Author Topic: Tire question for Bus Warrior  (Read 5749 times)

Offline chessie4905

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Re: Tire question for Bus Warrior
« Reply #15 on: December 15, 2019, 06:47:11 AM »
Make sure you don't  run the pressure in the duals that they have sidewall rub over rough or uneven surfaces on road.
GMC h8h 649#028 (4905)
Pennsylvania-central

Offline luvrbus

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Re: Tire question for Bus Warrior
« Reply #16 on: December 15, 2019, 07:53:53 AM »
The tire deal is a personal preface,all owners are different and it's their money so they do what works best for them regardless of what internet experts think or do  ;D
Life is short drink the good wine first

Offline DoubleEagle

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Re: Tire question for Bus Warrior
« Reply #17 on: December 15, 2019, 10:28:24 AM »
I think monitoring tire temperature might be the ultimate way to find the ideal tire pressure. The question is, what is the ideal temperature range for tire safety and life? From what I can find on RV and truck forums, up to 50 degrees above air temperature is normal, the air pressure monitors that record temperature have alarm points in the 150's, and one source said that tire failure can occur at 180-200 degrees F. Looks like tires should not be hotter than a safe two-stroke temperature. For each bus there should be an optimum temperature/pressure level that results in good tire life and a less harsh ride. I rode on a current Greyhound MCI last spring, and the fronts were set at 130 psi. You could feel and hear every crack and expansion strip.  :o
Walter
Dayton, Ohio
1975 Silvereagle Model 05, 8V71, 4 speed Spicer
1982 Eagle Model 10, 6V92, 5 speed Spicer
1984 Eagle Model 10, 6V92 w/Jacobs, Allison HT740
1994 Eagle Model 15-45, Series 60 w/Jacobs, HT746

Offline belfert

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Re: Tire question for Bus Warrior
« Reply #18 on: December 15, 2019, 11:26:10 AM »
I want to run a tire pressure that results in the best comfort for my tire weights that doesn't result in premature tire failure.  Tire pressure may have had nothing to do with my sidewall blowout, but I'll never really know.  I know I didn't hit a curb or something like that as it was the inside dual.
Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN

Offline Jim Blackwood

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Re: Tire question for Bus Warrior
« Reply #19 on: December 15, 2019, 04:20:10 PM »
I've heard that it is common to run about 10% over the chart pressure but have no way to confirm that. However it would seem that would aid in blowout protection without unnecessary harshness.

Jim
I saw it on the Internet. It MUST be true...

Offline Boomer

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Re: Tire question for Bus Warrior
« Reply #20 on: December 15, 2019, 07:00:06 PM »
At the Prevost factory back near where they assemble the axle units there is a guy that mounts tires on the wheels all day every day.  When we were buying new buses we specified and underlined on every order what pressure we wanted.  No matter, every tire on every coach came out with a different pressure, quite often with huge spreads in between.  Oh well...
'81 Eagle 15/45, NO MORE
'47 GM PD3751-438, NO MORE
'65 Crown Atomic, NO MORE
'48 Kenworth W-1 highway coach, NO MORE
'93 Vogue IV, NO MORE
1964 PD4106-2846
Vancouver, WA USA

Offline richard5933

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Re: Tire question for Bus Warrior
« Reply #21 on: December 16, 2019, 02:49:14 AM »
...I have nothing nice to say about FMCA and anything technical... 
Happy coaching!
Buswarrior

The guy I was talking about isn't working for FMCA. Roger is a tire engineer. Here's his site with lots of good information, based on data he's collected over the decades he's done this.  http://www.rvtiresafety.net/

I've heard that it is common to run about 10% over the chart pressure but have no way to confirm that. However it would seem that would aid in blowout protection without unnecessary harshness.

Jim

That's what Roger from from rvtiresafety.net recommends.
Richard
1974 GMC P8M4108a-125 Custom Coach "Land Cruiser" (Sold)
1964 GM PD4106-2412 (Former Bus)
1994 Airstream Excella 25-ft w/ 1999 Suburban 2500
Located in beautiful Wisconsin

Offline Bob & Tracey

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Re: Tire question for Bus Warrior
« Reply #22 on: December 16, 2019, 02:37:57 PM »
Bus Warrior,
I have never tried running 70lb. The ride is still a bit harsh at 90Lb but it it really sucked at 120lb...
Bob & Tracey Rice   

1956 GMC PD4104-1611

Offline dtcerrato

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Re: Tire question for Bus Warrior
« Reply #23 on: December 16, 2019, 04:48:34 PM »
Bob 70 psi is low - even for a back dual. 90 sounds good for the front. 120 psi is way too much psi for your conversion. Remember. When reading a specific tire pressure load chart to see if the column your reading the psi from is for a single or dual tire set up. We run about 5 psi heavier than the actual psi called for on a particular load. That gives some safety net not to be running "soft" (they run hotter that way).
Dan & Sandy
North Central Florida
PD4104-129 since 1979
Toads: 2009 Jeep GC Limited 4X4 5.7L Hemi
             2008 GMC Envoy SLT 4x4 4.2L IL Vortec

Offline lostagain

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Re: Tire question for Bus Warrior
« Reply #24 on: December 16, 2019, 06:04:27 PM »
I had BF Goodrich tires on my 5C for several years. I ran them at 70 psi. That was the sweet spot for them. Now my no name Chinese tires run best at 80 psi. Same bus, same weight.

JC
JC
Blackie AB
1977 MC5C, 6V92/HT740 (sold)
2007 Country Coach Magna, Cummins ISX

Offline Dave5Cs

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Re: Tire question for Bus Warrior
« Reply #25 on: December 16, 2019, 06:14:23 PM »
My Toyo's run great at 85 up front and 80 in the back and the book says 90 all the way around. :)
"Perfect Frequency"1979 MCI MC5Cs 6V-71,644MT Allison.
2001 Jeep Cherokee Sport 60th Anniversary edition.
1998 Jeep TJ ,(Gone)
 Somewhere in the USA fulltiming.

Offline dtcerrato

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Re: Tire question for Bus Warrior
« Reply #26 on: December 16, 2019, 07:21:57 PM »
I assume with the transition from nylon bias to steel belt radials - running a tire on the soft side for comfort shouldn't be an overheat problem as much as it used to be. Coupled with the change in tire pressure, replacing all the shocks on the bus made the two AK road trips like night & day
Dan & Sandy
North Central Florida
PD4104-129 since 1979
Toads: 2009 Jeep GC Limited 4X4 5.7L Hemi
             2008 GMC Envoy SLT 4x4 4.2L IL Vortec

Offline chessie4905

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Re: Tire question for Bus Warrior
« Reply #27 on: December 17, 2019, 03:36:14 AM »
Ahhhhhh. Good old nylon cord tires. Flat spot when parked. Took ten miles to get them round again till parked.
GMC h8h 649#028 (4905)
Pennsylvania-central

Offline luvrbus

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Re: Tire question for Bus Warrior
« Reply #28 on: December 17, 2019, 06:01:56 AM »
Ahhhhhh. Good old nylon cord tires. Flat spot when parked. Took ten miles to get them round again till parked.


It about the same when the tires of today get 5 years old they ride like a rock and pickup the road noise,as far the heat a tire has to dissipate the heat it generates (equalibiruim) some do a better job than others in the radial tires 
Life is short drink the good wine first

Offline chessie4905

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Re: Tire question for Bus Warrior
« Reply #29 on: December 17, 2019, 07:59:42 AM »
Plus the hardening of the strut bushings as they age. Few ever replace them. Several years ago, we worked on a Ford F350 4x4. Rode like a cement mixer over bumps. It was brutal. Did other work, but replaced all the rubber bushings in the front end. Wow! Couldn't believe the improvement in ride quality. It was incredible.
GMC h8h 649#028 (4905)
Pennsylvania-central

 

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