Happy Sunday all.
Clifford reminded me about a question I wanted to ask in a comment on a different thread.
I currently have 12R 22.5 tires on the bus. I have been thinking of changing them to 24's, but I wanted to get input from you all.
I know the effect of different tires on cars and Jeeps, but rather than assume, I thought I'd ask.
Thoughts?
Which one is most easily available on the road?
My old long gone Crown Supercoach had 12R 22.5 tires. Some help here please ... does the 12R 22.5 require a slightly wider wheel? Or can you use a standard 22.5 wheel in an emergency?
I almost bought a complete set of Michelin 11R 24.5 tires and Alcoa wheel take offs from a wrecked highway truck tractor. Are the 11R 24.5 tires and wheels becoming harder to find nowadays?
Going to the Alcoa wheels would have required longer studs. Expensive. I think the revs per mile with both are nearly the same. Perhaps the 11R 24.5 tire is just slightly taller? Is this important?
In my case it did not matter. There was plenty of room in the wheel wells for chains. The take off tires were just a little bit too old and the price for the swap just a little bit too $high$. Good luck.
Sorry for choppy post.
Used to be 24.5 was easier to get. Now, that seems to have changed. I changed to 24.5 years ago because finding 22.5s at that time were sketchy.
I just replaced two steers this summer. Found difficulties finding wheels. Tires were not to bad to find.
Unless you're planning on changing out all your wheels, I would stay with 22.5. There's really not much benefit to changing to 24.5s.
HI;
A year ago I went with 315 80 22.5. I understand they are way more
tire than is needed, but I found they are easier to come by. I put used
on the rear and new on the front. The used tires were only $150 each
and less than two years old.
If you go with 24's you will also need wheels. Shop carefully.
Good luck, Merle.
I put 24.5's all the way around on Alcoas.
I like the slightly lower profile tire/rim ratio.
I looks a little unique. I like it. Your preference though.
(https://lh3.googleusercontent.com/P3NKHbpQXC79qI88rfXQWAB22nqfwpXSQiafnrpWF_eYdQqNCTTJUdPCd5-dH-WepDuAzcIfh8ssHD443ycvACZR4Y61XVhABLNw67i_qUkBeXwDP4LnpsIqJR4zET5H9-v55Vi2V9m-v12yqh26kNLNOmtVQmbeDwc2yMeeyf_HHbHuUAZHSkSfHD73tKydt9XAdGxCWxeZ8PUVpos7YZvf-cc2GKn9z1HnSpvvAI8d3QC1PryGr96cWbV9gGT_OyWFf-Zv1Vho38bEg8sIHUTC8QQ_qOFOYBSSKcXBAjIUegrUcOmGOk19augoYFUcj0qgfOZ9Psmi64gIpc1shpkFBuchP8FApWOPD1aoCzSRs5gmqpJJeUSezdqTzhSoo3tcHtKw6kkAx7wuivc56KdDJPyOVjtZT5YnIqve34v60nWcICMg1Siu9rMdPSY7Vl5TW5mTGY6-m9rONNneCgeWkrokCYptvvQplpj9stFKpsAqZoUjck1hUJRUZrQiXMA0yP1lZKpptkrkXAJDk2fHjLIKKJrVROOB6Bs5XlAQW17-EEJ19JAn6vsEptu14Mnsr2c4xNvpLqdASbEJCgwYYsIZsViB2waaGXwsC1Ff1OzjBcHonw=w736-h638-no)
I always wondered if the 24.5's rode harder since there is less tire to ride on than the 22.5's
--Geoff
A shorter tire sidewall may make a blowout easier to deal with . . .
However, if I was looking to change - I would look at what the current most popular tires are & choose from that list.
Tire sizes-275/80R-22.5 (Michelin low profile) and 295/75R-22.5 are about the same diameter at 517rpm. Then comes 11R-22.5 at 495rpm. Then the low profile 275/80R-24.5 and 285/75R-22.5-once again about the same diameter at 501rpm. Then next bigger is the 12R-22.5 and 315/80R-22.5 at 485rpm. The biggest diameter tire is the 11R-24.5 at 476rpm. You can see by the rpm differences, you can get a slower running engine at the same speed by going to a bigger diameter tire. I have 11R-24.5 tires that have big sidewalls. I use them mainly because that was what I ran on my trucks. And because my transit bus is lower. On my truck conversion, I also have 11R-24.5 to make the truck higher since I have 28" diameter fuel tanks-of which Kenworth would only put on trucks with 11R-24.5's. 24.5's are mainly used in North America and Canada (popular with the loggers). 22.5 rubber, which can be many sizes-235/80R, 255/70R, 265/75R, 275/65R, 275/80R, 295/75R, 295/80R, 315/80R, 385/65, 425/65, 445/65, 445/50, 455/55, 8R, 9R, 10R, 11R, 12R, etc. So when someone says they have 22.5 rubber-it means nothing without the actual size of the tire. Good Luck, TomC
I went with 11R 24.5 to go with a 4 stroke engine and a 740 trans. Now I have a 6 speed trans, using only 5 of them. So wishing I had 22.5 rubber now.
I have been considering changing my wheels/tyres to 24.5 diameter to raise the gearing on my bus. I just changed the steer tyres to 11R x 22.5. I have been pondering all the above considerations to weigh my choice so am interested in understanding too. My rears are currently 12R x 22.5
what did the engineers who designed it say ? :o ;D :o
Quote from: eagle19952 on January 23, 2017, 10:36:18 AM
what did the engineers who designed it say ? :o ;D :o
12R x 22.5 but what the hell do they know ;D
Quote from: luvrbus on January 23, 2017, 10:43:29 AM
12R x 22.5 but what the hell do they know ;D
hopefully what met the DOT spec for the loads ;D ??? ;D
The data tag for my bus -1980 - specifies a bunch of obsolete tires that are no longer available for any price, so that's a tad moot. 12R22.5 is what's on it, and the tire load weights for the rear are off the low end of the scale for those tires on the load-inflation chart. Even the fronts are barely on the chart. So I could use 11R-22.5 and save a ton of money and have higher RPM's as a result. Or I could buy 12R22.5's at a premium, or look for used 315-80 22.5 since they are real common around here on logging and dump trucks. Any MC-5 is going to be fine from a loading perspective with 11R-22.5, and a MC-7 might be, but I would weigh the front axle first. I don't think I will go with larger diameter tires with new wheels to save .05 mpg and lose hill climbing ability from the taller gearing. If someone dropped off a set of good tires on wheels that fit I would probably run them, though...
Brian
Stay with 22's Had to get 305/75/24.5's last year. $900 each!
Going from 12R-22.5 to 11R-24.5 is going from 486 to 476 revs per mile. So if you're turning 1800 at 65 with the 12R's, then with the 11R's you'd be turning 1763-not really worth it. Better to put in a B500 Allison with it's two overdrives of .74 and .64. Good Luck, TomC
We have no tags and our ride height is on the low side in our Eagle 10S. Because of this we run 24.5's
I'd love to run 22.5's but it just won't work with our setup.
I'd stay with 22.5's for the higher rpm's and slightly less weight as well as wider availability.
-Sean
I had no possible way to know when I posted this question how important and ironic it was going to be.
I am So very grateful for all of your input. I've got 12R22.5 on all Alcoa wheels now. My dad's best friend, same bus, same year, mostly same everything (when dad passed he was here the next day making sure I was solid). He and his wife were on I-95 last week just out side Charleston SC. He said the road felt "really rough" and then his RF tire blew (I was thinking he maybe had a goose egg, but that's not the point) The steering wheel jumped out of his hands, he had no brakes and ran into three rather large trees at 70 MPH...on curb side.
He's OK, mostly. His wife was reclined in her chair and lost her left leg below the knee in addition to a host of other injuries. She's still in SC until she can be moved home to VA.
After I spoke to him yesterday, I started thinking more about tires...and also adding impact bars to the front of the bus. I was working on tearing out the bedroom when I heard about the accident. I had the front skin off last year and realized there is really no protection whatsoever for the driver.
So, this to me anyway, has become a question of safety. An accident can happen to anyone, but as long as I'm doing this, I might as well set it up the safest possible way.
Is there a significant difference in load weight between 22 and 24? Having 22.5 now, it seems as most of you think I should keep them? I do remember mom nearly divorced dad (she was just PISSED) when he told her what the wheels cost. And when I'm finished with the re-do, she'll be getting ALL NEW tires.
The 12r x22.5 carries more weight most of the time more than a Alcoa wheel does, check the wheels for the weight limit they are not all created equal
I will do that. Important info...knowing my dad, the heaviest Alcoa had, but now I want to know.
Quote from: daddysgirl on January 24, 2017, 05:24:30 AM
I had no possible way to know when I posted this question how important and ironic it was going to be.
My dad's best friend, same bus, same year, mostly same everything (when dad passed he was here the next day making sure I was solid). He and his wife were on I-95 last week just out side Charleston SC. He said the road felt "really rough" and then his RF tire blew (I was thinking he maybe had a goose egg, but that's not the point) The steering wheel jumped out of his hands, he had no brakes and ran into three rather large trees at 70 MPH...on curb side.
He's OK, mostly. His wife was reclined in her chair and lost her left leg below the knee in addition to a host of other injuries.
That is a really really scary and sobering tale. Has got me thinking..... :(
Yes you are correct that in a head on collision the driver is always the first person there!
No the coaches don't have any major structural reinforcement for the driver's area.
And on top of that the reason for that is because of the design of the coaches in the first place!
Adding crash bars or whatever you can add to the front is not really going to make it any safer for you.
Because the fact that the driver sits so close to the front it doesn't matter if you add anything to the front all it's going to do is become something else coming in on the driver.
These buses are designed with safety factors considered and newer buses have the area the driver sits in re-enforced and in a crush away set up where as the driver, his seat and the immediate area around him get pushed back from the front area in an impact.
However it is not only impractical and highly dangerous to try and change the factory design in these areas. Most likely you would end up making things worse if you don't take it to an engineer who understands the original design as well as the physics of alterations.
The cost of the engineering and restructuring of the bus would be so astronomical it would simply be easier and cheaper to order a new shell that is already designed with the safety zone built in.
I admire your desire to make your bus safer, but please keep in mind the MILLIONS and MILLIONS of miles these buses travel with very few accidents and the reason that is the drivers take special care to avoid situations that will endanger their passengers and themselves.
As a side note a very close friend, and former driver of mine was driving a 2016 Prevost with less than 20,000 miles on it when he was hit head on on the drivers side by a Ford Expedition. It caused him to lose control of the bus and lay it on the passenger side in a ditch.
But he walked away with minor scrapes and bruises and a case of shock while the 23 year old mother of 3 that crossed the center line and hit him died on impact.
To this day it is unknown why she crossed the line, but the fact remains the same the shear mass of these buses gives us the drivers and the passengers the utmost advantage in most accidents.
FWIW
;D BK ;D
It got me thinking too...and I've been on a bus, one way or another (built three of them) since I was 12. I'm almost 46 now.
I have always known and understood the significance of the responsibility that is inherent when driving a bus. Safety has always been #1. Safety for everyone on the bus (my mom and kids, which is why the SS panel and bar are still on the passenger side stepwell)...Safety and responsibility for everyone else on the road, even the idiots...Being strong enough to know that if a dumbass in a VW is more worried about being in front of you when there is NOWHERE else you can put those 40'...that you will hit him before swerving and killing the people on the left...
But it took this to happen for me to have the first thought for my safety...as a driver. If something happens to me while traveling, no one is safe. That hit me like a ton of bricks yesterday. And I'm sorry for rambling. This has really shaken me, and if this accident causes one person to consider driver safety, something good will have come from it.
Quote from: B_K on January 24, 2017, 07:39:57 AM
Yes you are correct that in a head on collision the driver is always the first person there!
No the coaches don't have any major structural reinforcement for the driver's area.
And on top of that the reason for that is because of the design of the coaches in the first place!
Adding crash bars or whatever you can add to the front is not really going to make it any safer for you.
Because the fact that the driver sits so close to the front it doesn't matter if you add anything to the front all it's going to do is become something else coming in on the driver.
These buses are designed with safety factors considered and newer buses have the area the driver sits in re-enforced and in a crush away set up where as the driver, his seat and the immediate area around him get pushed back from the front area in an impact.
However it is not only impractical and highly dangerous to try and change the factory design in these areas. Most likely you would end up making things worse if you don't take it to an engineer who understands the original design as well as the physics of alterations.
The cost of the engineering and restructuring of the bus would be so astronomical it would simply be easier and cheaper to order a new shell that is already designed with the safety zone built in.
I admire your desire to make your bus safer, but please keep in mind the MILLIONS and MILLIONS of miles these buses travel with very few accidents and the reason that is the drivers take special care to avoid situations that will endanger their passengers and themselves.
As a side note a very close friend, and former driver of mine was driving a 2016 Prevost with less than 20,000 miles on it when he was hit head on on the drivers side by a Ford Expedition. It caused him to lose control of the bus and lay it on the passenger side in a ditch.
But he walked away with minor scrapes and bruises and a case of shock while the 23 year old mother of 3 that crossed the center line and hit him died on impact.
To this day it is unknown why she crossed the line, but the fact remains the same the shear mass of these buses gives us the drivers and the passengers the utmost advantage in most accidents.
FWIW
;D BK ;D
?
;D BK ;D
Posted the quote first...sorry about that.
I don't want you to think I am considering anything that would NOT be designed by a mechanical AND structural engineer. They run in my family...and my friends.
And you are, as usual, correct. These coaches are built and have traveled safely millions of miles. And 99.9% of the time, in a crash with even a large car...car's gone. I just wanted you to know I'm not advocating anything that would be dangerous. I have a friend (structural engineer who has a bus) who put 2 crash bars on an older coach. One where the trim piece is, just above the bumper, and one just under the wipers. I did the CAD work for him. They wrapped around the front, were attached to the frame, and had thick rubber blocks AND special shock absorbers.
Not to start an argument here, but keep in mind our "motor coaches" don't have an actual frame, like that of a school bus.
And I don't doubt that your friend has added crash bars to his bus.
But I do doubt that in a crash from 70 miles per hour into a solid object such as a tree, bridge column, or even a slowed or stopped semi truck his crash bars are going to do anything besides become part of the bus that is coming toward him very very fast.
In a collision with an object with less mass I can see the benefits of such bars, however I don't see the need for them except in a serious collision as described above.
I have been in the wrecker business all my life and have seen the results of many many crashes.
And having been in the wrecker business before, during and even still now I am always particularly interested in the damage/results of crashes I see or hear of.
I have another friend who was driving a late '80's MCI 102A3 and rear ended a semi truck in a traffic jam on I-40 an did receive a broken ankle and the other leg broken between the knee and ankle.
But he lived to tell about it and even got to drive the same coach again a little over a year later after he and the coach were both returned to duty with both receiving much needed reconstruction & rehabilitation.
I'm not saying if you want to build crash bars on your bus don't do it.
I'm simply saying I don't think it's necessary and it's time and money that could be spent in much more worthwhile ways.
;D BK ;D
I have too much respect for your opinion than to argue, and I clearly see where you're coming from...no worries.
And JFYI...the bars were designed for a head on with a noise wall at 65mph. Fortunately (for him) they tested in the world at 72mph into the back of a refrigerated truck carrying frozen Tyson chicken. He had to replace two of the little shocks.
BUT he designed them so they would specifically NOT become one more item that would wrap around him or decapitate him. He built them to prevent just that. I think because he was the engineer, he knew he could make himself safer. I'm not the engineer, but I'm certainly NOT thinking about roll bars on a 4x4 either.
But if I do anything like that (after I finish the engine, tranny, generator, water heater, plumbing electrical work, and then rebuild the interior etc...) I'll post it first.
But your valid point is well taken :)
When you consider that most states have a 12,000lb front axle, 20,000lb single rear axle, and 34,000lb rear tandem axle weight limit, you can go with most any truck tire you want-so long as it will support the weight of your coach. Most buses have 12R-22.5 which are naturally H rated (16 ply) at 7390lbs single, 6780lbs dual, turn 486rpm and weigh 140lbs. H rated 11R-24.5 is load rated at 7160lbs single, 6610lbs dual and weighs 131lbs. G rated 11R-24.5 is load rated at 6610lbs single and 6005lbs tandem and weighs 127lbs-which is also the the rating on the H rated 11R-22.5. G rated 11R-22.5 is 6175lbs single, 5840lbs tandem and weighs 118lbs. I could run G rated 11R-22.5, like most since my bus weighs 10,500lb front, 20,500lbs rear. But I use 11R-24.5 H rated (going to buy G rated next time) and run 90psi all around. I mention tire weight, since going from 8 12R-22.5 to 11R-22.5, you could go from a total of 1,120lbs of tire to 944lbs of tire-all of which is un-sprung weight and could mean for a slightly smoother ride. I know with big rig trucks, tire weight is important for more cargo carrying capability.
Since most bus conversions are not used for commercial passenger transportation, tire size and rating isn't legally important-only that the tires will carry the load. Good Luck, TomC
I appreciate the load information. I'm going to replace the tires, but the two I could see (before I got too cold) were G rated 12R-22.5 and they were tubeless and re-groove able, but I've never done that. I need to get her weighed when I'm finished because she's always been heavy as conversions go.
Thoughts on brand? I do know a bus shop that won't sell Michelin's for busses because the lead tech says they tend to dry rot and crack more easily.
Quote from: daddysgirl on January 24, 2017, 07:45:24 AM
It got me thinking too...and I've been on a bus, one way or another (built three of them) since I was 12. I'm almost 46 now.
I have always known and understood the significance of the responsibility that is inherent when driving a bus. Safety has always been #1. Safety for everyone on the bus (my mom and kids, which is why the SS panel and bar are still on the passenger side stepwell)...Safety and responsibility for everyone else on the road, even the idiots...Being strong enough to know that if a dumbass in a VW is more worried about being in front of you when there is NOWHERE else you can put those 40'...that you will hit him before swerving and killing the people on the left...
But it took this to happen for me to have the first thought for my safety...as a driver. If something happens to me while traveling, no one is safe. That hit me like a ton of bricks yesterday. And I'm sorry for rambling. This has really shaken me, and if this accident causes one person to consider driver safety, something good will have come from it.
I guess the only real comfort you can take is that a conventional RV is far more dangerous than even a 1960s MCI bus.
B-K I don't doubt that added mass when crashing with an immovable object helps, however - having bars helps against other minor annoyances such as Deer.
I hit a deer at 70 mphs in my Dodge Ram with bull bars. Result was no damage to the truck and a slight dent to one of the cars