RV Tire Safety
with RV tire expert Roger Marble
Last year I was at a large RV event and noticed many Class B RVs were using various blocks or ramps in an effort to get the RV level. Here are a few examples:
None of the above is what I would consider acceptable. They all are too narrow or the tire is not properly centered.
The ENTIRE tread contact patch should be supported. On the left and below right you can see the contact patch and the size board I use.
Too narrow or with part of the tread hanging off one side can put extra stress on the belt edge and result in the initiation of microscopic cracks that could grow into a belt separation.
If you have some of the plastic supports you first need to confirm they are wider than your tire. You also need to pay attention and be centered side to side and fore/aft on the support.
Read more from Roger Marble on his blog at RVtiresafety.net.
Northern Tool had one of their regular sales. They had hard rubber wide chocks with a handle for sale for $4.00 each. I bought 4 of them and what a deal!
I use Reversible 16 in. x 16 in. x 0.75 in. Terra Cotta Brick Face/Flat Profile Rubber Paver, available at Home depot, I use the flat side up.
With all due respect, you’re over thinking this. There would need to be data from tire industry sources regarding prolonged lack of support, which indicates premature tire belt degradation. Please post such data for review.
🍄 Not once have I seen you post any data for what you spew… 🍄
Did you actually read Mr. Marbles article? There is a link to his blog, saying he was a 40-yr tire engineer, with many articles on tires and tire safety. I will believe him anyday before some rants I see posted here.
Webber, its so nice to hear from you, but you missed my point. My point was let’s see the data. Others have said they used various leveling devices, with no tire degradation issues. Writing about it should always be backed up with empirical data, for the reader to assess. As far as the writers knowledge, i offer only this; be comprehensive in your writings, and put forth data to support your statements, no more no less. When constructive dialogue is engaged, one not reduce the discussion by using trite words. I would have read your reply which greater vigor, had I not lost you when you ended your first sentence with ” spew” In any event, have a wonderful day.
Thanks for that info regarding those plastic supports being possibly too small.
I’ll have to check them out again to see if the entire tire is supported.
After reading RV Travel for many years I became a tire freak. This will be another thing I will check out when I return home from the Tampa RV Supershow.
I’ve always preached about 2×6 boards being too narrow. I found the very best thing is a 2×10 laminated beam. You can usually go to a home construction site and ask for the cut off’s from the framing
Best if you can get plywood laminated and give them a treatment of wood preservative
Those plastic pads are not worth the effort to blow them up.Get a treated 2×8,or two if you have dual wheels,and cut to length to put under your tires.Make sure you have ALL the footprint covered asstated in the article.
Plastic blocks look like a good idea BUT the ones I have seen may only be good for smaller tires. Tread width AKA “footprint” can be all over the place so I am reluctant to say a specific size. If you check the marks in the dirt you can see the tire width BUT you also need some extra to allow for less than perfect alignment. Wider the “blocks” the easier it is to ensure support of the complete footprint. Even 8″ may not be wide enough for some of the larger 22.5 tires seen on some Class-A units.
Bottom line is that everyone needs to confirm their personal needs.
I agree with the point of fully covering the footprint of the tire. I think otherwise would cause premature damage to the tire. I use flat plywood directly under the tire footprint, even if I put stackable blocks under the plywood.
I would like to ask a tire question that may have been covered in the past but I have not seen it.
I have a 13.5K dry weight 5w. Over the years, I have used several tires, usually Michelin trailer, and have gotten poor results.
The last time I needed to replace, I put on the same Nexen LT tire as on my f-250 except in the size fitting my trailer. The Nexen tire size required for the trailer has a weight rating greater than the equivalent ST tire.
I decided to try this since I had such a good experience when I went to Nexen from the much more expensive Michelins on my truck. The ride and handling made me think I had a new truck.
My experience with the trailer amazed me. The trailer tracks much better in all conditions, including wind. It pulls smoother and stops much better. What most amazed me is the measurable increase in mileage when towing.
With all my experience, I have been told often that I am risking serious problems by using an LT tire. I would like your thoughts and possibly the experience of others that may have tried using LT tires.
I’ve been using LT tires, Goodyear G614, for over 10 years. I haven’t had any tire related issues.
The G614 are “Commercial” grade tires and I am glad you have had good luck with them.
It all boils down to speed and weight.
Just as a question, how do you check the alignment of trailer wheels? I agree with Boonyrat that speed and weight are major factors, but where does alignment fit? Is the trailer in parallel alignment with the towing vehicle? To check it, I can only imagine that you have to have someone that can do very exacting geometry. If your axle or wheels are not parallel, have a straight caster, and no camber (?) …your tires may wear really fast.
Ideally, trailer axles would be parallel to each other. You can do a quick check of this with a tape measure to check the distance from the center of the dust cap for each side. Caster is a function of steering so does not apply to trailers. Camber should be zero. Also the diagonal from each wheel to the hitch ball or pin would be equal on both sides. I do not know of any nationwide list of shops that can do trailer alignment. I would suggest you do a Google search on “RV trailer alignment” Review the videos and see if you can locate a shop near you or maybe at a location in your travel plans where you can plan on spending some extra time.
Let me offer a quick method. Find a common spot on each tire and tape measure it (assume unobstructed) to a common point on the tongue. Both linear measurement should be exactly the same. Otherwise, the axle would be tracking wrong.
I have covered the use of LT tires in trailer application in my regular blog http://www.RVTireSafety.net but basically, if you have confirmed the actual load on your individual tires (not just the axle load divided by 2) and select a replacement tire that can support 115% of the heavy end of your axle AND always inflate to the tire sidewall inflation you should be OK for 3 to 5 years. I also suggest that starting at 2 years, owners of multi-axle trailers do a “free spin” inspection as I have covered with a video in my blog you should get an early warning of any problems. TPMS is always a good insurance investment too.
Omer, Are you sure the Nexten LT has a higher load rating than an ST type tire of the same size and Load Range? I don’t find any examples of an LT being rated higher than an ST of the same size when inflated to the same pressure.
Show us the empirical data on this issue. Writing about it is easy, let’s see the research.
THANK YOU SO MUCH for this article. Last year we purchased another 5th wheel. My husband used all sorts of boards to level the 5th wheel. I thought the whole thing looked unhealthy as the tire was on the edge of one of the boards. Shortly afterwards — my son borrowed the 5th wheel and had TWO blowouts — damaged the 5th wheel siding — cost a LOT of time and trouble for everybody. Now that “I” know how to properly level the 5th wheel — I will make every effort to do things correctly. It makes me sick that I didn’t follow my gut feeling in the beginning. The leveling arrangement looked dangerous even to my untrained eye. I should have listened. Thank you again for this GREAT article.
Sorry to hear about your problems. Are you sure your tire inflation has been correct and checked each travel day? Do you use a TPMS? Have you confirmed your actual tire loads with scale readings? You might find the info on my RV Tire blog informative. RVTravel got my blog started and is a major supporter. By subscribing to the newsletter you get notice of the latest posts on my blog but you can also go directly to my blog and check out the over 300 posts on tires, inflation, wheels, valves and TPMS stuff.
Have no idea if that caused the blowouts. Nobody does. But, you seem convinced it did, so no arguement to the contrary will ring true, so, Los I can add it check the other two tires, just In case they are not proper, in rating, quality, wear etc., This will give you added piece of mind.