Tire Life

[TomC]

In my recent FMCA magazine, their was an article about motorhome designed tires.  At the end of the article was the statement that tires should be inspected once a year after 5 years and replaced at 10 years.  I went 12 years on my Dunlops, but also my bus is stored indoors.  Good Luck, TomC

[HB of CJ]

Thank you TomC.  Low mileage applications do take their $toll$ on the preventative maintenance schedule.  Wondering if we could see some Federal Law REQUIRING all sorts of things being done with our coach conversions to keep them licensed.  Kinda like private airplanes.  Obviously this would behoove us to take care of our own business, like tire inspections/replacements. 

[WEC4104]

This discussion leads me to wonder exactly what FMCA considers an "inspection".  If it is simply the owner doing a visual scan for cracks, imbedded items, irregular wear, and other defects (along with checking the pressure), I would hope folks are doing that more often than once a year, and not waiting 5 years to start.

Or, perhaps they have something else in mind.  Did they provide additional info about the inspection process (ie: removing the wheels from the vehicle or requiring the inspection be performed at a tire dealer or licensed inspection station)?

[Dreamscape]

This quoted from the issue TomC spoke of.


"Statistics indicate that the average life of an RV tire is five to seven years. After five years, the tires should be inspected annually by a tire specialist, and the maximum time before replacement in any case should be 10 years regardless of milage."

End quote.

Hope this helps.

Paul

[rv_safetyman]

As a part of my safety systems seminar, I talk about tire pressure monitors and then discuss general tire safety items.  I have done quite a bit of research and I can not find any specific replacement requirements by DOT or related agencies.  The only regulation I could find is that truck tires can not be retreaded if they are more than 7 years old.

There are lots of "recommendations" out there.  Perhaps 10 years is a good number.  However, a lot depends on how and where the tire is stored.  Ozone is one of the primary killers of rubber.  In the winter in Denver, the ozone can be very high.  Tires stored outside are more prone to environmental damage.   Covered tires and tires stored indoors last a bit longer. 

Some folks market "protectants".  From my many years in the rubber industry, I really don't think they do any good.

Most rubber compounds have anti-oxidants and other chemicals  in them to protect against degradation due to the "elements".  Each company has their own protection scheme and I would bet that there is a significant difference in "shelf life" of products from different manufactures.

About the best way to judge a tire from a safety standpoint (other than tread wear and looking for bulges/damage) is to look for significant small cracks in the sidewall.  As good as Michelins are, they tend to have sidewall checking earlier than other tires.  Some checking is not cause for immediate concern, but extensive cracking dictates immediate replacement.

We should probably adopt the philosophy of truckers.  ALWAYS have good tires on the steer axle.  Here I would stick with tires being less than 10 years old, preferably less than 7 years.  Move older tires to one of the rear axles or sell them to a trucker who will run them on a trailer.   


Tires cost a bundle, but a blown tire can cause thousands of dollars in damage to the bus (ask Jack Conrad), and can result in a serious wreck.  Not a place to cut corners.

Please understand that I am not an expert on tires.  These are just general recommendations and are not "handed down from on high"

Jim

[Lin]

One interesting thing you mentioned was about Michelin sidewalls.  I spoke to the truck mechanic that is working on my bus just yesterday about some Michelin takeoffs I was looking at.  He said that Michelins were great tires in general but, although he did not know why, they had a higher tendency for sidewall failure as they got older.  If I hear this a third time, then it must be true, right?

[Bob Belter]

Ahoy, TomC,


Some years ago I read that tire rubber compounds include a wax (like?) material which migrates outward.  The offering noted that the tire needed to be run periodically to achieve this effect and avoid cracking.

Accordingly, I got the impression that a long term 'parked' bus is NOT kind to the tires.

Any tire experts out there who can elaborate (and/or validate) this notion?

Enjoy  /s/  Bob

[HB of CJ]

I'm absolutely sure tire "protecterants" work perfectly.  Didn't that old guy from New Zealand just rub black boot polish onto/into his 20 year old hand buffed motorcycle tires to make them perfectly goof-er good  for 300 mph?  He he he.  Give me some Armoralll.

[H3Jim]

While we're doing heresay, I heard that the "protectants" jsut tend to draw more of the oils out, and so hasten the failure of the tire.  They make it look good for the short term, but the long term its worse than doing nothing.

Too bad my dad is not still around, he could answer this.  He worked for UniRoyal, (was US Rubber then) as a research chemist finding chemical additives to keep the UV from breaking down rubber tires so quickly.  He had a few patents, died in 1961, so that's ancient history now.  I'm down to just repeating hearsay...