Community Forums

LVRVLUVR · 03-23-2015, 09:29 AM

Quote:

Originally Posted by hackman

I notice several posters making comments regarding maximum tire pressure. It should be remembered that the maximum tire pressure allowed probably exceeds the maximum pressure rating on your wheel rims. In my case the Alcoa rims are rated for 120 psi cold.

I think there are few coaches requiring pressures this high.

that's a good point.... I still don't under stand Fleetwood putting the little 255 tire on the 8.25 aluminum rim either...

aluminum wheels bend easier , and with low tire pressure ... even easier...

Ray,IN · 03-23-2015, 05:48 PM

Quote:

Originally Posted by Waiter21

Ray, Yes, I understand the tables are for cold temperatures.

In your opinion, what is the maximum tire pressure?

The maximum air pressure a truck tire will withstand is around 1,800 psi. That is beyond any pressure a truck would ever use of course. When a tire is inflated to 120 psi, it is not unusual to see a TPM display operating pressures around 130-145psi. Tires are built to withstand this heat-related pressure increase, as are the rims. That is the reason for the specific marking of "cold inflation pressure".
You will note the tire sidewall states 120 psi; this is the minimum air pressure to safely carry the maximum poundage stated on the sidewall.

mvpmich · 03-23-2015, 06:22 PM

Add 5 lbs to min pressures (as long as it doesn't exceed max) and you will still have soft ride and can accommodate some extra weight in the MH just in case.

LVRVLUVR · 03-24-2015, 03:33 AM

right now after a 500 mile trip with the correct advised air pressure...running the right pressure for the weight is a major ride enhancement

Tireman9 · 04-19-2015, 02:40 PM

I see a lot of discussion here with axle weights and the assumption that the axle loads are evenly split side to side.

Well I don't want to rain on your parade but here are some real numbers from a Class-A owner.

RF - 4650#
LF - 4950#
RR - 9050#
LR - 7800#

You can see that he will end up with low inflation on some tires if he "assumes" a 50/50 side to side split.

These numbers are not all that unusual as 1,000# side to side variation is seen frequently by RVSEF.

jadatis · 04-20-2015, 05:45 AM

Also mind the crossed weight differences in the weights Tireman9 gave.
Front Left more heavy and rear right more heavy.
This is more rule then exeption when weighing motorhomes, but also tandem or tripple axle trailers or 5th wheelers.

But is rear realy 1250 lbs weight difference?? or is it a miswriting?
Front "only " 300 lbs weightdifference.
R/L weightdivision
Front R 48.4%/L 51.6%
Rear R 53.7%/L 46.3%

Not saying its not possible, but expected it to be about the same weightdivision %.

Crasher · 04-20-2015, 10:15 AM

Quote:

Originally Posted by Tireman9

I see a lot of discussion here with axle weights and the assumption that the axle loads are evenly split side to side.

Well I don't want to rain on your parade but here are some real numbers from a Class-A owner.

RF - 4650#
LF - 4950#
RR - 9050#
LR - 7800#

You can see that he will end up with low inflation on some tires if he "assumes" a 50/50 side to side split.

These numbers are not all that unusual as 1,000# side to side variation is seen frequently by RVSEF.

If this is an air suspension coach, the imbalance can easily be corrected by adjusting the ride height. I had a similar difference on our coach and found one adjuster to be 5/8" off. After the correction, the front was within 100# and the rear within 400#.

Tireman9 · 04-20-2015, 01:23 PM

I was not given the reason for the imbalance. Air bags, broken spring, bent frame etc etc.
Just pointing out that only a small % of RVs are 49/51 or closer