Date: Fri, 21 Aug 2015 12:31:00 -0700
Reply-To: Mark Hersh <cmwolfsburg@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mark Hersh <cmwolfsburg@GMAIL.COM>
Subject: Re: Proper Tire valve stems?
In-Reply-To: <BAY405-EAS1432A76541BDDE4B0B470EBA0660@phx.gbl>
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I ran across this paper on the interweb
http://www.dawsengineering.com/linked_files/tirepressureatreducedloads.pdf
that says that a conservative estimate of load supported by
less-than-maximum inflation is a simple proportion. A more accurate
estimate would take into account the stiffness of the sidewall. More
conservative is fine with me.
Example, with the Nokian eNTYREs I just put on Monty:
First, I reduced the max load by 10% per some official body's guideline
when running an XL tire on a van/truck. So the 1764 lbs max (100T rating)
on the tire is 1587 at 51 psi.
The Gross Vehicle Weight Rating on the plate on Monty's door jamb is front,
2646 lbs, rear 2866 lbs, so I need 1323 lbs supported per tire on the front
and 1433 on each rear tire.
Those particular weights could be supported by 46 psi in the rear and 42 in
the front. So I'm thinking that's the MAX I will ever have to inflate
these tires.
I did not get much help from Nokian when I asked for a load-inflation
table. They asked me what psi's I was interested in, so I told them 36 to
51 and they have not yet responded.
Mark
On Thu, Aug 20, 2015 at 3:36 PM, Dennis Haynes <d23haynes57@hotmail.com>
wrote:
> Proper valve stem length is really a function of wheel covers or the lack
> of. If not using any wheel covers you normally want the shortest stems
> available especially for driving in snow or any off road adventure. The
> longer the stem the easier it is to break off. With covers you want the
> valve long enough so it can be serviced with the wheel cover in place.
>
> In the real truck world metal valves are usually used.
> The 65 psi is the max inflation pressure for the tire. You want to follow
> the door jamb specifications or get the load-inflation table for the tire
> you are using and use the maximum axle weights to determine proper
> pressures.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of T Collins
> Sent: Thursday, August 20, 2015 12:37 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Proper Tire valve stems?
>
> Hello List,
>
> I'm about to get all new tires mounted. I know these are LT tires and are
> rated @65psi. When replacing the valve stems is there any that "NEED" to be
> used because of the higher PSI.
>
> I dont want a leaky tire with these. I have the 14" steel wheels. Also I
> think the current stems are too short. Should they be 2" valve stems?
>
> What says you?
>
> Thanks,
> T.
>
--
86 Campmobile Six-Seater "Monty"
Black dogs are euthanized at a greater rate than other-colored dogs,
regardless of temperament. Learn about Black Dog Syndrome at
http://www.blackpearldogs.com/ Learn about black dogs in a Vanagon at
http://www.pbase.com/mhersh/image/108220533
