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Topic: Tires (Read 11354 times) previous topic - next topic

Re: Tires

Reply #240 –
Pierce, what I was wondering about, it seems a crack running the circumference direction of the tire, just inside from the tread.  I sure not saying it not a blemish, just what I saw in the photo and asking myself, if I had that would I know it safe?

I appreciate the photo.  I really like Michelin and I liked the idea of a 295 tire but think unless I could get a 295/70 it would rub?  Just do not like the idea of that but seems logical it only happens when turn sharp.  Wish I could get Herman Power to try one, take it off if rubs much.  My 275/80 Michelins are 1.75" from tire to base plate at ride height

Always appreciate your contributions to these technical discussions

mike

Re: Tires

Reply #241 –
Any new updates on the single rear tires.

Re: Tires

Reply #242 –
Quote from: Michael & Jackie –
Pierce, what I was wondering about, it seems a crack running the circumference direction of the tire, just inside from the tread.  I sure not saying it not a blemish, just what I saw in the photo and asking myself, if I had that would I know it safe?

I appreciate the photo.  I really like Michelin and I liked the idea of a 295 tire but think unless I could get a 295/70 it would rub?  Just do not like the idea of that but seems logical it only happens when turn sharp.  Wish I could get Herman Power to try one, take it off if rubs much.  My 275/80 Michelins are 1.75" from tire to base plate at ride height
mike
Mike,
The 275/80 Michelin and our 295/75 tires are the same diameter (within one revolution per mile at the most) and have about the same 1.75 inch clearance to the base plate. The 295/75s have almost 3/8" more width on each side at the tread. They probably would not rub at all but we spend a lot of time on unimproved roads crossing streams, making fairly steep turns off the main road into forest service campgrounds, etc. The coach is leaning over fairly far at this time. This is the only time it touches at all. In normal driving, it clears fine. The Michelin 275/80 might also touch in the same conditions. The touching is minimal and can't be seen on the tire, just a little polishing on the plate.

We do have some weathering on a couple of tires. It is very slight and using Bridgestone's examples of sidewall checking, cracking, damage, etc, it's almost in new condition. We will replace the front tires in a couple more years but not worried about it now.

Pierce

Re: Tires

Reply #243 –
John and Stacey, that beautiful coach deserves the very best shoes.  Hope that is what you have on him!

Pierce, by the charts I could reduce the psi about 10 if I went from a 275/80 to a 295/80.

By the charts I am to carry 110 psi in the Michelins 275.  A Michelin 295/80 would be about 98 psi.  I thought I might improve the ride with a bit lower pressure......

in fact, some techs with direct FOT experience say they would have sold/shipped it with 97 psi (odd, for not what Michelin chart says to use.....I cannot explain that versus the weight chart)

I do no see a Michelin chart for a 295/75 or 70 tire.

There are several options for the 275/80.  Both are maximum sidewall at 7160 lbs at 120 psi, but there is a little difference of less weight capacity at a given psi in X-Line, Energy Z, XPE2+, XZE tires versus the X Multi Energy tire.

The Michelin web site says I need or they recommend the XZE 2 tire, it has 6% wider tread than before (tire)


I did find this chart at tacomaworld.com.  As I recall though, this  varies by brand to brand, i.e. not all 275/80/22.5 are exactly the same?


                                  295/75-22.5             275/80-22.5                                   Difference
Diameter inches (mm)   39.92 (1014)               39.82 (1011.5)                     -0.1 (-2.5) -0.2%
Width inches (mm)           11.61 (295)             10.83 (275)                         -0.79 (-20) -6.8%
Circum. inches (mm)   125.42 (3185.57)       125.11 (3177.72)                   -0.31 (-7.85) -0.2%
Sidewall Height inches    8.71 (221.25 mm)       8.66 (220)                           -0.05 (-1.25) -0.6%
Revolutions per mile (km)    505.2 (313.91)       506.45 (314.69)                     1.25 (0.78) 0.2%

Re: Tires

Reply #244 –
Quote from: Michael & Jackie –
Pierce, by the charts I could reduce the psi about 10 if I went from a 275/80 to a 295/80.
By the charts I am to carry 110 psi in the Michelins 275.  A Michelin 295/80 would be about 98 psi.  I thought I might improve the ride with a bit lower pressure......
in fact, some techs with direct FOT experience say they would have sold/shipped it with 97 psi (odd, for not what Michelin chart says to use.....I cannot explain that versus the weight chart)
I do no see a Michelin chart for a 295/75 or 70 tire.
There are several options for the 275/80.  Both are maximum sidewall at 7160 lbs at 120 psi, but there is a little difference of less weight capacity at a given psi in X-Line, Energy Z, XPE2+, XZE tires versus the X Multi Energy tire.
The Michelin web site says I need or they recommend the XZE 2 tire, it has 6% wider tread than before (tire)
I did find this chart at tacomaworld.com.  As I recall though, this  varies by brand to brand, i.e. not all 275/80/22.5 are exactly the same?
                              295/75-22.5          275/80-22.5                                Difference
Diameter inches (mm) 39.92 (1014)            39.82 (1011.5)                  -0.1 (-2.5) -0.2%
Width inches (mm)        11.61 (295)          10.83 (275)                      -0.79 (-20) -6.8%
Circum. inches (mm) 125.42 (3185.57)    125.11 (3177.72)                -0.31 (-7.85) -0.2%
Sidewall Height inches    8.71 (221.25 mm)    8.66 (220)                        -0.05 (-1.25) -0.6%
Revolutions per mile (km)    505.2 (313.91)    506.45 (314.69)                  1.25 (0.78) 0.2%
Michael,
Sorry for the delay in responding.
This post covers several topics, all related to each other.
Aspect ratio: This is the relationship of the width of the tire to the height (not diameter) here is a quote I modified to suit our sizes:
"The two-digit number after the slash mark in a tire size is the aspect ratio. For example, in a size 295/75-22.5 tire, the 75 means that the height is equal to 75% of the tire's width. The bigger the aspect ratio number, the taller the tire's sidewall will be."

So, while a 275/80-22.5 Michelin and a 295/75-22.5 SOB may have a different aspect ratio, the diameter is almost exactly the same. The 6% wider Michelin you mention would just about make up any width difference between the two different sizes and aspect ratios. Translation; if the airbag plate rubbing were related to the width, the wider Michelin would also rub. On our coach, it's possible the regular Michelin might also rub in our "off road" excursions because of leaning, etc.

As Brett had earlier posted, the (for simplicity) limits of steering travel is adjustable in case that might be the cause of the tire rubbing on the airbag plate.

The installed position of the front "I" beam suspension may not be the same on all coaches. If not exactly correct (too far forward), it could cause the tire to touch in certain positions.

As the aspect ratio number drops (along with the tire height), the tire has less distance (height) to flex so lower profile tires tend to have a harsher ride. Cars we see with super low aspect ratios on the street today have suspension changes (progressive shock absorbers) to soften what would be normally a harsh ride. Lower aspect ratio tires do handle better as they flex less and have a larger "footprint" on the road. The handling quality is also dependent on the tire quality and design.

Tire sidewall design will also effect the ride with more flexible sidewalls giving a softer ride. Michelins are noted for a very flexible sidewall. Others like our Coopers, have a more rigid sidewall and may have a firmer ride. Both have their pros and cons.

There will always be disagreement between recommended tire pressures. You will just have to figure out what make you feel good after considering the charts, placards, tire load rating, etc.

An uncomfortable ride can also be caused by a damaged shock absorber. Tires may also be blamed when the problem is incorrect front end alignment. Different brand tires may be effected more or less by incorrect front end alignment.

Pierce

Re: Tires

Reply #245 –
Pierce
As you suggested I Tried 110psi on the new toyos , happy with a firm more connected ride , as you also mention the ride became a little more compliant when carrying full tank of propane , diesel and fresh water .
Overall I am happy with the new tires and would recommend them .

Re: Tires

Reply #246 –
Pierce, I met with Frank at Herman Power.  They offer many brands and sizes.  For example Uniroyal now makes a truck tire, about half the price of a Michelin.  They have Toyo and others.

He recommended the XZLA tire in 275/80/22.5 H.  I was thinking about the XZE 2 until I talked to Don Hay.  The XZE 2 has about 6% wider tread than the XZA 3+ I have.  The XZLA is said 5% more energy efficient than the XZA3+ it replaces and the tread looks much the same.  Michelin web site lists differences between the tires, load ratings seem identical. 

My  XZA3+ rubs on very tight turns.  I can feel it but do not see it doing any damage. But a wider XZE 2 or a 295 I guess would rub a bit more.  Wish I could just try a 295, still like that idea.

I asked Power if I could turn the outer dual valve stem outward.  He agreed.

Don Hay got two XZLAs for the front, has Toyo already on the rear.  Don said the dealer used a kevlar valve stem extension on an inner dual stem that was leaking, replacing a steel one.  New idea to me.

Thanks all.....

Re: Tires

Reply #247 –
Michael,

The wider tire might or might not rub more. You should try and find out what part of the tire rubs. If it's the middle portion, the wider tire won't make any difference. Ours only rubs in unusual attitudes so it might be good to find out what is unique about your coach rubbing on very tight turns.

Pierce

Re: Tires

Reply #248 –
Has anyone had any experience with Koryo, Double Coin, Road Warrior or Samson Tires? All of a sudden I see a bunch of ads for these tires.

Re: Tires

Reply #249 –
Have heard of Samson before.
John

Re: Tires

Reply #250 –
I had bad luck with Samson but it could have just been a one time incident. The sidewall gave up after just 2 years.

Re: Tires

Reply #251 –
I would steer clear of Chinese tires, they have a tendency for substituting inferior materials and "cooking the books" after "testing" has been approved. Kinda like the mystery meat you get at the Chinese buffet. Kinda looks like beef, kinda tastes like beef, but it's got this weird wang you can't quite identify. BTW where did all of the radioactive steel from Chernobyl disappear to, you guessed it, Chinese contractors salvaged it.

Re: Tires

Reply #252 –
I am not a fan of "China-Bombs", they have been heavily used on 5th wheels.  Prone to parts being left on the highway and many conversations in their forums.

John

Re: Tires

Reply #253 –
I've got a few Sampson tires on one of my pick-ups. I have them because of tire failures on the road and it's an unusual size and it's what the random dealers carry. I've had a problem with one that would not balance and one was maybe out of round or had a cord failure. The good ones are okay. Seems I have blowouts in up state NY and Penn. because of bad roads and have to get replacements where I can. As I said the good ones are fine, the defective ones maybe mean that the QC is not too good at the factory.


wantabe

Re: Tires

Reply #254 –
Lots of tires made in the U.S. but Goodyear is about the last American company left with Cooper under foreign ownership since purchased by an Indian firm in 2015

Here is where the tires tested by Consumer Reports are made: Where Are Your Tires Made? - Consumer Reports

How to read the DOT codes for country of manufacturer, date, etc: Which Tires are Made in the USA? | Tundra Headquarters Blog

Interesting that with all of their Michelins, none were made in France.

Pierce

Re: Tires

Reply #255 –
decided to replace with these tires, got six today.

Michelin, 275/80/22.5, Z X Line energy (XLEZ H), Made at Michelin in Canada, 15/17 date

Highly recommend Steven at Herman Power for installation service.  Explained to me what he found when removed the old, how the valve stem fits in a steel dual inner wheel, asked what pressure I wanted and he said is exactly what he would have used if I  not known, 110/90 psi.

good hunting.  and thanks Pierce for the other code info.

Re: Tires

Reply #256 –
Quote from: Dave Katsuki –
Well I got experience with the 295/75R22.5 M154 Toyo's from Tucson up to Prescott, and unfortunately the front tires were rubbing the airbag platforms (and the airbag when it was compressed going around a corner.)

Dave: Do you know why your Toyo  295/75R22.5 M154 tires were rubbing on the front.
Other folks have posted that Toyo  295/75R22.5 M177 tires are OK on the front.
Is the rubbing Toyo M154 occurring because the M154 is wider than the M177, or is your front axle different (or configured differently) than the other coaches which can run 295 M177 tires?

A Toyo dealer in Victoria told me that the Toyo M154 tires is better for a motorhome than a Toyo M177 because the M154 is more stable.

Re: Tires

Reply #257 –
Quote from: P. Wyatt Sabourin –
Quote from: Dave Katsuki –
A Toyo dealer in Victoria told me that the Toyo M154 tires is better for a motorhome than a Toyo M177 because the M154 is more stable.
Wyatt,

Wonder what he meant by "stable?" Good catch all word but think we need a better description than that. Might be good to call the U.S. headquarters and ask what the difference might be.

Pierce

Re: Tires

Reply #258 –
Michael and jackie:  my exact weighed tire pressure on my fronts with LRH Xza-3+ is 97 psi.

The driving experience was noticeably different at changes of 5 pounds max.  Many oweners swore they could tell 2 psi.

Smoother ride is why I went LRH instead of the LRG that actually was within specs.

Difference was minus 10 psi for the same loads. 

My rears are 87 btw

Re: Tires

Reply #259 –
When I read the tire model descriptions on the Toyo website, there appeared to be little difference between the M154 and M177, however, the M154 has a deeper tread and is better in "highest-scrub environments".

M177
LONG-HAUL STEER TIRE
The M177 is a deep 18/32" steer tire designed for long-haul operations. The excellent wear in miles per 32nd with minimized irregular wear, combined with the deep 18/32" tread depth, results in maximum removal mileage.

M154
LONG-HAUL, REGIONAL, AND URBAN DEEP ALL-POSITION TIRE
The M154 is a deep all-position tire designed for regional and urban service in the highest-scrub environments. Excellent, even wear in miles per 32nd and a deep tread up to 22/32" deliver maximum removal mileage, even in the drive position.

I believe by "highest-scrub environments"  Toyo is referring to a unique buttress protector designed to reduce cutting and curb damage to the sidewall.

My choice based on these descriptions would be the M177 (18/32 tread) for my motorhome, not the M154 (22/32 tread) because I will never wear out the 18/32 tread, while less tread equals less diesel per mile. Also, I do not often rub my tires on curbs so do not need the a high scrub tire.