RV Tire Safety: “I never hit a pothole” – so why did the tire fail?

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with RV tire expert Roger Marble

The title for this post is a direct quote made by many people who have suffered some tire failure. If you think about this claim for a moment and then think about the road conditions we all see in our day-to-day driving experience one has to wonder just where these people are driving.


In our life as drivers, I am sure that all of us have hit some objects other than a simple 1″ deep pot hole. Some objects could include bricks, lumber, railroad tracks or curbs, and puncturing or cutting objects such as nails or screws.

Here are some examples of tire damage I discovered in my work. The first three were each submitted with a written claim that the tire was “defective,” so I can only assume the driver made little or no effort to inspect the tire or wheel for evidence of what might really have happened.

(left) Impact mark on tire and wheel. (right) Rim impact damage.

The last tire, with the wooden stake through the tread, was submitted with a claim that the tire was defective because it was “making noise.” IMO the noise would have been from the wood hitting the pavement at speed.

I have no expectation of changing the minds of those who want to make a claim of never hitting a curb or pothole or another object. I do want to relate the findings I recently discovered in a technical paper on tire forensics and impact damage.

In the paper, the reference studies involved a process of obtaining a couple dozen both new and used tires P type, LT type and sizes appropriate on some Class-A RVs. The rim diameters ranged from 14″ to 19.5″. Tires came from 8 different tire companies. Each tire was inspected and no externally visible signs of damage were found. Each tire was run on the appropriate DOT laboratory tests to confirm the tire was in good condition. Each tire was then mounted and hit with a heavy pendulum to simulate hitting some object or pothole on the road using a machine like this from Standard Testing Labs.

The tires were again visually inspected and any evidence recorded. Finally, every tire was run on a drum durability test under a load until failure occurred.

RESULTS:
• Failure Rate 100%
• Miles to failure for new tires 1,826 mi. to 41,400 (avg. 11,586)
• Miles to failure for used tires 5 mi. to 7,458 (avg. 2,092)

Can anyone here list every object they knowingly or unknowingly hit over the past 2,000 miles?

I know that I have posted a number of times that tires do not always fail at the instant of impact or damage. Clearly, the above studies confirm these observations.

Some reference material for those interested:

Price, V & Follen, G (2019). Road Hazard Impacts: Their Influence on Radial Passenger Tires and the Forensic Signs They Leave Behind.

Bolden, G. C., Smith, J. M., & Flood, T. R. (2001). Impact Simulations in the Lab. Tire Technology International.

Bolden, G. C., Smith, J. M., & Flood, T. R. (2005). Impact simulations – what happens when a tire/wheel impacts a road hazard. Tire Technology International, 44.

Bolden, G. C., Smith, J. M., & Flood, T. R. (2006). Structural Impact Damage Under Varying Laboratory Conditions. Tire Technology International, 10.

Gent, A. N., & Walter, J. D. (2005). The Pneumatic Tire. Washington: National Highway Traffic Safety Administration, U.S. Department of Transportation.

Giapponi, T. R. (2008). Tire Forensic Investigation: Analyzing Tire Failure. Warrendale: SAE International.

McClain, C. P., & DiTallo, M. A. (2001). Tire Examination After Motor Vehicle Collisions. In K. Baker, Traffic Accident Collision Investigation (9 ed.). Evanston, Il: Northwestern University Center for Public Safety.

Tire Industry Association (2005). Passenger & Light Truck Tire Conditions Manual.

Read more from Roger Marble on his blog at RVtiresafety.net or on RVtravel.com.

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TravelingMan

How many crappy bridges or potholes have you hit?

Ever driven in Oklahoma or Michigan?

In addition to tire road hazard insurance, one might also consider increases in medical and dental road hazard insurance as well.

Dennis

Hit a tire-gator on the 15 entering Las Vegas two summers ago, with my right front tire. The tires were brand new-just mounted before our vacation.

After impact everything seemed okay. The RV still tracked straight, and there were no vibrations. We pulled over and saw no visible damage to the tire or coach. We continued for another 10 days and finished our southwest vacation.
Approximately four to six months later I began to barely hear an audible rhythmic thumping from the right front at 60-65 mph. It was so slight that my first thought was I’m imagining things. A few hundred miles later the rhythmic sound (similar to semi trailer tires I’m heard while going down to interstate) became more pronounced. Still, there was no visible damage, nor could the tire tech find any internal damage.
We decided it was best to retired the right front tire and replace it for a new one. The rhythmic noise was gone. We can only surmise a belt was damaged and that it was progressively getting worse.
That decision most likely saved us from a catastrophic tire failure, RV body damage and a potential accident.

Dennis Thayer

Roger, I always appreciate your articles here and comments on Airforums. I’ve had 2 tire failures and both were caused by sidewall damage when I cut a corner too hard and hit the sidewalls. Thanks for all your advice and I look forward to any new material you present.

Mark

I am certainly not a tire expert but I would think even some of the seams between the bridges and roads could potentially cause damage. Anyone who has wandered on the interstates at 65 or so has inevitabley been jarred out of their seat from time to time. This can’t be any different from hitting a pothole at 65.