Community Forums

Charlie and Martha · 01-08-2020, 08:36 AM

Quote:

Originally Posted by NWIP

Charlie

Don’t think you want to interpolate (77.5), use the higher 80psi for the rear.

Agreed

Quote:

Originally Posted by GaryKD

Michelin does not want less ten 85 PSI in their tire regardless of weight.

Ok, so where do I start here? It, seems that each twist and turn changes the possible PSI. Based on the Michelin recommendation of nothing less than 85#'s PSI should I assume 85#'s in all six tires?.

Dutch Star Don · 01-08-2020, 09:24 AM

Earlier, I gave you weights of almost the same weight coach. I would never start the fronts at 85 psi, unless it was a gasser. Again, start the fronts at a 100 psi, which will be quite a bit softer than the 110 you're running. See how it steers. Too much pressure can make the front end squirrely. You can also watch the wear which takes a little longer to see. Under inflated will start to wear the edges more and over inflated will wear the center faster. Starting at 100 psi will still give you 5 pounds or so to reduce even more, without getting too low on the front.

Running the rears at 85psi is as low as I would go on them. The only reason to change that pressure is if you see the tires squatting, they're running warmer or getting more tread wear on the outer edges of the tires.

Charlie and Martha · 01-08-2020, 10:22 AM

Thanks Don, Dave, Txcpl, NWIP, Algoma, Gary, Richard, Nutcrker and if I missed someone, you too.

Done,, I wasn't blowing off your recommendations. Especially since the weights were similar. I was/am just trying to get a better understanding of where I should be and why.

I am going to start with 100 PSI in the fronts and 90 PSI in the rear and then check for squatting and wear as we go. The coach exhibits squirrely behavior when the road is grooved or tracks from traffic have formed. It yanks you all over the place. And the harshness of the ride is really stiff. Control in heavy wind is much improved with the new Koni shocks but that is almost negated by the squirrely behavior.

I have been watching these tires closely over the last three years looking for cracking, uneven wear or other signs of trouble. I do have a TPMS system and monitor it while on on the road. The goal is a softer ride and better steering. I will make the pressure changes and see what happens.

Oh, and Don. I haven't forgotten about the docking light project. We've just been on the road for a while and have just landed in Tucson for a while. I will be getting back to that project soon.

Thanks again everyone

richard5933 · 01-08-2020, 12:49 PM

While the correct pressure will help correct some road behaviors, I've found that some tires just have bad manners on the road. I've replaced nearly brand-new tires on a car in the past for doing something similar to what you describe. The roads where I lived were frequently grooved (in the direction of travel) to help reduce hydroplaning, and the particular tread pattern just didn't work on those roads. It wanted to follow every squirrelly groove it found.

Not saying that your tires themselves are the problem, but some have tread patterns that produce better road manners.

Dutch Star Don · 01-08-2020, 03:14 PM

Charlie, you get those tire pressures dialed in, you should see some pretty good improvement. I'm really anal about pressure and have spent almost six months testing pressures (six months because you don't drive it everyday). Report back what you find, as we'll be curious to see if some of the issues are reduced or cured. I felt my 2019 was steering was a little squirrely until I got some miles on the new tires and lowered the front pressure 10psi.

Martha will be happier too…..if that ride softens up!

Lastly, I've changed out shocks, added Centramatics and lowered pressure as low as I can safely go. My coach rides fairly well, but there are still some roads, especially in California, that will make your teeth rattle.