One of my tires has a flat spot???

[Bilito]

It bounces at low and higher speeds, how can I check that, it is very annoying bouncing up and down, I have 12" knobby tires with the direction of rotation on each one, They are spinning the correct way when going forward.

No matter what we do they all look fine, but I think one of them has either a hi spot or a flat spot

[JohnnieB]

Put cart on jackstands and place a stationary object close to tire tread. Spin the tire by hand and the high or low spots should be detectable.

Tire beads that are not fully seated my be the problem.

[Briboy]

Also take each tire off and then reseat them on the hubs, you may have one cocked a tiny bit.

[Swan]

pump them up to 30/35 psi and run it hard , then lower back down to normal psi and see if it helps set the bead . if its in the tread pattern and wont change it

[Bilito]

I jacked up the front of the cart to spin the front tires. I used a heavy can of paint as a stationary object,. the right front is almost perfectly round about a 1/32 of an inch out, the left tire is much more off, close to a i/16 out of round.

I have to move cars around to be able to lift the rear I will report that after breakfast

Right rear is also almost perfectly round, the left rear is OfF about the thickness of an ordinary piece of cardboard which is 3/16 Could something that small cause such a bumpy ride???

What to do????

As an aside: While the rear wheels are up in the air I noticed some play in the rear end and when slowly turning either wheel I could defiantly hear a small grumbling sound which I think is coming and going from the rear end and from inside the rear end itself. I noticed there is only one oil filler plug and it is very near the bottom, so while down here how does one check the grease in the rear end?

[Bilito]

I switched the front and rear left side wheels and went for a ride, still bumps but not as bad, I guess the front suspension is soaking up some of it. I looked at those tire beads real close while the wheels were off and they looked OK,
I can remember back in the day when Recap tires were popular and when you needed tires but were low on cash, most of those tire places had a tire sanding machine attached to the tire installation machine and they could sand off a hi spot. I guess not many folks will recall that era.

[cbdeese61]

I used to have a 4x4 truck with 40" tires and they had to be "TRUED" before balancing or you could not drive it on a road. You may contact some tire companies that sell large mud tires and they may have something to help.

[Swan]

I have my dually tires trued and balanced on the truck . they jack it up and spin the tire and use what looks like a little lathe and the miles come peeling off .

[Cobra,1]

I used to have the tires “shaved” on my sprint carts back in the day to get the diameter matched. No tire is perfectly round when first mounted.

As for flat spot. Over inflate the tire with wheels off the ground.
When you get ready to use cart ,drive it around over inflated until belts/ tire regains it’s shape.

I keep my cart on jack stands during the off season just for that reason, flat spotted tires and undo weight on springs.

Same as my street rod that hardly gets driven. Wheels and suspension unloaded when not used.

[Bilito]

Originally Posted by Cobra,1

I used to have the tires “shaved” on my sprint carts back in the day to get the diameter matched. No tire is perfectly round when first mounted.

As for flat spot. Over inflate the tire with wheels off the ground.
When you get ready to use cart ,drive it around over inflated until belts/ tire regains it’s shape.

I keep my cart on jack stands during the off season just for that reason, flat spotted tires and undo weight on springs.

Same as my street rod that hardly gets driven. Wheels and suspension unloaded when not used.

I am going to try the overinflation rate route, I am looking for a consensus of sorts on how much pressure to use, I have 12 inch Big Knobby tires and run
10 PSI, How Hi can I safely run them. BTW I hate these knobby tires on fancy wheels they wine and make too much noise on paved roads. All I drive on are paved roads, I would switch tires and wheels with someone for good street tires in a second