My Tires are no longer round ? ? ?

[Mrwurm]

I have a Gravely Promaster 260Z Zero Turn Mower. It has about 250 hrs on it. Its 4 or 5 years old. My front tires are Titan Super Guide 4 ply. One of the tires went flat after I ran it through a deep rut. The tire was leaking at the bead, so I inflated to 30psi (the max rating) and it resealed itself. While I was at it, I filled the other tire to 30 psi also. The next day I walked past the mower and immediatley saw that both tires are mis-shapen, bulged, and dented on the sides. Too messed up to operate the mower without bouncing up and down. I jacked up the mower and let all the air out and let the tires sit for 5 days. I then filled them to 20psi, and they are right back to being mishaped. I drove around a bit and it did'nt improve. What happened to my tires ? ?

(rims are not bent and do not exhibit any noticeable run-out)

 

[Bird]

Jerry, some of those little tires don't have the cords in them that most tires have, so you can blow them up like a balloon, but as you found out, that weakens the spots that stretched. You might be able to put lots of a stop leak like Slime in them and with low enough pressure get them to stay the right shape, but it's my guess that you're about to get a couple of new tires.

 

[JerryG]

Keep an eye on them. The last time I had a set of tires that did that, they soon came apart. The cord separated inside the tire. I put on 6 ply after that and had no more problems.

 

[bontai_Joe]

I'm 99.9 percent sure that you need new tires. The old ones have been permanently strstched beyond their limit.

 

[Mrwurm]

Looks like the predictions were correct. I wrestled one of the tires off the rim and found that all the plys were unraveled inside. The tires look like they have a wad of spaghetti in them.

New tires are on the way !