skyking8

Replacement Tires

17 posts in this topic

Getting some new tires for my rig is becoming a job. Current I have Michelin 275/80R22.5 all around. I only want to replace the front drive tires and one outside rear. I have found that size tire isn't all that common a stock item for a distributor even in Goodyear; not to mention that Michelin is $125 more per tire.

Different manufacturer for the drive tires isn't an issue, but so as not to mix tires on the rear, I would be stuck buying a Michelin. I have a notion to just replace all six with something else that are less expensive. At a savings of $125/tire and a small trade-in allowance, it seems reasonable. I usually only drive 10K/year.

Because of fender well clearance, I couldn't resize up, but could go down. I wonder how that would work?

Has anyone else had this problem?

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Getting some new tires for my rig is becoming a job. Current I have Michelin 275/80R22.5 all around. I only want to replace the front drive tires and one outside rear. I have found that size tire isn't all that common a stock item for a distributor even in Goodyear; not to mention that Michelin is $125 more per tire.

Different manufacturer for the drive tires isn't an issue, but so as not to mix tires on the rear, I would be stuck buying a Michelin. I have a notion to just replace all six with something else that are less expensive. At a savings of $125/tire and a small trade-in allowance, it seems reasonable. I usually only drive 10K/year.

Because of fender well clearance, I couldn't resize up, but could go down. I wonder how that would work?

Has anyone else had this problem?

A couple of cautions here (most of which I think you are aware of):

Never put tires of different diameters on one side of a dual-- the "taller" tire will carry most of the weight. This means not only don't mix sizes, but also don't pair an old tire (less tread) with a new one (more tread).

If you consider a different than OE tire, make sure that it is of the same load carrying capacity or higher than the original.

Brett

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A couple of cautions here (most of which I think you are aware of):

Never put tires of different diameters on one side of a dual-- the "taller" tire will carry most of the weight. This means not only don't mix sizes, but also don't pair an old tire (less tread) with a new one (more tread).

If you consider a different than OE tire, make sure that it is of the same load carrying capacity or higher than the original.

Brett

Brett, I am going to be in the market for new tires shortly as well. I was looking at going from 255 70R22.5 to 275 70R22.5. Looking at the specs on the tires they are basically similar except the 275's are 1.3" larger in diameter and .7" larger in width. They are a load rating up H to J and can carry 1400lbs more in a single location. I'm not looking at carrying more weight and will stay within the axle weight rating. However I could carry my existing weight at a lower psi example 4900 lbs would reduce the psi requirement by as much as 15 psi. The other issue would be my speedometer calibration which I would have to look into.

I recently put the Ride Enhancement Kit on my coach from Source Engineering and it helped. I was thinking going this route would help smooth out the ride even more.

Any thoughts?

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Brett, I am going to be in the market for new tires shortly as well. I was looking at going from 255 70R22.5 to 275 70R22.5. Looking at the specs on the tires they are basically similar except the 275's are 1.3" larger in diameter and .7" larger in width. They are a load rating up H to J and can carry 1400lbs more in a single location. I'm not looking at carrying more weight and will stay within the axle weight rating. However I could carry my existing weight at a lower psi example 4900 lbs would reduce the psi requirement by as much as 15 psi. The other issue would be my speedometer calibration which I would have to look into.

I recently put the Ride Enhancement Kit on my coach from Source Engineering and it helped. I was thinking going this route would help smooth out the ride even more.

Any thoughts?

Mikev,

There is too much here that is coach specific in terms of tire to chassis and tire to coach clearance for me to be able to give advice. Hopefully, others with the same chassis and coach (you might post specific information on your chassis and coach, as others may have the same model or a different Monaco product on the same chassis) who can give you specific information.

I would also ask this question of Monaco and of Source Engineering, as they may have first hand experience with this upgrade.

Brett

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Mikev,

There is too much here that is coach specific in terms of tire to chassis and tire to coach clearance for me to be able to give advice. Hopefully, others with the same chassis and coach (you might post specific information on your chassis and coach, as others may have the same model or a different Monaco product on the same chassis) who can give you specific information.

I would also ask this question of Monaco and of Source Engineering, as they may have first hand experience with this upgrade.

Brett

Thanks anyway Brett, the tire clearances based on my observation would be fine, plenty of room. I'm more interested in whether the larger-higher load rated tires would be a softer ride at 85 psi than my spec tires at 100 psi carrying the same load... I might ask Michelin if the J rated tire would be naturally harder even at the lower psi. Interesting subject. If I find something I'll let you know.

Cheers

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Thanks anyway Brett, the tire clearances based on my observation would be fine, plenty of room. I'm more interested in whether the larger-higher load rated tires would be a softer ride at 85 psi than my spec tires at 100 psi carrying the same load... I might ask Michelin if the J rated tire would be naturally harder even at the lower psi. Interesting subject. If I find something I'll let you know.

Cheers

Mike,

When you say the clearances are fine, have you considered the spacing between the rear duals? Tires that are wider will reduce the space between the rear duals. This space is critical to the tire function. The heat shared between the rear duals is the reason that they are rated at a lower weight carrying capacity than an individual front tire. If the space is less than required it can increase heat and result in tire failure. In a worst case situation, the rear duals can rub or scrape against each other causing guaranteed failure. This scrubbing happens as the tires make road contact and bulge slightly. An increase in width of 0.7" on two tires reduces the spacing between the tires by 0.7" which might seem small but there isn't that much distance to begin with. Running at a lower pressure may increase the bulge and further increase problems. I'd consider this change very carefully. Get some good advice from a tire expert and/or your manufacturer before making the change.

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From a reputable tire dealer in Washington, when I had a blow-out, a 255/80R22.5 cost me $463 each.

What price have you been quoted?

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Never put tires of different diameters on one side of a dual-- the "taller" tire will carry most of the weight. This means not only don't mix sizes, but also don't pair an old tire (less tread) with a new one (more tread). Brett

Actually, I had not thought of the tread issue. What's worse neither of the two large tire dealers mentioned it either. This is really becoming a job.

I spent a couple hours looking doing some research for tires online..mostly wasted time. Perhaps I need to contact a manufacturer's rep and discuss the issue with them. Who is out there besides GY and Michelin?

Maybe someone can recommend a top notch tire dealer in the central US. Perhaps one that is a FMCA commercial member.

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Wingfoot Commercial Tire is a nationwide Goodyear tire dealership. I've purchased tires through them four times. Three times I've been quite impressed with their knowledge and professionalism. At the fourth shop, I felt like I had to train them in how to mount a steer tire, they wouldn't have checked for round or corrected an out of round tire unless I told them what to do next.

Don't go to Wingfoot in St. Paul, MN!

I've gone to a shop (TDS) recommended by Cummins in Denver - results weren't good. They cracked one of my aluminum rims (ouch) by over-tightening it. The vibrations in the steer tires were not resolved because they didn't check the roundness of the tires. Both these were pointed out at a Freightliner shop in Phoenix. Later a Wingfoot shop explained why the tires were so out of round and it related to the method of mounting them TDS used.

The long and short of this is that I'd have a hard time recommending a shop. A key person may have left or retired and the knowledge is very hit and miss. Good tire people are hard to find. The Wingfoot shop in Kansas City, MO did a fine job for me. The Wingfoot Shop in Fresno, CA gave me some good tips on mounting steer tires. I'd recommend either of these.

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First, I would highly recommend GY tires. I have GY on the drive and Michelin on the steering and tag. I just don't see anything worth the extra dollars to justify putting Michelin all 'round. We are due for new tires on all 8 and I will be installing GY's.

Second, if you want to ruin a brand new tire, install it as a single on a set of duals. When you drive you wear down the tread (fairly equally). Install one new tire beside that worn tire and you have 2 tires of different sizes. That simply does not work. If you have to replace one tire in a set of duals then you need to replace the set. Maybe you can move the one "good" tire, but you sure don't want to leave it in place and put a bigger tire on beside it.

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Wingfoot Commercial Tire is a nationwide Goodyear tire dealership. I've purchased tires through them four times.

My son-in-law buys all of his company's heavy equipment tires from them. Just so happens that there is a Wingfoot about an hours drive from my home which is where I'm headed at the end of the month.

Thanks Tbulter. I think I see light at the end of the tunnel. Hopefully, the current tires will get me to it. :rolleyes:

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My son-in-law buys all of his company's heavy equipment tires from them. Just so happens that there is a Wingfoot about an hours drive from my home which is where I'm headed at the end of the month.

Thanks Tbulter. I think I see light at the end of the tunnel. Hopefully, the current tires will get me to it. :rolleyes:

Since you will likely replace them based on AGE, not miles, make sure that they are not over 6 months old-- and newer than that is better.

Last four digits of the code on the sidewall beginning with DOT.............. indicate the WEEK and YEAR of production. Example: DOT...............1110 were made the 11th week of 2010.

Brett

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I have an 2006 Alfa with gross wt. listed as 32,000lb. I am going to buy new tires and want Michelin. My tires are 275.80R.22.5. I can't find this size listed on the Michelin website. Any advise about going to a different size?

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Ratings for a Michelin 275/80R22.5 are interesting

The LR-G at 110 psi is rated at 6175# Single and 5675# Dual

The LR-H at 120 psi is rated at 7160# Single and 6610# Dual

The Michelin specs show both LR-G and LR-H at 40.1 OD and 10.9" wide when measured on a 8.25 wide rim with a 12.2 dual minimum spacing. The dual spacing is controlled by the wheels so you will need to contact the wheel mfg. You can learn more of wheels at http://www.rvtiresafety.com/2011/12/wheel-is-just-wheel-isnt-it.html

What is interesting is that industry standards show a 295/75R22.5 with the same load capacity in LR-G but slightly lower load capacity at LR-H 6610# and 6005#

The 295 normally has an OD of 39.92 and width of about 11.4 if olso on a 8.25 rim so the warnings on dual spacing are something you really need to consider to avoid problems.

RE matching duals. You should ALWAYS measure the OC of any tires you are considering mating as a pair. The OC must be within 3/4" of each other or you are asking for trouble. Do not count on the larger tire wearing down faster to get a matched pair. Deeper tread runs hotter. The larger tire is a dual pair will carry more load so this adds more heat. heat is the number one ennemy of tires.

One thing to include in your investigation is the real load you carry on each end of an axle. You should never consider going down in load capacity as even if you always run light load the next owner may laod his bowling ball collection and just assume the tire size you selected is OK. The next owner could have tire failures because of your decisions.

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What does it mean getting a tire out of round? What does a tireman have to do to get it " in round"?

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Out of round means that the tire is "egg" shaped instead of round. Tire dealers have RUN-OUT GAUGES that can very quickly measure how "out of round" it is.

For front tires, MY specs are no more than .035" run out. Run out can be in the circumference or side to side.

If more than .035" run out, it is common to deflate the tire and remount it 180 degrees around the wheel and recheck.

If that doesn't do it, you have a choice of TRUING the tire or getting a new tire. Do not be afraid of having the tire trued-- I have all my front tires trued, as do many OTR truckers. Totally round (from truing) will run longer and smoother than even a slightly egg shaped tire, so the little rubber that is shaved off the high points is not a problem.

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