| Author |
Message |
phil8tx (63.108.55.17)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 18, 2004 - 6:02 am: | |
I am running R80/315/22.4 tires reccommended to carry 120psi but my compressor only pumps in about 100. Am I doing any harm running at 1oo psi? |
Bill Butler (198.81.26.45)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 18, 2004 - 9:04 am: | |
I have the same thing. I tape the pressure relief
valve and hold the on/off switch on until I get
110 pds. which is what I run on a 4905.
To do this with a compressor may not be very smart unless you know your tank will hold the pressure. It work for me. |
James Maxwell (Jmaxwell) (66.81.54.208)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 18, 2004 - 10:07 am: | |
I doubt that u are doing any damage at 100 psi, although it is often stated that inflation should be kept within a 10% range of rating. I have yet to meet the real expert on tires and my opinion is that the cause of failures is more a matter of guess than fact. Certainly, Firestone or Michelin, or any other maker is not going to admit to putting out a faulty product and will seek every opportunity to blame some intransigent factor for premature failures. While some argue that lower pressures cause more flexing and thus higher heat, I could also argue that it is a thermodynamic fact that higher pressures create higher heat. Considering that my tires are loaded well below their limits, I generally run them 10-15% below their max inflation rating for the smoother ride. Manufacturers do publish load/inflation charts, but they are not readily available if u ask to see them at your local Les Schwabb dealer. |
RJ Long (Rjlong) (66.229.97.200)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 18, 2004 - 10:53 am: | |
Phil -
Have you weighed your coach? If not, do so. Run it across some truck scales, and obtain the weight being carried by each axle.
Divide each axle's weight by the number of tires on that axle, which will give you the average weight carried by each tire. Add a couple hundred lbs. to this average as a fudge factor, then go to the inflation/load charts on the website for your tire brand. Use the chart to determine the correct tire pressure for the tires on each axle. You may find it's quite different, front to rear.
This is what five different tire manufacturer's reps (Michelin, Goodyear, Bridgestone, Toyo and Kuhmo) have told me is the correct way to determine the proper inflation for a particular vehicle. If all the manufacturer's are saying the same thing, well, draw your own conclusions.
Are you doing any harm running at only 100 psi? You won't know until you weigh your coach.
HTH,
RJ
PD4106-2784
Fresno CA |
Gary Carter (68.25.65.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 18, 2004 - 12:43 pm: | |
Just a note added to RJs and that is the figures on the sidewall are maximums and not recommended. Until you weight your coach this thread is of no value. |
DonTX/KS (66.82.9.48)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 18, 2004 - 7:44 pm: | |
This has been a common misconception for years, and comes up often. As said, if you read the sidewall carefully, it only says that pressure AT MAXIMUM LOAD for the tire. As well said by RJ, weigh it and inflate accordingly. Overinflation kills tires too you know. |
BrianMCI96A3 (65.160.209.132)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 19, 2004 - 12:30 am: | |
Yep, it's the load they carry...
We have a yard tug with duals that has heavy duty truck tires, high milers, a bunch of plys, but because the tug has no suspension and really isn't all that heavy, we maintain the tire at no more than 10 to 20 psi in them, and the they still have good tread on them with no unusual wear.
Brian |
Phil Dumpster (24.16.243.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 19, 2004 - 11:34 pm: | |
If your shop air source cannot get up to 120 PSI, you can always tap into your brake system. |
Stephen Fessenden (Sffess) (65.154.177.46)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 22, 2004 - 9:21 pm: | |
I adjust the pressure regulator up to around 130 PSI when inflating bus tires. There should be two screws under the regulator cover, one to raise only maximum pressure and the other to raise cut on and cut off pressure together. I adjust the screw that adjusts both cut on and cut off pressure. Count the turns and you know where to reset it after you are through inflating. |