Leveling Block and Ramp Width February 16, 2005, 12:01:31 am Yahoo Message Number: 50826Some time ago in this group, Mike Richmond mentioned that the manufacturers of tires for RVs recommended only using blocks or levelers at least as wide as the tires to prevent stress and possible damage to the tires. I finally got around to checking the Goodyear and Michelin sites. Goodyear didn't have a whole lot: http://www.goodyear.com/rv/tirecare/generalcare.html"USE OF BLOCKS The entire footprint of the tire should be supported by blocks, with no tread hanging over the sides. When the tread is unsupported, excessive stress is placed on the tire components."Michelin's web site offered more on page 12 of the pdf file: http://www.michelintruck.com/michelintruck/pdf/RVTIREGUIDE1.pdf"THE USE OF BLOCKS TO LEVEL MOTOR HOMES/RV'S EQUIPPED WITH RADIAL TIRES Extreme caution must be taken to ensure that the tires are fully supported when using blocks to level motorhomes and/or RV's. The load on the tire should be evenly distributed on the block and in the case of duals, evenly distributed on blocks for both tires. If not properly done, the steel cables in the sidewall of the tires may be damaged and could lead to premature fatigue of the sidewall. The correct and incorrect methods are shown here. [illustration] Please note that blocks should be wider than the tread and longer than the tire's footprint. This provides maximum support to the tires and assures that the load is evenly distributed throughout the tire's footprint area."Sharon N.
Re: Leveling Block and Ramp Width Reply #1 – February 16, 2005, 09:23:12 am Yahoo Message Number: 50833wrote: "http://www.goodyear.com/rv/tirecare/generalcare.html "USE OF BLOCKS The entire footprint of the tire should be supported by blocks, with no tread hanging over the sides. When the tread is unsupported, excessive stress is placed on the tire components." http://www.michelintruck.com/michelintruck/pdf/RVTIREGUIDE1.pdf"THE USE OF BLOCKS TO LEVEL MOTOR HOMES/RV'S EQUIPPED WITH RADIAL TIRES Extreme caution must be taken to ensure that the tires are fully supported when using blocks to level motorhomes and/or RV's. The load on the tire should be evenly distributed on the block and in the case of duals, evenly distributed on blocks for both tires. If not properly done, the steel cables in the sidewall of the tires may be damaged and could lead to premature fatigue of the sidewall."This good advice does bear repeating (see post #50676); RV tires are subject to enough stress while running, so when sitting blocked, they deserve a wide, supportive "bed". IMO, an 8" leveler is not wide enough; the tire's *tread* width (on a 225/75R/16) is about 7" (the *tire* width is about 8.86"). In some rough conditions, it can be difficult to get the tire(s) squarely on the block(s). Wider blocks allow more leeway to support the tire's footprint all around.Joan
Re: Leveling Block and Ramp Width Reply #2 – February 16, 2005, 09:50:17 am Yahoo Message Number: 50839Quote "The entire footprint of the tire should be supported by blocks..."Quote"The load on the tire should be evenly distributed on the block and... could lead to premature fatigue of the sidewall.Quote"...This provides maximum support to the tires and assures that the load is evenly distributed throughout the tire's footprint area."Quote Sharon N. Sharon & GroupAnd, by that token, one would presume this sage advice would also extend to the use or the open grid type such as the Lynx levelers. Or did I miss something?Steve S. Lazy Bones
Re: Leveling Block and Ramp Width Reply #3 – February 16, 2005, 11:18:47 am Yahoo Message Number: 50843Quote "The entire footprint of the tire should be supported by blocks...""The load on the tire should be evenly distributed on the block and... could lead to premature fatigue of the sidewall."...This provides maximum support to the tires and assures that the load is evenly distributed throughout the tire's footprint area."And, by that token, one would presume this sage advice would also extend to the use or the open grid type such as the Lynx levelers. Or did I miss something? I generally level using some 2x10 boards that I cut, I occasionally resort to using stacking blocks. I have one bag each of the Lynx and yellow "Lego" blocks. The Lynx (orange) block are much studier.I've been following the threads about the blocks and giving it some thought. The tires have been designed so that the tread contact patch can properly distribute the force caused by the weight carried by that tire, from the road surface up through the sidewalls to the whole of the tire. It has to do this while flexing as the tire rotates and takes sideways forces. Also remember that the tread pattern itself is a series of blocks and gaps. I believe that overall that this is a very tough system. I think that the important point is that most of the time the load needs to be evenly distributed over the contact patch. As long as the entire contact patch is supported, I believe the tread part of the tire can properly distribute the forces from the contact points on either the Lynx or other blocks. *Disclaimer* - I'm not a tire design engineer.Just my $0.02, Art
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Topic: Leveling Block and Ramp Width (Read 10 times)
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