tireman9

A 235/80R22.5 LR-G (110 psi) is rated 4675 single and 4300 dual Design rim width 6.75 Dual spacing 10.31 (< from Industry chart) a 275/70R22.5 LR-H (125 psi) is rated would be rated 6940 single 6395 dual Rim 7.5 Spacing 11.9 (< from GY chart) Your axle weights are very light! Are you sure the RV was fully loaded? I am a bit concerned with rim width and more concerned with dual spacing. The duals MUST have at lease an inch clearance at the bottom (near road surface). Yes 4 corner weights are hard to get but you can use axle scale reading and assume one end of the axle is supporting 52% of the load. Use that load to check the tables to learn the MINIMUM inflation needed. Add 10% to that Minimum with 15% inflation margin being better. Hope this helps

Well many people do not realize that almost every car sold today includes tire comparison tests as part of the development process so to do the evaluation and development properly each Motorhome model. ( Different chassis would definitely need a special tire evaluation but most other changes would not be considered significant unless there was some significant change in tire load distribution.)

Well I think that most of you missed the FLASHING RED LIGHT. A 295/80R22.5 is rated for 6,395 # at 110 psi while the 295/75R22.5 is rated for 5,675# at 110 psi. I have never been a fan of size comparison web sites as they are really intended for passenger and smaller LT tires and completely ignors load or dual spacing issues. I don't care about the speedometer error etc but I would be VERY concerned about giving up that much load capacity. It also creates a potential problem when selling the coach. How will this "Down-rating" lo load capacity be communicated or even understood by the new owner? We all know, or should know that a majority of RVs are overloading a tire or axle yet I almost never hear others jump in on such an obvious feature being overlooked.

I see nothing wrong with your tire selection but wonder when did you do or see a direct comparison of different brand tires on an RV? I have yet to see the results of any such comparison done under controlled test situation. Even I can still learn.

Nope, the hole in the wheel might be 0.453 or 0.625" but there are 2 different rubber gaskets involved. Unless someone installed a bolt in valve stem from a Farm Tractor application ALL tire valves for highway tires from the 10" tires on a 1965 Mini to a current 45' Class A would have the same 0.305-32 thread. Flow through caps also spec .305-32 thread. While I would not run TPM sensor on a flow thru cap as that is just another joint that could cause problems the TPM sensor should still fit on that cap. The next size up as used on tractor tires is 0.482-26 thread

Sorry to hear you had problems with tires in the '70's. Why did you let your wife drive a Caddy? Don't you remember reading about how unsafe the GM '59 Corvar was? We certainly should be concerned for all our friends driving on Ford products. You do remember the problems with the Pinto catching fire. Yes my examples are a bit extreme but IMO so is suggesting that a problem with a Passenger tire designed in 1965 has similar features to a truck tire designed in 2010 is similarly extreme. FYI I understand that Firestone & Dayton 22.5" tires are made in the same tire plant in TN as are many Bridgestone tires. You can confirm by checking the DOT serial. See you in Gillette

Not quite. I doubt that your motorcycle forum has discussions on how much oil you should run in your engine. 😁

I get a bit concerned when I read "acceptable alternative". Would be more comfortable if the ststement was more like..."The new tires have the same load capacity as the OE tires" or The new tires can carry xx% more load than the old tires. For too many people "acceptable alternative" may mean that the sidewall dimension numbers are close (but not identical) to the OE tires.

Here is link to Bridgestone selection. And if you want a ref Load/Inflation table chart for all except Michelin THIS should work.

OK. After you get the axle weights we would be interested to learn what your actual Reserve load is. Take care of yourself.

I'm not clear on what you are asking. I believe you know the actual load on your tires. Simply calculate 135% of that load and then find the tire inflation needed to support that 135% load. You many need to go to higher Load range or a larger tire or a combination to achieve that goal. I am not aware of any regulation that prohibits you from upgrading your tires or wheels to achiever the 135% figure. Alternately you could reduce your actual load such that your tires can support 135% of that reduced load. Note. I am not saying that achieving the goal of 135% in a MH is easy given they way they are currently designed i.e. limits of tire size.

Since I haven't seen the tires it's difficult to know what the issue really is. What did the Firestone dealer say when you had them inspect the tires? Can you provide some good pictures (well lit, reasonably close).

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The main difference is that cars have about 35% Reserve load capacity while most RVs are lucky if they have 10%. The placard inflation is reasonable till you confirm actual weights with scale weights. I suggest a minimum of 15% reserve load if possible. Once you know the minimum inflation for YOUR RV you should plan on adjusting as necessary when there is a change in Ambient of more than 20F which would have changed your inflation by 4%. Now if you run a 20% Reserve load as I do I can tolerate daily morning ambient changes on +/- 15F as I have a cushion built in. If I have the time and expect to run at the new Ambient I will probably adjust my morning "cold" inflation back to my goal. FYI I will be at Perry next week. two seminars on tires.

One major advantage of "top tier" tires is ease of service if any issues develop. My personal preference in TireTraker with their lifetime warranty. Link on my blog shows $289 for 4 sensor and extra sensors at $35. Unlike Amazon, Walmart or eBay they even know what an RV is. They are usually at FMCA Conventions too. I cover how I set and how to test TPMS on my blog. Note I get no commission from them. The ad is placed by the owner of the blog site RVTravel.com

Two things you must check when replacing tires. 1. The stated max load capacity molded on the tire sidewall. This should be stated in the tire company literature. 2. If you are not getting the identical 9not just close) size you MUST confirm the new tires have equal or greater load capacity than the old tires. Be careful with matching or higher Load Range. 3. If you change size be sure to confirm "Minimum Dual Spacing" You can learn more on dual spacing here

I have two blog posts on Tire Recalls about tire registration. If your tires are registered you would get a letter from NHTSA maybe even before the info is published. You might want to revied the psots and register your tires. You will need the FULL DOT serial to complete the registration. https://www.rvtiresafety.net/2015/10/do-you-have-defective-tires-how-would.html https://www.rvtiresafety.net/2017/11/did-your-rv-company-or-dealer-follow.html

The first concern should be Are the new tires rated for equal or greater load capacity? Once you have a "YES" then you can continue shopping. Note that there are a couple items in the Michelin line that are unique to Michelin. Either the specific size or the load capacity of the Michelin is a few pounds different than seen in other brands. This is because some Michelin tires were originally developed in Europe to metric dimensions and the conversion to Si (inches & pounds) requires some rounding so you need to be a smart shopper. Also for load. Have you learned the "4 corner" weights of your coach? You definitely need to ensure the tire you select can support at least that much load and a +argin of 15% would be a good idea if possible. FYI Firestone tires are made with the same or similar materials on the same equipment in the Bridgestone plant in Tenn. The sidewall will say "Made in USA"

Looked at the system install video. Not sure how this would be a good unit for RV owners. We already have internal TPM systems that do not require a wire harness in the market. Also not sure about transferring the sensor from one tire to another after the tire either wears out or ages out. But if you want to go this way and have considered my questions I would say go for it if you do not want the simpler, less expensive screw-on sensor units already used by many RV owners.

For the past few years I have been offering Seminars at the Int'l Conventions on the topic of Genealogy. Based on attendance and feedback this is an interest to many members of the FMCA family. While I was not able to present in 2020 I am planning on again delivering seminars at 2021 conventions starting in Perry. But not everyone can attend. With so many not getting out due to Covid I have been giving some Zoom meetings to local Genealogical societies on tracing your family tree. This might be something I can do for more members of the FMCA family. Researching your Family Tree can present opportunities to travel the country as you do your research. I would like to test the waters with a small group with a more "hands-on" approach and rather than just delivering a speech, I would like to work with folks just starting out and can schedule a few half hour Zoom meetings for groups less than 10 folks. If interested please message me so I can gauge the level of interest and see how to manage a few Zoom meetings. Possible Topics: "Where do i start?" "How to manage and organize your information" " Where can I find information on-line for free" 'Free Genealogical programs"

Comments on a number of posts. 1. Tire Industry standard as published by the "Tire & Rim Association" says to adjust tire pressure "When tires are at the prevailing atmospheric temperature and do not include any build-up due to vehicls operation". The 57 members of the association include Accuride, Cooper, Goodyear, Bridgestone, Continental, Michelin, Pirelli, Sumitomo, Titan, Toyo, Kenda, Maxxis, Dunlop, Hankook, Kumho, Nexen, Yokohama, Sailun and others. 2. I don't know why some feel the "prevailing atmospheric temperature" is some specific temperature i.e. 70 or 65F as I have been reading in some other RV forum threads. 3. Cars have placard inflation numbers that yield a reserve load capacity of 20% to 30% while most RVs have placard numbers that provide 0% to 10% and this excludes the 52% that we know have overloaded tires and/or axles based on the tens of thousands of weighings done by RVSEF. 4 I know no no one in the tire industry that is suggesting you adjust your tire pressure multiple times a day. The general recommendation is to adjust, in the morning before the tires are warmed by the Sun or by operation. 5 Cross country busses generally set their pressure at the tire sidewall pressure and never really completely cool down enough to end up in overload. 6 I do not know of any car company since 2000 that intenionally under-inflated their tires trying to get better ride. Most have designed their suspension (springs, shocks & bushings & seats) to provide the soft ride they want. They still provide significantly more load Reserve than seen on almost any RV. CAFE dictates that they shoot for better MPG because they have significan financial incentive to get better MPG.

Check out this post

I have a page in my tire blog that I try to keep up to date with links to various Load & Inflation tables. I think you will find that almost all tires follow the same numbers with the exception of a handful of Michelin 22.5 items. so if you can't find a chart from your tire brand you can use any of the others except Michelin. If anyone finds a broken link or error please let me know and I will do my best to fix the problem. RE how to do the calculations: Here is a worksheet from Bridgestone for doing the calculations if you find a scale that allows one side weighing. If you can only get the scale readings for your individual axles as you would from CAT scales or at other truck stops, I recommend not simply dividing the scale reading by 2 as very few RVs have their load evenly split 50/50 side to side. I suggest that at a minimum assume one end of an axle is carrying at least 51% of the axle load. If you have a big slide on one side or 2 slides on one side then I suggest you calculate 52 or even 53% of the axle load on one end. Residential refrigerators also can create an unbalance. All of this shows the importance of at least one time getting a scale reading for each tire position (a pair of rear duals counts as one position). Using those numbers calculate your side to side split percentage and use that from then on unless or until you get another "4 corner" scale reading at an FMCA Convention or similar. We have found that some RVs had as much as 1,000# more load on one end of an axle so the unbalance can be consequential. Many times local building supply or sand & gravel or farm feed supply locations have small scales that can give the one side reading so you can use the Bridgestone sheet above. When consulting the tables ALWAYS use the load on the heavy end of an axle to look up the MINIMUM inflation. ALWAYS go up in inflation to the next 5 psi box. Don't try to split the difference. I also suggest you add 10% to the table number so you can avoid "chasing your tail" with daily temperature induced pressure changes. Finally ALWAYS set all tires on an axle to the same inflation level and use a TPMS. Here is my blog post on how I program my TPMS.

If something gets in the core the only "fix" is to replace the core itself. There is no opening between the stem and core like n a water faucet so drying to clear the dust by removing the core will not work. Re over tightening the core. Spec is 2 to 5 in-Oz. I just tested a neat tool from SLIME. A Torque limiting tool. $5 at Autozone. I tested it and it "clicks" and releases at 3.5 in-oz. Will be posting on my blog soon as a tool I "Endorse".

I like your approach. Until you get actual individual tire position weights you should be good.