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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: dj on February 28, 2018, 06:26:25 PM

Title: tire size
Post by: dj on February 28, 2018, 06:26:25 PM

Hey Guys just curious on what size tire your running...I have 11R24.5 and Im thinking going to 22.5 short rubber any thoughts?   
Thanks Doug

Title: Re: tire size
Post by: buswarrior on February 28, 2018, 06:40:39 PM

Revolutions per mile and load carrying capacity

Those are your two decisions.

Revolutions has a subtle effect on gearing, load carrying is a safety decision.

Buses used to be aimed at 495 revolutions per mile stock. The GM folks would seek out the tallest/lower rpm tireto squeak an extra couple mph outoftheir gear limited drivetrain. A heavy conversion might choose a higher number to squeak betterhill or headwind performance.

These are all subtleties, it won't change the world...

Happy coaching!
Buswarrior

Title: Re: tire size
Post by: DoubleEagle on February 28, 2018, 07:40:03 PM

11R24.5 tires will cost a little more to replace, but if you want to run Alcoa's, the cost of switching to 22.5 rims will negate that. 22.5 rims are more common now, but it used to be the other way around. If excise taxes or some other factor changes the economics, things might change again. I think the bigger rims look better.

Title: Re: tire size
Post by: luvrbus on February 28, 2018, 07:44:44 PM

What size does the chart say on the bus,Eagles were the only bus that ever ran 24.5 tires that I know of

Title: Re: tire size
Post by: eagle19952 on February 28, 2018, 08:19:29 PM

the guys (engineers) who designed the bus chose what's on it for good reasons.

Title: Re: tire size
Post by: TomC on March 01, 2018, 07:59:22 AM

I wouldn't change tire sizes. Both my bus and truck have 11R-24.5 rubber. As long as you can get 11R-24.5's, why change? You'll loose some top end speed.
11R-24.5 are 476rpm (revs per mile). 12R-22.5 are 485rpm. 11R-22.5 are 500rpm. 275/80R-22.4 or 295/75R-22.5 (most popular tire sizes now on big rigs) are 517rpm. Just multiply your rear end ratio by tire rpm to find out what engine speed you'll get at 60mph. Good Luck, TomC

Title: Re: tire size
Post by: dj on March 01, 2018, 05:12:08 PM

Thanks for the information guys ....the data placard says 22.5  so Im thinking about going to the smaller rubber so if I take it up to the mountains for skiing ill at least have room to throw tire chains on if i need to
thanks again for the info    Doug

Title: Re: tire size
Post by: Scott & Heather on March 02, 2018, 04:12:40 AM

So you’re willing to replace all your rims? I love my 24.5’s:

(https://uploads.tapatalk-cdn.com/20180302/7825d40e2de4c3e549c282085218184c.jpg)


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