Question about tires..smell? Temp?

[cbigham]

Hi all,
Have a question about tires..Tires are hot at 80, 82 psi returning from cold mountain trip thru local desert, traffic and home. Rear tires noticably hotter than fronts and had a smell like hot rubber.
Posted are the weights on the axels for my 23u thor. I notice I'm about 700lbs below the limit of the rear axle. Usually that axle is loaded about 600 lbs lighter. No smell, not so hot.

Is there a danger? Factory michelin tires, 2016 date. Don't recall smelling this. Tires not painful hot but hot. Touched the rims, axle shafts..not the source of heat. It's tire flex. This is the most I've loaded this. E450 chassis, 2017 model 14,000 gvwr. Usually carry a 300 lbs motorcycle on back never a worry. This time a 470 lbs bike and about another 50lbs lbs for the more stout rack tying into frame.

Any thoughts?


Thanks

Cb

[CA_Traveler]

Desert Captain wrote:
"Weight is based on fully loaded, full fuel, water and propane."

Not sure what you mean... Weight is weight regardless of how you get there. Our E-350 with a GVWR of 11,500# can be anywhere from 10,000 to 11,500 depending on how I am loaded and/or towing. Weigh the coach loaded as you normally travel and then set your psi based upon the tire manufacturers load/inflation table. The weights shown on your door jamb are rarely accurate in the real world.

Depending on your tires load rating {D, E, F whatever} your tires may be quite capable of handling their actual loads and still be well under the max psi found on the sidewalls. Max Psi and door jamb numbers might maybe be accurate occasionally but never assume them to be correct without knowing the load each tire is actually carrying.

Just sayin...

:C

OK, agree Just sayin... - tryin to say that is. RV fully loaded, full water, fuel, propane (and passengers) and use that axle weight for the load inflation tables.

If you know your actual weight for a given trip and choose to adjust your tire psi for that trip then ...

[CA_Traveler]

DrewE wrote:
I wouldn't be worried. If one tire were noticeably hotter than the others it would be good to give that one some scrutiny as it may be low or delaminating internally or something; but tires generally getting quite warm in use is normal. (I'm assuming the cold inflation pressures are correct for the weight they're carrying; pressures when they're hot will of course be higher per the ideal gas law.)

I highly suspect the smell comes from something other than the tires.

X2

Tire temp and hence psi is also dependent on road condition and the sun can be a significant factor.

[Desert_Captain]

"Weight is based on fully loaded, full fuel, water and propane."

Not sure what you mean... Weight is weight regardless of how you get there. Our E-350 with a GVWR of 11,500# can be anywhere from 10,000 to 11,500 depending on how I am loaded and/or towing. Weigh the coach loaded as you normally travel and then set your psi based upon the tire manufacturers load/inflation table. The weights shown on your door jamb are rarely accurate in the real world.

Depending on your tires load rating {D, E, F whatever} your tires may be quite capable of handling their actual loads and still be well under the max psi found on the sidewalls. Max Psi and door jamb numbers might maybe be accurate occasionally but never assume them to be correct without knowing the load each tire is actually carrying.

Just sayin...

:C

[cbigham]

I've already done the math. I set off at 76 lbs, came in at 82, 83 lbs??

[CA_Traveler]

Congradulations you have the first step to setting the correct tire pressure. Go the the tire mfg load inflation table for your tires and set the tire psi per axle per given weight when cold as indicated. Weight is based on fully loaded, full fuel, water and propane.

Example: My steers are set to 120psi and duals to 90 psi based on axle weight and 2 vs 4 tires on the axle, same tires.

Max psi is used when you don't know the weight or think you know more than the tire mfg.

I've seen 140F internal tire temps, just keep on trucking.

[DrewE]

I wouldn't be worried. If one tire were noticeably hotter than the others it would be good to give that one some scrutiny as it may be low or delaminating internally or something; but tires generally getting quite warm in use is normal. (I'm assuming the cold inflation pressures are correct for the weight they're carrying; pressures when they're hot will of course be higher per the ideal gas law.)

I highly suspect the smell comes from something other than the tires.

[PartyOf_Five]

Our 31' has a lot of extra weight on that rear axle regularly so we go overweight regularly so we need to keep them at the max 80 psi. Never noticed a smell but we watch the speed on hot pavement, sometimes even deliberately choosing to drive early/ late.