goes "Bang"
  11. tireman9

    Hankook Tires?

    OOPS I didn't know about your reply. I will admit that 99% of my Ride & Noise evaluations were on Passenger, LT & Race tires and only Heavy Truck was on Bias tires in early 70's. Whileit is true that more tread often provides softer ride in Pass & LT tires I'm not so sure about the effect once you have 100 psi in the tire. Now if you are looking at the literature from a single tire company and they offer "better ride" as a "benefit" that might be true but I don't think I have seen a direct statement identifying the "better than what". Comparing brands would be even more difficult. I am checking with a couple of other engineers who have more experience than I do on larger size tires. I will start a new topic if / when I get some data.
  12. RV Speed rating. IMO there are a variety of reasons to have a max speed rating with the primary being safety. A quick search of the Internet finds many sources identifying the stopping distance of cars and trucks. Here is a summary. Braking Power/Stopping Distances for a car. Note that the 80 MPH distance is 130% of what it is at 50 mph Bus & trucks take 50% to 70% more distance at 50 mph, so you could be looking at almost two football fields to stop your Class-A. Some may not want to worry about stopping distance, or how many cars they would drive right over in an emergency but clearly, tires will get hotter at 80 than at 70 and with heat being the primary killer of tires you could be shortening tire life by a year or two but most importantly you would get no advance warning as the damage to the rubber strength is buried deep inside the tire structure. Also, don't know why anyone would want to see a 10 to 20% increase in fuel costs. Do I need to research an article for FMCA mag? Speed Thinking Distance Total Stopping Distance 50 mph 50 feet (15 m) 175 feet (53 m) 60 mph 60 feet (18 m) 240 feet (73 m) 70 mph 70 feet (21 m) 315 feet (96 m) 80 mph 80 feet (24 m) 400 feet (120 m
  13. Reasonable idea Bill, I'm checking on it. I will admit I have not reviewed the info FMCA gives out on our tire program.
  14. Why is it so difficult for folks to understand that when a tire with a stated max speed of 65 is not appropriate for normal RV use? Whoever decided to put the Goodyear G159 on an RV was not a competent tire person IMO. RV tires should clearly state Long Haul or Regional Service, or Regional Haul or Pick-up & Delivery, NOT "Urban Delivery" To hold Goodyear responsible for the actions of others is not reasonable IMO. If your engine is supposed to run 5-30w oil and someone decides to use streight30w is that the fault of the oil company. Any of you who read my blog or attend my tire seminars at FMCA events have heard me warn about the incorrect application of products.
  15. Firestone F560 info HERE Last I heard was the 561 may be replacing the 560 in some sizes. Firestone and Bridgestone truck tires were being made at the same plant in TN but if this is important the DOT plant serial can confirm.
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