Big Truck Bias vs RV Radials

Tires are one of the four RV problem areas that I discuss while teaching my class " Four Biggest RV Maintenance Problems". I will be posting from time-to time about RV tires, but there is a large amount of material to discuss. This post will reveal a common problem of lack of specific knowledge about tires for RV's.

My class lecture begins by stating that you the RV user must gain some good factual knowledge about radial tires designed and compounded specifically for RV's. The fact that most tire dealers know very little about these specialty RV tires is illustrated by my search for and difficulties with a dealer that sold and mounted a new set of tires on my motorhome.

A Michelin dealer with all the equipment to properly mount and balance larger size truck tires. His business was incredibly active, but one that was about 99.9% providing tire service for big trucks. This dealer had some RV customers, mainly two RV dealers located less than a mile from his shop. He was aware that most RV tires are replaced in the 5-7 year timeframe and NOT because of tread wear. That was about the extent of his RV knowledge. I knew the specific Michelin radial tire I needed and he prepared a quote for me. It was a serious investment, so I deferred until I could research and learn for myself the cost/benefits involved.

Nine months later, my research complete and just past the 6 year birthday of my current tires, I placed my order for the RV radials for my rig. The old tires looked so good it almost seemed a crime to replace them, but the sun exposure does its damage much is not visible.

I had one after-market device, which I highly recommend, installed on the duals about three years prior. This is the Crossfire Equalizer Valves which I purchased online from a large Truck parts supplier. The equalizer valve is mounted to the center cover of the rear axle and has stainless air lines running to both tires on the dual. The valve equalizes the air pressure between the two tires and has the additional advantage of one valve stem to check and set tire pressure for the set of tires.

I have noticed this equalizer set up on many trucks on my travels back east, but very few in the western part of our country. This Michelin dealer had seen one on a truck he replaced the tires on. He told me they had problems after they mounted the new tires and they finally had to replace the stainless air lines to stop a small leak. Unfortunately, this was a bad omen for me as I had problems with a very slow loss of air on one set of duals during a long trip. After struggling with this this for most of the trip, I bought a plastic spray bottle and filled it with water and a couple of drops of Dawn dish soap. I squirted the water all over and checked and checked carefully for bubbles. Finally some very small bubbles appeared on the metal tube behind the tire valve stem.

The stainless steel flex hoses have metric size nuts to tighten on the valve stem. This nut was rounded off. Obviously, someone had used a English size wrench which rounded off the corners of the nut and the wrench pushed against the pipe portion and damaged it, causing the small leak.

Here is a handy tip to use if you are exposed small metric bolts and nuts in addition to English sizes up to about 3/4 inch. Always use the metric wrench when in doubt which will work on the English sizes to avoid damaging the nut and your knuckles.

During the dual tire air leak ordeal, I learned that tire dealers and road tire repair people do not know much about RV tires or equalizer valves, and I incorporated this into my class. About 2 weeks after my last class, during a RV park dinner, I was confronted by a sceptic, who stated loudly and emphaticly that RVers should just go to tire dealer and mount a tire that fits the 22.5 wheel. I didn't argue with him, but I soon found out I should have. About a week later, reading a weekly RV travel news e-mail, I found out Goodyear had been ordered by a judge to set a side $480,000 for potential lawsuits concerning truck tires mounted on a motorhome. The story detailed an accident that occurred to an Arizona couple that had new tires mounted on their motorhome. Probably at a Goodyear Tire Service store now called Iconic. The accident occurred in 2003 and was caused by a blow out of a front tire. The occupants were injured and the motorhome totaled. The tire dealer had sold and mounted a specialty truck tire manufactured for delivery trucks. It was a bias tire compounded for the lower speeds and loads of a local delivery truck. Goodyear had reached a settlement some years back with the couple, but their lawyer became aware that Goodyear had test information on the delivery tire that they withheld after specific requests during discovery. The judge was not amused. The tire did not test well at faster speeds and had excessive heat build up.

Again I repeat from my class - the typical tire dealer does not know the advantages of RV compounded radial tires or the disadvantages of using truck bias tires - therefore you must do your due diligence and educate yourself. Although, I suspect after this tire and resulting legal disaster, Goodyear will be educating their dealers.

A RV Radial tire ( available now from several manufactures for motorhomes and fifth wheels/ trailers ) has a tire engineer assigned to design, test and continually evaluate/improve; tire performance (handling ), tire longevity ( under RV conditions), rig fuel mileage, and proper tire pressures for various loads. The only advantage I can think of for a big truck bias tire is price Which could be 1/2 to 1/3 of a radial. The cost/benefit of a tire failure or blow out wipes out this price advantage. Check out other sources and evaluate for yourself. My recommendation is RV Radial in every instance. The question is - Is the initial cost savings worth the risk of a much costlier tire caused accident.