Mixing 12R22.5 and 275/80R22.5 Tires?

[OneLapper]

Keep looking for take offs.  At work the tire reps always seems to have deals on this or that.  Sometimes it new tractors delivered with tires the buyer didn't spec, etc. You might a;so want to look at Hankook 12AHs, I use them on my 4106 and I'm happy with them.  We have owner operators with 2016 Volvos with 156" ARI sleepers using Hankooks.  It's a good, inexpensive tire.

[luvrbus]

If you are member of FMCA you can get deals on new Continental Tires

[GnarlyBus]

Thanks for the leads guys! I've heard about the FMCA deals. Maybe I'll look into them again.


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[TomC]

275/80R-22.5 is an 517rpm tire. 12R-22.5 is an 485rpm tire. You'll loose about an inch of ground clearance. And if you typically have 3.70 rear end ratio, then the 12R-22.5 will give you 1795rpm at 60mph. The 275/80R-22.5 will give you 1913rpm at 60mph.
I would look for 11R-22.5 take off's with around 50% tread left for drivers. That will give you a 500rpm tire or 1850rpm at 60mph.  Good Luck, TomC

[Zephod]

275/80R-22.5 is an 517rpm tire. 12R-22.5 is an 485rpm tire. You'll loose about an inch of ground clearance. And if you typically have 3.70 rear end ratio, then the 12R-22.5 will give you 1795rpm at 60mph. The 275/80R-22.5 will give you 1913rpm at 60mph.
I would look for 11R-22.5 take off's with around 50% tread left for drivers. That will give you a 500rpm tire or 1850rpm at 60mph.  Good Luck, TomC

You sound knowledgeable. I have a bus that had originally 9R20F wheels. I'm not sure of the circumference of a 9R20F. Somebody changed the wheels to Dayton hubs. I'm not sure they changed the speed sensor in the transmission because there was an additional speed sensor on the prop shaft. Since that additional sensor is not working, I'm wondering what metric 22.5 would be equivalent to the 9R20F.


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[kyle4501]

7 year old tires aren't worth much more than the cost of mounting them.

The biggest problem is you don't KNOW the history of them. Overloaded? Run with low air pressure? Ever been flat with a load on it?

I have had tire failures at speed on the road. I DO NOT want another one ! ! ! !

In my opinion, Take offs are a much better option - especially if you have time to wait . . .

[luvrbus]

You sound knowledgeable. I have a bus that had originally 9R20F wheels. I'm not sure of the circumference of a 9R20F. Somebody changed the wheels to Dayton hubs. I'm not sure they changed the speed sensor in the transmission because there was an additional speed sensor on the prop shaft. Since that additional sensor is not working, I'm wondering what metric 22.5 would be equivalent to the 9R20F.


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The 275/80x22.5 is the metric equal to a 900x20.I just went through this on my firetruck the bias is 41in in diameter and 506 revs per mile,the steel radials were 40in in diameter with 519 rev per mile.
I went with the steel radials only because they were tubeless and would work on my Dayton wheels with the lock ring (Double Coin Brand).For 6 it was $1245.00 out the door at RedBird Tire in Phoenix.
Since it is hardly ever driven I didn't want to spend $3000.00 + on a name brand set of tires,fwiw the 900x20 is a very popular tire size for military vehicles but not so much in the private world
     

[Branderson]

7 year old tires aren't worth much more than the cost of mounting them.

The biggest problem is you don't KNOW the history of them. Overloaded? Run with low air pressure? Ever been flat with a load on it?

I have had tire failures at speed on the road. I DO NOT want another one ! ! ! !

In my opinion, Take offs are a much better option - especially if you have time to wait . . .

I've been under the impression that tires should be replaced at 7yrs just to be safe.

[luvrbus]

Michelin warranties there bus and truck tires for 7 years some up to 10 years with up to 3 recaps in 700,000 miles I don't think it all about safety more like selling you more tires JMO 

[DoubleEagle]

Michelin warranties there bus and truck tires for 7 years some up to 10 years with up to 3 recaps in 700,000 miles I don't think it all about safety more like selling you more tires JMO 

Yes, there is more concern about sales than safety. It's sort of like the mattress companies that now say you should replace your mattress at eight years. I have had tires and mattresses that were older than ten years in the same vehicle. 

[kyle4501]

I've been under the impression that tires should be replaced at 7yrs just to be safe.

For the steer axle, I'm not comfortable past 5 years.

For the drives, I would go 7 & the tag, a little more.

However, this is MY comfort level based on personal experience and the advice from friends in the heavy hauling business.

Your opinion is likely to be different, at least make it a well informed one.   

[luvrbus]

Nothing is going to change since this comes up every 6 months people are going to run what they can afford some believe in Michelin's golden rule some don't that is the way we are.
LOL heck I even use never seize on my lug nuts.
Walter makes a good point about mattresses and tires we have a Duxiana mattress no way will I be buying one of those every 8 years in spite of all the mattress sale pitches.Point is you make the call what is best for you not a tire manufacture.
They don't make billions of dollars being concern about you they sell tires or they could build a tire that would last.
You don't see the military popping for tires every 7 years my Hummvee is 1991 model and still has the original tires goes to show you they can build a better tire              

[TomC]

For the 8 new drive tires on my bus, I deviated from Michelin and bought Hankook. I figure that Freightliner has them as a standard tire offering, they can't be that bad. Plus almost $2,000 cheaper. The tires that were on the truck were 19 years old (truck has sat). Because I used Never Seize on all inner and outer wheel nuts, none locked up-all 80 came off and on without problem. Good Luck, TomC

[Branderson]

I'm sorry but the mattress analogy doesn't hold water for me.  What exactly is the risk of using an old mattress.......

Anyway, everyone has an opinion on tires including me...I'm just going off of my uncle who changes all tires every 7yrs no matter what and he has been a full timer and drove trucks before that. 

[luvrbus]

Any of you guys old enough to remember when a tire was warrantied for the life of the tread dates had nothing to do with if the tire blew they measured the tread deducted a amount and gave you a new tire no matter how old the tire was