BAC Forum
General Boards => Technical Support => Topic started by: Steve Adams on November 12, 2010, 08:29:53 AM
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When we purchased our 2001 Beaver Contessa 40' the previous owner had installed Toyo 265/75R22.5 Load Range G tires. The maximum carrying capacity listed for that tire is 5205 pounds at max pressure. We had the coach weighed and the front end weighs 10400 without a driver or passenger. The data plate for the unit says the front axle is rated for 10,400, how convenient! Sitting still we are at the capacity of the tires and axle and we are not going to change the axle. We have the same issue with the left rear where the weight is 10,800. If I'm reading the chart correctly the dual capacity for this tire is 4805 X 2 = 9610, or 1200 pounds below the actual weight. The right side weight is 8,800 which is well within the range of the existing tires.
I cannot seem to find a tire that will give us the weight carrying capacity we need in the 265/75R22.5 size. The closest I have found is 275/80R22.5 or a 275/70R22.5
When I compare the tire sizes this is what I'm seeing;
Mfg TOYO Goodyear/Michelin
Size 265/75R22.5 275/70R22.5 275/80R22.5
Diameter 38.5 38.0 39.7
Width 10.9 10.9 11.1
RPM 540 545 524
Single 5205 6945 6175
Dual 4805 6395 5675
Oddly enough when I went to the Les Schwab site the 265/75R22.5 was greyed out, meaning no longer available.
Besides the obvious improvement in capacity with either of the new tires, is there enough of a difference in the other characteristics to make a difference in how they fit? Both say they will fit the rims I have which is one good thing.
While I'm at it I'll take recommendations on tire pressure monitoring systems. Brands, model #'s, etc. Internal sensors or external (valve stem sensors), any issues with sending units, the need for repeaters, etc.
Thanks in advance for your input.
Thanks, Steve
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We found that the Toyo tires wear irregularly, perhaps from the overloading. Our steer axle now has Michelin XZA2 Energy 295/80R/22.5 LR H which gives us 7830/6940 up from the 11R22.5 LR H with 6610/6005 that came from the factory. We do have some wheel well drag on a very tight turn. Not sure what the difference is, if any, in the wheel well between yours and ours.
I think that Good Year has a chart on their web site that show the diameter of the different tire sizes. I remember using it to try to keep the tires as close to original as possible. The new ones are quite a bit wider though.
The axle rating is based on the weakest item on the assembly including the tires. It is possible, but not absolute, that your tires were that weak item when the max load was established. The tires are certainly the most likely item to fail if overloaded.
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We have had rivering wear on the front steer tires with Goodyear G159 and G670 275/70 R 22.5 H on our coach and just changed to Michelin XZA 2 Energy 275/70 R 22.5 J tires. We have not traveled far enough to see a wear pattern yet.
Motorhome originally had 255/70 R 22.5 H tires and after two front tire failures we went to the larger tire. We were able to reposition the front axle to get proper clerance when turning. Beaver/Magnum actually had a procedure for the axle reposition to accomodate the larger tire but if you mentioned "overloaded axle" they would clam up and walk away.
We have had three front tire failures and Toyo stood behind the first two and a sidewall failure on the largers tire was a Goodyear G670 and they stood behind their tire also.
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Regarding TIRE PRESSURE MONITORS.....(While I'm at it I'll take recommendations on tire pressure monitoring systems. Brands, model #'s, etc. Internal sensors or external (valve stem sensors), any issues with sending units, the need for repeaters, etc. )
For a number of years I used Pressure Pro and was so DIS-SATISFIED I finally checked out and purchased a new system. The Pressure Pro would never give me accurate readings, many times it could not even sense pressure on the motorhome, let alone the toad even with a repeater which ran the battery down to dead on the toad! It was confusing to setup, you have to remove the sensors to check pressure with a gauge, the alarm was constantly going off in-accurately, one can NOT at a glance see what the pressure ready is, and the tire temp is not available.
I now have the Tire-Safe Guard by GENCO which is absolutely great! It constantly lets you see the pressure and temp of each tire, and warns if outside the parameter settings, can be calibrated to closely match the reading of a good digital gauge, you don't have to remove the sensor to take a reading by a gauge particularily on the motorhome and if you have metal stems on the toad you can do the same.
I had metal stems put on PT Cruiser sometime prior with new tires so I ordered the same sensors for all.
Check it out....../www.tiresafeguardusa.com/compare.html
Leah http://www.tiresafeguardusa.com/compare.html Clickible link
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Just as a precaution, check the capacity stamped on the rims also, as they can fail if overloaded; if factory original they are probably fine as long as the coach is loaded within specs. Our coach is off side to side in the back also, by 1500lbs; yours by a ton. I haven't quite determined exactly why there is such a significant difference, but no one, including Bend and the RVSEF seems concerned, as long as both sides' tires are inflated to allow for the heaviest side.
One main concern is tire width beyond what the dual rim spacings were designed for; you don't want radials scrubbing each other back there. Don't know why your chart width shows the same (10.9) for the 265 and 275, because they are by definition 10mm (~3/8") different. If that's correct, the 275's should mount 1 cm. closer together than your 265's. The 275/80R's have a sidewall more than 3/4" wider, which affects coach height; conversely, the 275/70R's calculate to sit about 1/4" lower than the 265's, making them your most likely candidate, though their load rating may be higher (J?) than needed (H?).
Other BAC members are more expert on tires than I, so hopefully they will add some input for you.
-Joel
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Tire manufactures have approved rim widths for mounting in their data and it is easily accessable. The Big thing is that some wheels are rated to 120 psi cold and the tires are rated higher. Used the lowest psi cold rated componet be it tire or wheel.
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Steve,
It does not sound like you are comparing tires with the same load rating. In the same load rating,, a 275/80 will carry more load than a 275/70. Regardless if your tires are that badly overloaded, you need to upgrade them.
First you need to determine how much room you have to go to a larger size tire. You have to be careful about the tires rubbing when turning because there is probably an air bag located directly behind the front wheel housing. If the tire rubs too much on the wheel housing when turning, the air bag will be damaged. After you determine how large of a tire you can use, you can then compare the tires that are available in that size to best suit your needs. You will probably find that the 275/70/22.5 in a load range H is the tire that will best fit your needs.
Gerald
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I have lots of questions. We just purchased a 1989 Beaver Marquis with 10x22.5 tires. The two front tires are about 18 months old by mfg date. The two outside duals are 9 and 10 yrs old. We will not be traveling over 200-250 miles...no real long cross country trips. Should I consider the tire monitor system mentioned earlier on this thread to monitor the tires. Or should I consider getting new tires? Also, how do I find the load capacity of the rims? Or the PSI ratings on the rims.
Thank you to each one who responds with their experience and knowledge.
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Gary,
First the load capacity and maximum air pressure of the tires is molded in the sidewall of all of your tires and the load capacity and maximum air pressure of the wheels is stamped in the wheel. The stamp on the wheel will be on the inside so you can find it on your rear outside dual wheels.
The load capacity will not do you a lot of good unless you know what the coach weighs. Do not believe the factory weight labels. Weigh the coach packed the way that you travel. an inflate the tires according to the actual weight of the coach using the tire manufacture's weight/inflation tables. If you do not know what the coach weighs, I would run the tires at their maximum inflation.
As for as your 9 or 10 year old tires on the rear of the coach, I would replace them now. The life expectancy of your tires is 6 years. Some people stretch that to 7 years, but no one should be driving on 10 year old tires.
As for as purchasing a tire pressure monitoring system, I use one for convenience, but a good tire pressure gauge will do the same thing with the exception of reading the pressure as you drive so that you are notified if a tire starts loosing pressure as you are driving.
Gerald
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I have to agree with Gerald, Gary. You need to get new rear tires asap.
Tire pressure monitors are nice to have, but I've not splurged for a set; if you're going to do it, you might as well monitor all 10 tires - coach and toad (12 with a tag axle). That can get spendy. I use a laser temperature gun myself, to just check for an inordinately hot tire at the end of a travel day. It's not as good, perhaps, as monitoring on the road, but truckers use the guns as an option/addendum to tire thumping, and it works for me.
-Joel
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New tires going on now
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I took the first step today and went to Les Schwab to see what they had. What they are recommending is an 18 ply Michelin XZA2 Energy Low Profile Highway Tubeless tire in 275/70R-22..5. My current tires are Toyo's, 14 ply in 265/75R-22.5. The tires are very similar in size so I don't think that will be an issue.
What I need is more weight carrying capacity and these tires will boost me from 5200 to 6900 lbs per tire. My question is, is the 18 ply to much? Will the ride suffer by running this tire vs a 16 ply? I'm just concerned they may be too stiff.
The price is right and they are in stock. Thoughts please.
Thanks, Steve
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I forgot to add, that Schwab is recommending a product called Counterbalance, to run inside the tire for dynamic balalcing. It comes with a special valve stem that, reportedly, eliminates issues of something getting stuck in the stem that will cause the tire to leak.
My son-in-law's dad is a long haul trucker, who recommends centramatic balancers. Essentially, they bolt on between the duals in the rear, and on the steers, and have a tube on the outside that is filled with steel shot, I guess doing the same thing as the Counterbalance.
Anyone using either of these products? Opinions?
Thanks, Steve
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Just keep in mind, Steve, that weight carrying capacity is more than just about the tires. Never load your rig to exceed the chassis load ratings specified for your particular coach - GVWR and GAWR's.
I'll leave it to others with balancer experience to respond to your basic question, and several members are well-healed regarding your tire size inquiry ;).
-Joel
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You can't have too much tire. I'd opted for the high load range tire so they wouldn't have to be run at their maximum load capacity. As Joel stated, make sure youy never exceed the axle ratings.
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It will be impossible for me not to exceed the axle load ratings. The data plate lists the front axle capacity as 10400 lbs. When we had the coach weighed at Hendersons the front end without us in it was 10400. Same issue in the rear as the left rear is already at max capacity with just a few days worth of clothes and food. When this chassis was built they must have taken whatever they had laying around to build it and the engineer who designed it must not have bothered to figure out how much things were going to weigh.
Just about the only thing I can do is upgrade the tires. And we love the coach. It has its problems but I suppose every coach has something that isn't just quite right. So we've decided to live with it's short comings and just keep smiling.
I do appreciate the feedback so keep it coming.
Thanks, Steve
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Steve,
The Michelin tires sound like they will correct your overloaded tire problem, and Michelin tires are noted for their ride quality, so I do not think that you will notice a deterioration in your ride with the 16 ply rated Michelins.
As for as the Counterbalance to run inside the tires, I personally am not a fan of anything to run inside of the tire, although there are a lot of supporters for the product. I have my front tires spin balanced when they are installed, and have had no vibration problems with the four different sets of tires that I have had in the 11 years that I have been driving two different Beaver coaches.
Gerald
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Steve,
Tires are installed to support the anticipated load up to the axle's maximum weight rating. Axle ratings are not determined by the tire's capacity. The placard should indicate the lower of the tire capacity or axle capacity. In 2003 they increased the capacity to 12,800 for the front and 19K for the rear. You may want to see if your axles are actually rated at these numbers or more but were limited by the tires installed at the time. The problem with your rear axle is somewhat expected given it's a 40-footer with a single rear axle. That's the main reason I have a 42-footer with a tag axle. I only needed a 40-footer, but I know most 40-footers have very little rear axle cacapity left for personal stuff.
Gil
08 Contessa 42
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Steve,
The axle rating is calculated so that it does not exceed it's lowest rated component. In most cases on 1995 to 2005 model motorhomes, that component is the the tires. If you add up the load rating on your present tires, it will probably equal to your axle load rating. If this is the case, your axle and brakes may have a higher load rating than your tires do, so increasing the tire capacity will increase the axle capacity.
However that is hard to prove in case you have an accident caused by suspected overloading and someone can prove that your axle weight was higher than the listed axle weight rating for your coach. My 2000 Marquis exceeds the weight ratings that Beaver published for it on three of it's four wheel locations although none of my tires are overloaded because I changed to a higher capacity tire than Beaver originally installed on the coach. The 2002 Marquis had a higher weight rated front axle than my coach does, but the axles and brakes are identical, the only difference between the two coaches axles is the tires.
Gerald
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Thanks everyone.
Gerald, the tires available right now are 18 ply. Will there be an apprecialbe difference between the ride quality over a 16 ply tire?
Thanks again, Steve
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Steve,
I do not think that you will notice enough difference in the ride between the 18 ply rated Michelins and the tires that you are running now to be objectionable, they may even ride better. However the 18 ply will be a little more expensive than a 16 ply if it is available in that size and assuming that it has a high enough load capacity although the ride will not be appreciably harder.
The bottom line is that we have a very limited number of choices in tires that will fit our coaches that have the load capacity that we need. The peace of mind that you will have by knowing that your tires are no longer overloaded will more that offset any concerns about ride quality. A blow-out is much worse than a little harder ride. If the 18 ply rated Michelins are your best choice to prevent being overloaded, I would have installed them yesterday.
Gerald
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Some great advice proffered here, once again as usual, Steve. My only addition would be that if Les Schwab installs your new Michelins, I'd be sure that particular store is using the best available computerized balance machine available within the company. And keep taking the coach back if vibration exists.
Our coach had vibration issues right out of the gate at Bend when new. BCS techs discovered a couple of issues in the front suspension, fixed them, and then sent it down the road to the Redmond Les Schwab (their usual alignment and balance resource) for checking. Les Schwab rebalanced the front wheels, but some vibration was still evident.
The Bend Goodyear dealer alerted me to an issue Monaco had with Goodyear tires, supposedly out-of-round, but actually mismounted by Monaco. Goodyear had me take the coach to their Portland Service Center where they have state-of-the-art balance capability. They found the tires not mismounted nor out-of-round, but the Les Schwab balance way out of whack; they removed the unnecessary oversized lead, and rebalanced the front wheels for me for $75. Unfortunately the coach has had to remain parked since, but the 20 mile jaunt home from Goodyear revealed no noticeable vibration, and we look forward to our first full trip with a coach that finally floats down the road as "smooth as a Cadillac", as we used to say.
As much as I've had several decades of good results with Les Schwab sales and service at stores from Clackamas to Twin Falls, I offer the above word of caution. That's my story and I'm stickin' to it.
-Joel
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I replaced my factory-installed Goodyears after 4 years due to excessive river wear and a catastrophic front tire failure. I wnet with with Michelin Energy XZA2 in the same size. I much prefer the Michelins XA2's, I think they are a great tire. But they are a bit larger in diameter and began to rub away my wheel well liner. So against my wishes, I went back to Goodyears on the front. Watch the width and diameter and be sure that you have room for whatever new tires you buy.
When I installed the new tires I used Dynabeads (www.innovativebalancing.com) and I love the smooth balance ride they give. Follow their online instructions to a T and you will love the result. I plan to install Dynabeads on my car at the next tire change.
As for tire pressure monitoring system, I have had Pressure Pro for 7 years and I would not drive without it. It has been fabulous and trouble-free. And twice it warned me of a tire leak on my tow car. If I hadn't had those warnings, I could have run into big trouble. I am a believer. There may be other good tire pressure monitors around, but Pressure Pro has been nothing but great for me.
Marc, Wellington FL
2003 Beaver Monterey 40' triple slide
2010 Lincoln MKT toad
Unified Tow Brake
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I also had my tires replaced by Les With the Michelins. They recommended only balancing the front and went on to say that balancing the rear tires is not normally done so they only did the front. As I said this was their suggestion, I just went with what they suggested.
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I might add that I have noticed zero problems from only balancing the front and we are very happy with the Michelins.
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Well I pulled the trigger. Have an appointment next Tuesday to have 6 new Michelins installed along with a check up on the rear brakes. I'm looking forward to smooth sailing!
Thanks everyone for your advice. I really appreciated the input.
Steve
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Steve,
When Les Schwab installed my Michelins 3 years ago, they used a balancing product called Equal. It is a powder in a paper bag that disintegrates to disperse the power inside the tire. Every time you start the tires rolling, they re-balance. It feels like all the tires are perfectly balanced to me. They may have changed brands to Counterbalance.
Larry
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We got our new tires mounted on Tuesday in Hillsboro, OR then went to Ridgefield, WA for a chassis service, oil change, transynd conversion and generaor service. Wednesday we picked it up and loaded out. This morning we left Portland and stopped at 7 Feathers resort for the night.
What a difference the tires have made! Most of the wander is gone and what was a chore has become routine. Neither of us feel the ride is any different than before though the difference to me in just the ease of driving is well worth the the money we paid. We did opt to have the Counteract installed instead of the computer balance. Les made a mistake and put it in all the tires though we told them to only do the front tires so we got some free product! I think the jury is still out on the counteract. I front end seems to act the same as before so I'm not sure if the small vibrations I'm feeling are tire or road induced. Regardless, it is no worse than before.
Hopefully we can take a bit of time off from repairs and enjoy ourselves.
Thanks again to everyone for their help.
Steve