What PSI is everyone running?

jeepmikey

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Curious what PST everyone is running for normal / street driving? Had new KM3s mounted on AEV Borahs today - shop aired them at 40 PSI and after driving is closer to 41 PSI. Wondering if this is too much?
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Curious what PST everyone is running for normal / street driving? Had new KM3s mounted on AEV Borahs today - shop aired them at 40 PSI and after driving is closer to 41 PSI. Wondering if this is too much?
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roaniecowpony

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Still on my stock Rubicon K02 33s running 32 at warmed up temp. Steers much better.
 
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jeepmikey

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35x12.5x17

Also, to avoid multiple threads - does anyone have experience balancing vs. road force balancing? I know the KM3s are mud tires but past 60MPH vibration starts. I'm coming off the stock Falken MTs and granted these are 35s vs 33s should not have the vibration. Wondering if it's the PSI, balancing or combination of both.
 

roaniecowpony

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Check your tires for running true. If they run out too much, balance won't matter.
 
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jeepmikey

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Check your tires for running true. If they run out too much, balance won't matter.
Apologies, when you say check your tires for running true - not sure what this means? To confirm, and not sure if this matters or is helpful - I just picked up the new 19 JLUR yesterday and put 100 miles on it with the stock Falkens.

The AEV Borahs made for the JL were mounted today with 35x12.5x17 KM3s - reviews as a whole praised this tire. Shop swore balancing was done right, I'll air down to 45 PSI but not sure if should find a place that does road force balancing or how to check if "running true?"
 
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jeepmikey

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I’d air down to 30 psi warmed up and try that first.
Is it possible being at 40 PSI would cause vibration vs being aired down to say 30 or 35 PSI?
 
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jeepmikey

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Yes , it’s possible.
I’ll air down to 35 first tomorrow to see how the rig drives.

Still curious to understand how to check if the tires are “running true”
 

roaniecowpony

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Apologies, when you say check your tires for running true - not sure what this means? To confirm, and not sure if this matters or is helpful - I just picked up the new 19 JLUR yesterday and put 100 miles on it with the stock Falkens.

The AEV Borahs made for the JL were mounted today with 35x12.5x17 KM3s - reviews as a whole praised this tire. Shop swore balancing was done right, I'll air down to 45 PSI but not sure if should find a place that does road force balancing or how to check if "running true?"
Large tires are difficult to manufacture so they run true. Runout is a term used by various manufacturing industries to describe the lateral and radial dimensional variation of round articles intended to rotate around an axis. In our case, rotation is around the wheel hub bearing axis. Adding to the issue, mounting the tire on a beadlock type rim has to be done well. If the installer doesn't get the bead setting on the shallow step correctly, it can run out a lot and vibration can happen.
 
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jeepmikey

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Large tires are difficult to manufacture so they run true. Runout is a term used by various manufacturing industries to describe the lateral and radial dimensional variation of round articles intended to rotate around an axis. In our case, rotation is around the wheel hub bearing axis. Adding to the issue, mounting the tire on a beadlock type rim has to be done well. If the installer doesn't get the bead setting on the shallow step correctly, it can run out a lot and vibration can happen.
Many thanks for all of the responses - I’ll air down to 30 tomorrow and see how they run. There’s a 4x4 shop in CT I’ll take it to next week if continue to have vibration - I’m leaning towards it not being the tires but shop that did the install / balancing. Even though I asked 10x if they’re confident in balancing this specific set, I texted the tech after with the vibration complaint and told me to bring it back - “weights must be off”

Also wondered if adding the protection rings after balancing would make a difference?
 

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I have 285/70 17 KO2s. I did the chalk test (draw a line across the tread from one sidewall to the other, and drive a few hundred feet. If the middle goes first: too much pressure, if the outside goes away first: too little) and 33 psi cold was spot on.
 

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26 cold
 

roaniecowpony

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Many thanks for all of the responses - I’ll air down to 30 tomorrow and see how they run. There’s a 4x4 shop in CT I’ll take it to next week if continue to have vibration - I’m leaning towards it not being the tires but shop that did the install / balancing. Even though I asked 10x if they’re confident in balancing this specific set, I texted the tech after with the vibration complaint and told me to bring it back - “weights must be off”

Also wondered if adding the protection rings after balancing would make a difference?
If I understood correctly, you had the tires mounted inside the rim in standard DOT approved manner, balanced them and then added the protection rings later? Yeah, that has the potential throw them out of balance quite a bit.
 
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