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Topic: tire & tire pressure question (Read 1516 times) previous topic - next topic

Re: tire & tire pressure question

Reply #20 –
I have had many experiences as a Foretravel manager with tire pressures/ride quality issues.

One that comes to mind was a customer who traded in a 78 35' dodge with its air tag for a 29' Chevy grand villa.

Rare.  Extremely.  To go smaller.

Had to order in the hydraulic jacks from Mike grimes so two weeks later they brought their 29' in for the install.

Their old coach was in service not sold yet and they asked to see it again.

DW mentions how nice the coach was "but it rode so bad" 

Light came on over my head.  OMG.  Kicked a tire and almost broke my toe on the 8r/19.5. 

They left and I took a tire gauge with me back to service and  all the tires were full sidwall pressure. 

Drove the coach and everything rattled. 

Dropped the pressures and it was like on pillows.

Perfect

Told a lot of customers the story

Re: tire & tire pressure question

Reply #22 –
Quote from: Bob & Sue  -  23 hours ago
Fill the tanks. Check the Michelin guide. Add 5LBs of air above 4 corner weight figure. Done

Our 280 is at 75 front and 90 rear per Michelin.

I would assume that's backwards?
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 I will be re weighing the coach today but per Michelin chat the pressure is over some.

Re: tire & tire pressure question

Reply #23 –
Quote from: wolfe10 –
I agree.
I don't understand why this would be considered backwards, the MFG plate shows the pressure for the MAX  GAWR to be 85psi single and 90psi dual for the GVWR of 28,000 or 10,000 front and 19,000 rear. The OEM tires were 275/80 LRG. Using a LRH rated tire you should be able to run slightly less pressures for the same weights as the LRG.
Maybe I am missing something?

Re: tire & tire pressure question

Reply #24 –
First time I have seen a Michelin chart to my memory where the tire pressures do not drop the same percentage of max as the load.

Thanks for bringing this up.  Michelin is saying that at a certain percentage below the max for load and pressure that the pressure decouples the ratio between the two and the pressure drop starts increasing faster than the load is decreasing.

big difference in the front axle weight on our u320 at 12k versus your u280 at 10k.

Our rear is 20k yours is 19k.

Five percent difference on the rear and nearly twenty on the front.

I would have overinflated a u280 fronts without the chart. 

I would wonder if using "h"s and the corresponding even lower pressures might show different handling.  Squirm?
 

Re: tire & tire pressure question

Reply #25 –
Bob,

Perhaps I missed it, but please post your 4 corner or axle weights.