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

[GnarlyBus]

Is it a problem in a bus conversion to put 275/80R22.5 tires (Michelin XZA3 Low Profile) with a Max Load of 7,160 on the the drive axle and keep the 12R22.5 Steer and Tag tires the same? My drive axle tires need replacing and I found a really nice used set of 4 Michelins locally. So 4 of them with matching tread depths would be on the drive axle. I know it will affect my RPMs a little bit, but is it safe?

If I had more money, I'd splurge the 4k for new tires all around, but this might have to do for now...

[GnarlyBus]

Just found this note in the MC-9 Manual. So it seems that Low Profile tires were used by some.

[Oonrahnjay]

   The Michelin book says 501 - 518 rev/mile difference.  That's about 3% slower (or 2 Miles/hour) for the low profile.  Unless you're critical on your gearing and engine revs now, that should be OK. 

[Dave5Cs]

My drive axle tires need replacing and I found a really nice used set of 4 Michelins locally. So 4 of them with matching tread depths would be on the drive axle.

Same tread depths? but what is the date codes( how old are they) It will say DOT and then the week of the year and the year.

[GnarlyBus]

Same tread depths? but what is the date codes( how old are they) It will say DOT and then the week of the year and the year.

It looks like they're from 04/10.

[Zephod]

I see a wide variety of tyres used on the work busses. The Dayton hubs had metric, imperial and a whole lot of different metric sizes. Certainly a different size might mean a different speed but that's a non issue.

My bus has 10R22.5 on the front, 11R22.5 on the back and was built originally for 9R20F. Somebody change to Dayton hubs. I have no idea how accurate the speedo is. I know somebody put another speedo on the drive shaft. It was so badly connected with dangling wires that I cut the wires off and installed a GPS speedo until I can figure out if the original Allinson speedo still works.


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[Dave5Cs]

Those IMHO are dated out. Tires rot from the inside and 7 years or before is time to change them.

[Zephod]

Those IMHO are dated out. Tires rot from the inside and 7 years or before is time to change them.

Agreed though I mentioned a date code on a bus tyre at work, which was 10 years old and he was alarmed. Then he asked if it was front or rear. I told him rear and he said it was nothing to worry about and that it'd probably never be retreaded again.


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[GnarlyBus]

Those IMHO are dated out. Tires rot from the inside and 7 years or before is time to change them.

They're replacing tires just over 10 years old!  I'm seeing 10 years max online but 7 is probably a better number. I'll look for newer when I do the steer tires.

[Zephod]

They're replacing tires just over 10 years old!  I'm seeing 10 years max online but 7 is probably a better number. I'll look for newer when I do the steer tires.

Steers... brand new only, too important.


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[GnarlyBus]

Yah, that's what people say. I guess their replacing them every trip? After one trip or 4 years, they aren't brand new. Surely replacing what I have would at least be a step in the right direction in terms of safety. I'll see if I can get them new. I'm not going to use re-treads, but maybe I can find some that are a year or two old. $500 a tire is quite a big price for a bus that sees maybe 2k miles a year. Maybe if you guys see an MC9 with Blue and Red Stripes, just stay a safe distance away.

Which brings me to a short observation (not directed at you Zephod), I'm noticing often on forums there seems to be a group of people for whom money is not an issue. They can't seem to understand why others problems are problems when they could be solved with a $5k set of new tires or a trip the DD Dealer every Spring and Fall. They might say that if you don't have $30k in that bank for a breakdown or a barn full of spare buses, you shouldn't be in the busnut game. I've come a long way in the last few years and have ardently read these forums and studied the MC9 and 6v92 Manual like they're Bibles. I appreciate the wisdom of everyone on this forum, except that one guy the other week who wanted...nevermind.

Not trying to start anything, just speaking my mind. I do appreciate this forum a lot.

[Dave5Cs]

Not me either. I have 6 tires compared to your 8 so it is $1,100.00 less. I saved up and didn't put the bus on the road until I could afford safe tires. Only reason I got new was couldn't find any old ones that were any good or wrong size etc. Not a rich man either. Was only letting you know what you were looking at because you did not say anything about the dates, you only mentioned the tire tread which is good but not as important.

Yes you could get away with tire that are 10 years old on the rears but not as safe as 7. But I agree not on the steers. If you have a zipper rip they go down immediately and caused a lot of damage to a bus if you happen to be on the freeway going 60 to 70 MPH as well as tire fires, wipe out airbags, brake lines etc.
So nothing more than for your information. Do with it what you want.....

[Zephod]

Yah, that's what people say. I guess their replacing them every trip? After one trip or 4 years, they aren't brand new. Surely replacing what I have would at least be a step in the right direction in terms of safety. I'll see if I can get them new. I'm not going to use re-treads, but maybe I can find some that are a year or two old. $500 a tire is quite a big price for a bus that sees maybe 2k miles a year. Maybe if you guys see an MC9 with Blue and Red Stripes, just stay a safe distance away.

Which brings me to a short observation (not directed at you Zephod), I'm noticing often on forums there seems to be a group of people for whom money is not an issue. They can't seem to understand why others problems are problems when they could be solved with a $5k set of new tires or a trip the DD Dealer every Spring and Fall. They might say that if you don't have $30k in that bank for a breakdown or a barn full of spare buses, you shouldn't be in the busnut game. I've come a long way in the last few years and have ardently read these forums and studied the MC9 and 6v92 Manual like they're Bibles. I appreciate the wisdom of everyone on this forum, except that one guy the other week who wanted...nevermind.

Not trying to start anything, just speaking my mind. I do appreciate this forum a lot.

I tend to agree. I've noticed that. People telling me I should have $2,000 worth of solar panels, $3,000 worth of batteries, a professional paint job and pay people to do this, that and the other.

Some brag to say they spent $60,000 on their conversion and get very pissy when I suggest a used motorhome would have been better value.

I priced new tyres for my motorhome. They come in at about $200 each as the lowest cost. The highest is about $500 each. Given that we don't do that many miles, cheap tyres are better value because they're not even going to have 10k usage before they're changed out at 7 years old.

Mind, the question also is whether we will still own our motorhome in 2,3,4,5,6,7... years.


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[PP]

Money is always an issue with me, whether I have it or not. And even when I do, I like a deal. IE- Refried beans on sale 2 for a dollar. There goes a hundred bucks-thank Goodness for large bays. See how owning a bus can save you money    PFFFT Whoops, sorry....

[Zephod]

Money is always an issue with me, whether I have it or not. And even when I do, I like a deal. IE- Refried beans on sale 2 for a dollar. There goes a hundred bucks-thank Goodness for large bays. See how owning a bus can save you money    PFFFT Whoops, sorry....

Have you considered converting your bus to run off methane :p


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