| Author |
Message |
David Anderson (66.90.198.156)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 21, 2003 - 10:51 pm: | |
I have 24.5" Dunlop radials on the front of my Eagle 10. Book pressure calls for 105psi so that is where I put them. The ride seems rough. Those tires slap every bridge expansion joint like a hammer. I just installed new Gabriel Air ride shocks on the coach, so that shouldn't be a problem.
My question is can I lower the pressure until the ride gets more comfortable? I tried to get to Dunlop's website, but nothing comes up.
What do most of you guys do? I'm looking for some experience here. Thanks in advance.
David Anderson |
jmaxwell (66.42.92.12)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 21, 2003 - 11:30 pm: | |
10% under on the tire sidewall spec. |
Jayjay (198.81.26.108)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 22, 2003 - 12:56 am: | |
105 psi is for the max rated load of the tire. Probably about 5065 lbs. if it's H rated. I've been using 95 psi for several years now with no adverse wear characteristics. Be sure and check the temperature after a long run on a hot day to see if they are a little too hot. This is a sign of overload, and is the most common cause of tire failure. You will have to know the weight of your coach... front, rear, both axles to be sure you don't overload them. ...JJ |
RJ Long (Rjlong) (24.127.74.29)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 22, 2003 - 2:00 am: | |
At the FMCA party in Pomona three years ago, Michelin put on one of the various seminars. Their recommendation for finding the correct tire pressure is as follows:
~ Run your coach across a set of public scales, loaded and ready for the road, with full tanks, cupboards, fridge, closets, toolbox, etc. Be sure to obtain weights for each axle.
~ Divide the weight of each axle by the number of tires on that axle. Add 100 - 150 lbs to the results as a fudge factor for additional "stuff", thereby giving you the average weight on each tire.
~ Go to the tire manufacturer's published load charts for the particular tire on your vehicle. This may or may not be on their website, or you might have to obtain a hard copy from a local dealer.
~ Using the chart for your particular tire, find the column that most closely matches the weight determined during the above exercise. Read the recommended psi, and adjust accordingly, but NOT LESS than the lowest recommended pressure listed, nor MORE than the maximum indicated on the sidewall. Be sure to note whether it's a single or dual application - the pressures are different.
That's the basics of Michelin's recommendation. Obviously, your mileage may vary. . . check with your own tire brand's dealer for their advice.
On my own coach, the last time I ran it across the scales, it weighed 20,633 lbs. Based on Sumitomo's load charts (which is the tire brand that's on the coach at the moment), I'm running 75 psi front and 70 psi duals.
HTH,
RJ
PD4106-2784
Fresno CA |
David Anderson (66.90.196.121)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 22, 2003 - 10:40 pm: | |
The load range is H, max load is 3250 (single) at 120 psi. Whew, at that pressure, they would really be bumpy.
I don't know what my axle weights are, but I had the bus weigh in once at 30400lbs. I wasn't finished with it yet, and still am not. I'll get it weighed again after all is done.
I don't have access to individual scales, however, so weighing the axle loads may be difficult unless I find some.
David Anderson |
jmaxwell (66.42.92.5)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 23, 2003 - 12:48 am: | |
If ure tires are rated at 3250 as u indicate (seems at least 2000 # under-rate) then clearly you have more than Max load for your tires and u need all the pressure u can get and then some. I would re-check the weight ratings on the sidewalls again; I think it should be more in the range of 6-7000 each. |
Gary Carter (216.17.8.77)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 28, 2003 - 2:23 pm: | |
The answer is very simple. None of us knows. YOU HAVE TO WEIGH THE AXLES before tire pressure can be determined. There is simply no other way to do it. |
RJ Long (Rjlong) (24.127.74.29)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 28, 2003 - 2:47 pm: | |
David -
Gary's right, you've GOT to weigh the axles before you can determine the correct air pressure.
Somewhere in your area you should be able to find a set of truck scales to run your bus across. Could be at a truck stop, a grainery, moving & storage company (Bekins), etc. May cost you five or six bucks, but it will help you solve this problem correctly.
If you can attend an FMCA party, frequently a company called "A-Weigh-We-Go" will be there, and there's usually a line for people wanting to have their rig's weighed. They weigh each tire patch area to give you an accurate assessment.
But in the interim, a truck scale will do the trick just about as well. . .
Then be sure to use the method recommended by Michelin outlined above, once you have your weights.
HTH
RJ
PD4106-2784
Fresno CA |
Abajaba (12.217.206.141)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 28, 2003 - 4:18 pm: | |
An alternative to taking the vehicle someplace that
charges $'s to weigh the vehicle is to go to a DOT
scale along the highway when they are closed.
Normally this is late at night and most weekends
here in Iowa. Then when no one is there, you can
weigh your bus for free if they leave the electronic
scale turned on. The readouts on the scales here in
Iowa are big enough to see from twenty feet away.
Abajaba |
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