Tires

[hello_im_alex]

If I am replacing 10R22.5 tires is it absolutely essential that the tires are the exact same size? I can only seem to find 9R22.5 and 12R22.5

[chev49]

Standard sizes are 11x22.5 and 12x22.5. You should a least run the same size tires on each axle. For example 11's on fronts and 12's on drivers if you have some of each. Normally people run the same size on both axles, but many forget to match up the circumfrence of the tire.
The circumfrence is what is actually important. That's why you should determine revolutions per mile (like 475) when you match your tires up.
As a non bus example, yesterday I bought another car trailer without a spare. It had smaller size 15 inch tires, and all i could find was a 14 inch rim in my wheel stack, but i found a 235 x 14 i think, tire that was about the same circumfrence as the 15 inchers.

[TheRainbowBoxer]

A big reason it is important to match tire circumference on drive (rear) tires is that otherwise the differential will wear out prematurely.

The differential is a device in your rear axle that allows your driven tires to turn at different speeds to keep the tires from wearing out when you make turns (since the tire on the outside of the turn needs to travel farther).


*edited for clarity (should not post when tired <- no pun intended)

[Elliot Naess]

Alex, do not use smaller tires like the 9R22.5. That would reduce your weight carrying capacity and could get you in trouble.

You can use larger, like 11R22.5 or maybe even 12R22.5, but ONLY IF your rims are wide enough. The tire shop can look up the minimum rim width for a given tire size.

But this type of numbering of tires is becoming obsolete. Modern tires are more often numbered by the Metric system. My bus came with the old 10 or 11 type, but now it has 295/75R22.5. Old truckers refer to these as Low Pro tires -- low profile. The tire shop should be able to tell you what Metric size will match your old 10 size.

You can use recapped tires on the back, but not on the front.

[hello_im_alex]

Would a tire that looks like this be able to be retreaded in your opinion? or is the damage too much? thanks!

[bus-bro]

No! What's the date code on the tire?

[Elliot Naess]

Originally Posted by hello_im_alex

Would a tire that looks like this be able to be retreaded in your opinion? or is the damage too much? thanks!

Qualifying a tire for retreading is a science. They use X-rays and such. And as Bus-bro says, it may simply be too old. Tires die slowly but surely from age and sunlight. But you can buy recapped tires outright.

[chev49]

you also can run 24 inch rims ... I have 22 inch ones, but will change over to the others if i find enough wheels. It will change my gear ratio a but, but will turn the engine a bit slower while driving.
New tires are metric of course.
With a used tire, i think they will not cap one that is older than about 5-6 years here. They will cap tires that have chunks out of the tread, cause all they use is the casing, but not old or weather checked ones like pictured.
Last time i went to the recap place 6 months ago, i didn't see an x ray machine... maybe they have one now..

[Elliot Naess]

Chev49, you got me thinking. X-ray may not be the correct term. According to Wikipedia, the technology is called Shearography. And there may very well still be shops who do only visual inspection. But I would not trust my tires to anything less than the best inspection available. You still save a ton by buying recaps.

[bapos]

I just came from a a job where I was a fleet account manager for some very large shipping fleets.... swift, Old dominion, Fed Ex Nation and I worked for a subsidery of Michelin so Yes... I am going to pitch them cause I think they make th best retread on the market. The center I worked for did also have a retread plant attached to it so yes, I have a very person and hands on prospective on the subject.

Do not be afraid of retreads on your bus... do not put them on steer axels. Dollar for dollar they wear the same as a new tire and depending on the tread some of them come in a deeper tread then a new one ... well michelin in som cases.

As for xray or Shearography, not all retreaders use it. I know in my old plant they used it on every tire that came out of their plant. Another reason why I am very pro michelin. A lot of the competitors do not scan every tire.

As for some of the pics I saw on this thread. As long as your DOT meet spec you should be ok. There is no issues with the weather cracks on those tires. I use to sort about 400 casings a day so I would like think I have knowledge on the subject.

Any questions please let me know.