Tire fitment question

[Don Bradner]

Am I correct in assuming your front axle GAWR is less than 14,000 lbs, being a
non-widebody?

On 3/15/2013 at 9:23 AM Joe Garner wrote:

>Just checked mine.
>
>
>Firestone aluminum, 8.25 x 22.5, Max load 7000# @ 120psi.
>
>'87 PT40
>
>/Joe
>
>
>
>
>On Fri, Mar 15, 2013 at 5:49 AM, Michael Bulriss <mbulriss@...>
>wrote:
>
>> **
>>
>>
>> To add to this discussion, my aluminum wheels are stamped 7250 lbs at 120
>> psi. The 12R22.5 tires are labeled 7390 lbs at 120 psi for single wheel
>> use.
>>
>> More importantly the tire charts specify that the duals have a minimum
>> 13.2" spacing with the 12R and minimum of 13.8" with 315s. Measuring the
>> current rear spacing on the 8.25 wheels with 12R tires shows them barely
>at
>> the 13.2 minimum spacing, so I am concerned how people are mounting 315s.
>>
>> FWIW, one Michelin chart shows the 315 tire max load at 8000 lbs on 8.25
>> wheels versus the 9090 with 9.0 rims. Seemed like a dramatic change.
>>
>> Decisions, decisions. Having a head time deciding next step since I am
>> just updating the steers currently and moving those tires to the tag. I
>had
>> thought the slightly wider 315 would make a difference on the steers,
>> because even when i changed from 7.5 to 8.25 wheels on the 83PT and
>stayed
>> with 11R tires, it made a big improvement in driving feel by widening the
>> tire cross section out. FWIW.
>>
>> Mike Bulriss
>> 1991 WB40 "Texas Minivan"
>> San Antonio, TX
>>
>>
>> Sent from my iPhone
>>
>> On Mar 15, 2013, at 12:43 AM, "Don Bradner"
>> wrote:
>>
>>
>>
>> Is that your Wide Body with that 7000 lb rating?
>>
>> Clearly, Alcoa has made a lot of different rims at 8.25 inches over the
>> years. I wish I had a WB sitting in front of me so I could look, but I do
>> know that mine were not below the '90's 14,600 front axle rating, which a
>> 7,000 lb would have been. In the current Alcoa book they list several
>> different 8.25 22.5-inch wheels, with ratings as high as 8050 lbs, but
>none
>> lower than 7300.
>>
>> At 110PSI, the 12R is rated for 6870 lbs in a single tire configuration,
>> which would be underinflated for any of the 90s wide bodies. They all
>> needed a full 120PSI to carry the full weight. I'm surprised an 88WB
>> wouldn't weigh that much.
>>
>> The ride difference between a 12R at 120 and a 315 at 100 IS noticeable.
>>
>> The rubbing when suspension-dumped with steering turned had nothing to do
>> with pressure. It is a phenomenon on most, if not all, of the wide-bodies
>> at any pressure.
>>
>> On 3/15/2013 at 5:23 AM tulipvendor50 wrote:
>>
>> >Don stated:
>> >"Alcoa documents list 8.25-inch rims variously as 7400 lbs"
>> >
>> >Bill:
>> >There is a coach right next to me with 8.25 inch rims and it clearly
>> >states "7000lbs"
>> >
>> >Don stated:
>> >"As far as the fenders I had the older rubber ones, and the tires would
>> >hit when dumped-while-turned even with 12R - the extra half-inch of
>tread
>> >on the 315 made no difference. I did NOT put 315s on the drivers because
>> >of the potential rubbing issues. Those that have done so (Shane comes to
>> >mind) run their drivers at higher pressure than needed for the load,
>which
>> >negates the ride improvement. "
>> >
>> >Bill:
>> >I run my tires at 110lbs pressure and have had no problem with the
>> >rubbing. I doubt very much if one could really feel the difference in
>> >ride with the higher or lower pressure.
>> >
>> >
>> >
>> >
>> >------------------------------------
>> >
>> >Yahoo! Groups Links
>> >
>> >
>> >
>>
>>
>>