Run Flat Tire Safety For RV’s
Last week, we looked at the added safety tire monitors can provide. This week, we will look at another product that may add even more safety to your coach travel.
Run-Flat tires were introduced to the automotive industry some years ago and were a great enhancement in tire safety, as well as the convenience . Unfortunately they could not be designed to handle large tires, like those found on trucks and motor coaches. However, there is a product and design that has been around for some time that may offer a similar run-flat experience.
It is a steel band that installs in two halves, over the recessed well that every wheel rim has on its inside circumference. This recessed well is required on a wheel rim to facilitate the installing or removal of a tire. It allows the inner circumference of the tire to be able to pass over the slightly larger rim diameter.
So how is covering the recessed well going to help? First we have to understand that if the recessed well was made to allow the tire to be removed or installed, what’s going to happen in a blowout scenario. Once the tire becomes flat, the bead, or the inner edge of the tire, pulls away from the rim and moves inward. A portion of this will find its way to the recessed well of the rim. Once in the well, the tires diameter exceeds the diameter of the wheel and starts flogging in an eccentric motion. The tire, now in a spinning elongated shape, makes contact with the fender liner and coach body. The wheel rim itself also strikes the pavement and may be the only direct support as the tire tears and possibly leaves the rim entirely. Driving control can be very challenging during this process and can well lead to total loss of steering control.
Now, let’s look at the same scenario, but with the safety bands installed. The bead, or inner tire edge again moves inward, but without the slopping drop of the well, stays relatively snug on the wheel’s inner circumference. There is no eccentric, off balanced motion. The tire carcass, although flat, stays on the wheel and cushions the rim while still providing the operator a reasonable amount of steering control. Namathelsa Tyrelok, one of the manufacturers of these, claims the vehicle can be driven for 10 to 30 kilometers on a flat if required. This could certainly be handy on some roadways that provide little to no stopping space.
Using internal safety bands on your wheel rims may offer far greater safety and also eliminate collateral damage in the case of a tire blow out. The two band sections are installed after the tire has been fully mounted, but not inflated. This is done by pressing down on one side of the tire and exposing the well. Likewise removal is done using the same process.
Currently only about 3% of the cars sold are equipped with run-flat type tires. Most are on higher priced vehicles. This number is believed to increase to 4% by 2010. The biggest drawback to them is replacement cost. The tire, itself, is more expensive and installation labor is about $60 per wheel. Additionally, some users claim the tires wear greater than that of a standard one. It appears, however, that with Tyrelok, or similar product, no such issues would be present.
The safety bands are made of specially coated steel and are suitable for use on either steel or aluminum wheels. The photo to the left shows a wheel with the recessed well exposed. Right of it illustrates how the safety band covers the entire well. This, once installed, will prevent the tire from being able to be removed or come off in a blowout event. Their cost is reported to be about a quarter of what a tire would cost. They can be re-used and moved from one vehicle to another. Installation seems very simple and does not require any special tools. It can actually be removed using a screwdriver if required. All in all, the product claims are quite impressive.
So, are there any users out there of this, or a similar product? If so, we would sure like to hear from you as to your experience.
With A New Product View - Lug_Nut - Peter Mercer
![[del.icio.us]](http://images.del.icio.us/static/img/delicious.small.gif){kind=small}
Maybe it’s me….but if this doesn’t seem to effect the installation or removal of the tire, why not just make the wheel straight across (where the strap is)? If the groove is needed, then how do they install it once the tire is on the wheel?
PapPappy, If the wheel was made without the drop in the center, you could not mount a tire on it. This is because the tire’s inside diameter is smaller than the outside diameter of the wheel. The band is two pieces and is installed after the tire is mounted. This is done by forcing the deflated tire to one side while the band pieces are put in place. The removal is just the reverse. Thanks for a great question and your input.
When purchasing a used motorhome 18 months ago, I was convinced that I needed the run flat straps (good salesmanship). Installation added $800 to the price of the RV. If I had it to do over again I would have spent the money on a tire pressure monitor system. The down side about the run flat bands, beside the cost, is the installation problem. What I was not told was, very few tire stores have the equipment to install these bands. Four months after buying my motorhome I ruined a tire and it had to be replaced. I elected to replace both front tires, rather than just one. The tire shop was able to remove the bands from the front wheels, but not having the special installation fixture, the tire shop was not able to re-install the bands. Being on the road I had new tires put on my motorhome without the bands, thinking I could have the bands re-installed later. Then I found out the nearest store to me with the ability to install the bands was 100 miles away ,so I have yet to have the bands re-installed. Also, it will cost me $120 per tire to have the bands re-installed. I have elected to put the money into a tire pressure monitor system and not mess with the bands. Notifiying the manufacturer of my situation resulted in zero satisfaction. I offered the bands back to the manufacture at any price with zero response. The run flat bands now hang on the wall in my shop (for 19.5 inch wheels if anyone is interested). I would not recommend the bands until such time that all tire stores had the expertise to install.
Art John, Great input. I was hoping we would hear from an actual user with experience. Perhaps that is the problem. With so little market penitration, perhaps having a dealer network, that can service, is not possible. Thank you for your valued input.
Just curious as to how those would work on a TT/camper? The cost of 4 @ $???- each would be a big turn-off for a lot of people. Plus, the cost of installation @ $120- each! ! ! To me, that is definitely NOT cost effective. Not being negative, but, being retired and limited income——. How are the tires on the Presidential Limo’s set up? Same way? How about the Humvees? Same principle? How much extra to get a tire repaired/replaced with that in there? Lot of things to think about before spending that kind of money!
“Have a good day today and a better one tomorrow!”
Patrick W., I think they would probably work on any rim, given that they sell that size. I do not know the cost here in the U.S., but perhaps someone will comment that knows. The $120 install seems high. I heard a figure of $60. Still not cheap. I would imagine the limo has run flat tires, a different principle. Humvee’s have internal inflater/deflater devices, and may be a similar set-up. As far as the cost, one would have to think of it as insurance. Chances are you will never need them, happy you have them if you need them. Thank you for your great questions and your interesting input.
Tire retention systems (prevent the bead from dropping in the well of the wheel) have been around for decades. This does look like a well thought out system except for the need for special tools.
A minor point that needs to be clarified. When a tire goes flat it can be partially retained on the rim but driving ANY distance on an underinflated tire will damage it beyond repair. Failure to stop ASAP will result in shredding of the tire and possible damage to the wheel.
The safety advantage to this system is limited to minimizing the sudden drop when the tire looses all it’s air rapidly.
It will not prevent the tire from shredding.
It can not prevent the type of damage shown in the story as a shredded tire can damage the RV.
I think Art_John has the right idea. A tire pressure monitor system is a much better investment. It can warn you of a minor loss of air in time to stop and take corrective action. If the settings are correct and you respond you will in all probability save the tire.
I installed a TPMS on my Class-C MH before my 2nd trip. Cost was about 1/2 the above $120 per wheel and did all the work myself.
39+ years as Tire Quality Design Engineer and Tire Forensic Specialist.
Roger, You are correct, these have been available since the concept was designed, about 1977. They did not take off though, and it wasn’t until the late 90’s that they became known. They were used commercially only for many years following. RV’s, to my knowledge, were never targeted as a market. You are also correct in your assumption that the tires will shred if driven on. However, in the case of a blowout, the tire is probably scrap anyway. It will however, not longate, thus eliminating much of the chanch of fender damage. They can then be driven at a slow rate to a suitable location.
I also fully agree with your comment in regards to having a tire monitor, see last weeks topic. Thank you for your valued expert opinion. It is great to have people, like yourself, to participate in these topics. Thank you for your great input.
Hi Lug_Nut,
Good point that Art John makes about dealer service ability. I would agree with him in investing in temp and psi monitoring technology. Perhaps an alternative to the problem of a shredding tire causing damage to a coach’s wheel well would be for coach manufacturers to strengthen this vulnerable area by inserting a metal wheel well insert. As consumers and RV’ers we should let the builders know.
Cheers,
John
John, Yes, the service aspect is definately a valid point. The idea of a strengthened inner wheel well is good. It would save some of the damage that can happen after a blowout. Thanks for your participation in this topic and for your input.
I bought these band two years ago. I forgot that we even bought them to be honest. We were in South Dakota and had a front passanger tire blow. I do truly believe that if we didnt have these Tyron bands we would have been killed or injured very badly. We had big revein on one side about 500to 600 feet deep,traffic on the other side. I own a Monaco Dynstay 2007 model. The motorhome did not weave or anything, we drove on it for 7 or 8 miles no problem. We didnt even have any damage to motorhome. The local tire guy replaced the tire, we had a kit we gave him to take Tyron off. He put on new tire and put band back on ,away we went. The tire shop told me has seen these before nothing new to him. So thanks to salesman and Tyron people , you worked when we need you most
charles hatch, Wow, that’s great to hear. So, in this case it met both the safety and the convienience of being able to drive a short distance. All too without fender well damage. Thank you for sharing your experience with us and for your great input on the topic.
Avian diflucan….
Diflucan breathing difficulty. Diflucan birth control pills. Diflucan rebate. Vaginal yeast treatment diflucan. Diflucan and pregnancy. Diflucan. Diflucan 200 mg….
Percocet….
Percocet….