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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: JohnEd on September 10, 2009, 01:48:18 PM

Title: Narrow tire better?
Post by: JohnEd on September 10, 2009, 01:48:18 PM
I have decided to keep the old but renewed 74 Winnie.  After, and if, the Pre happens, Winnie will become a private guest cottage at home and may be put on a separate piece of property.  For sure, for sure I could never get anything for her even though I have been told that a strong 440 with a 727 and a Spicer 70HD with posi would be worth $3k.  I don't know where that would be and tend to doubt it.

So here is the question:  That old girl has a new set of Bridgestone 19.5X8 tires installed.  Winnebago had lots of tires sizes to choose from.  I remember that almost all the med delivery trucks had those old skinny tires.  I was told that they ram easier and got better MPG and also lasted much longer than the wider tires.  Is that true?  Also was told that those tires were harder on the streets than the wider, newer, designs.

I see where some Knuts have upgraded their Alu rims to 9" from 8.5" so they can run wider 315 tires and go from 11 to 12 inch wide tires.  What are the advantages of 12 inches vs 11 inches and i am still talking tire here?

Thanks,

John
Title: Re: Narrow tire better?
Post by: TomC on September 10, 2009, 02:35:48 PM
If you figure out the weight per inch of tire, you'll find that your tires are probably not excerting the same amount of force as a truck or bus tire.  When you consider that a 315 width tire can be rated at 10,000lb, that's over 800lb per inch (and tires are measured outside to outside at the widest point-not the tread width).  So your 8" tires are way under that.  At 550lb/sq"-which is approved in all states-that translates to 4400lb per tire or 8800lb for the front end-which I think is way over what it is rated at.  Isn't it just a 6,000lb front end with a 10,000lb rear?  Good Luck,TomC
Title: Re: Narrow tire better?
Post by: luvrbus on September 10, 2009, 03:05:27 PM
John, it is all about ride for me I rode in a Eagle with 315 tires and yes it does improve the ride, the cost that part I don't think it is worth the price now but it is too late for me now.
I tried TomC's advice on the 70# and the next time you see Doyle ask him what my tires look like now.
So being I needed new tires I went for the 315 size it may come back to bite me but I am going that way.
My tire guy Lewis Brothers in Baker City OR told me today tire manufactures love it when folks run the 315 or 12 r tires at 70# no matter what weight cuts the life of the tire by 25% 70# and a China made tire gauge will cost you 



good luck
Title: Re: Narrow tire better?
Post by: uncle ned on September 10, 2009, 03:51:49 PM


I have a old cruise air with the 440 also.I Keep every thing, love my junk.

The 440 in the motor homes have the steel crank. If you want to sell it look for a person restoring a dodge hot rod.

They want the crank to build big horsepower engines.

uncle ned
Title: Re: Narrow tire better?
Post by: JohnEd on September 10, 2009, 04:49:01 PM
Tom,

It does weigh 6 and 10 K or maybe 5 and 10.  But you have it pegged.  Chassis is the Dodge RM400.

Thanks,

Clifford,

I got nothing to compare the ride.  It seems to be smooth enuf.

Unk,

Thanks for the info on that.  It is a great engine...more power than I need and how often have I ever said that????

I once got 9.5 out of her but I think that was Nebraska or so.  Used to do 8.5 without a problem.  Best I got years ago, most recent data, was 7.5 and that still turns heads in the S$S arena.  My last set of Lee tires may have been why it dropped but that is just grouping for an explanation.  I still like the old girl but I have a few problems yet to work out.

John