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Topic: Firestone FS561 tires (Read 1973 times) previous topic - next topic

Re: Firestone FS561 tires

Reply #20 –
John,

Wonder if the heat he mentions is because of a different tread pattern or tread depth? Especially if the H is at 120 psi, the tire should flex less. I do know that the "green" tires all the companies seem to be making now, generate less heat and get better mileage. Perhaps the increased amount of steel there is to flex in some tires, the warmer they run at equal pressure.

Pierce

Re: Firestone FS561 tires

Reply #21 –
Happened on this Bridgestone pressure/load chart and since the size applies to our Foretravels, thought I would quote it. Check the stationary pressures recommendations. Translates directly into off season storage for our coaches. I wonder if low tire pressure in storage might translate into failures while underway? Looks like Bridgestone would like customers to add 30 psi to tires if the they are at max load during storage. They also note the maximum cold rim pressure. Wonder if taking the load off the tires during storage might keep the tires and Bridgestone happy?

Relationship of Speed and Pressure to Load
For Metric & Wide Base Radials [for example, 295/75R22.5]
 
MPH      % Load Change  Infl. Pressure Change
71-75*          -12                +5psi
66-70*          -4%              +5psi
51-65            None            No Increase
41-50            +7%              No Increase
31-40            +9%              No Increase
21-30            +12%          +10psi
11-20            +17%          +15psi
6-10              +25%          +20psi
1-5                +45%          +20psi
Creep (2)      +75%          +30psi
Stationary    +105%        +30psi

For Conventional Radials [for example, 11R22.5]
 
MPH    % Load Change    Infl. Pressure Change
71-75*            -12%          +5psi
66-70*            -4%            +5psi
51-65            None              No Increase
41-50              +9%            No Increase
31-40              +16%          No Increase
21-30              +24%          +10psi
11-20              +32%          +15psi
6-10 (1)          +60%          +30psi
1-5 (1)            +85%          +30psi
Creep (1, 2)    +75%          +30psi
Stationary (1) +185%        +40psi

* No change necessary for Bridgestone tires rated for use at 75 mph


1) Apply these increases to Dual Loads and Inflation Pressures.

2) Creep-Motion for not over 200 feet in 30-minute period.

Note 1: The inflation pressures shown in the referenced table are minimum cold pressures for the various loads listed. Higher pressures should be used as follows:

A. When required by the above speed/load travel.

B. When higher pressures are desirable to obtain improved operating performance. For speed above 20mph, the combined increases of A and B should not exceed 20psi above the inflation specified for the maximum load of the time. The maximum load and inflation capacity of the rim must not be exceeded.

Pierce