Issue with K02s- Slippery under hard braking normal?

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SocalRunner15

New member
Hey Guys,

I recently popped on some 265/70/17 C Class K02's on my 3rd gen (using some sr5 wheels from a newer 4runner. I'm running them at 38 PSI and i've driven about 1,500 miles so far.

I quickly realized that when i brake hard, they feel like they want to break traction really fast. I don't remember my goodyear duratracs behaving like this. Even under moderate braking, it just feels like they're just barely Not skidding forward.

Is this normal behavior with the K02s? This is in completely dry weather btw...in rain it seems to get worse. Any thoughts would definitely be appreciated.
 
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SocalRunner15 said:
Hey Guys,


I quickly realized that when i brake hard, they feel like they want to break traction really fast. I don't remember my goodyear duratracs behaving like this. Even under moderate braking, it just feels like they're just barely Not skidding forward.
Click to expand...

Have you ruled out the ABS system? I don't brake hard very often, but the ABS feels weird to me when it does activate.
Also, it would be helpful if you state the year/model of your 4Runner (I put mine in my signature) so folks with year/model specific knowledge can contribute. The braking system changed around 99 or 00 as I recall.
 
The right tire pressure can have a significant impact on braking. Adjusting it a bit could help optimize grip during hard braking.
Also, the type of tires you have also matters. These K02 tires are made for off-roading, so they might feel different when you brake.
Plus, check your brakes. Brake pad wear, rotor condition, and brake fluid quality can affect how well your brakes work.
 
38psi is probably too high for K02's in C load range unless you are towing or heavily loaded.

Rear AWR: 3000lbs (1500lbs+margin for each tire)
Front AWR: 2650lbs (1325lbs+margin for each tire)

Even at 35psi (lowest published inflation pressure for the K02), they are rated at 1890lbs each.

I run 35psi on mine and have heavy front bumper, winch and full skids on there all the time - and I could probably go lower if I wanted, even down to the OEM 30-32psi. That would lose some MPGs.

All that said, the K02s aren't great on the road, especially in the wet. You may also just be feeling the tread blocks squirming (small and tall tread blocks from an AT tire) - are you getting full ABS activation or just handling characteristics you aren't used to?

-Charlie
 
phattyduck said:
38psi is probably too high for K02's in C load range unless you are towing or heavily loaded.

Rear AWR: 3000lbs (1500lbs+margin for each tire)
Front AWR: 2650lbs (1325lbs+margin for each tire)

Even at 35psi (lowest published inflation pressure for the K02), they are rated at 1890lbs each.

I run 35psi on mine and have heavy front bumper, winch and full skids on there all the time - and I could probably go lower if I wanted, even down to the OEM 30-32psi. That would lose some MPGs.

All that said, the K02s aren't great on the road, especially in the wet. You may also just be feeling the tread blocks squirming (small and tall tread blocks from an AT tire) - are you getting full ABS activation or just handling characteristics you aren't used to?

-Charlie
Click to expand...


Hmm...these are all great questions. So i was running wrangler duratracs before and they didn't do this under hard braking....it was more of a linear feel.

With the K02's i'm getting sliding even with moderate braking.

I'll play with the psi's as you guys mentioned and see what happens
 
SocalRunner15 said:
Hmm...these are all great questions. So i was running wrangler duratracs before and they didn't do this under hard braking....it was more of a linear feel.

With the K02's i'm getting sliding even with moderate braking.

I'll play with the psi's as you guys mentioned and see what happens
Click to expand...


Too much pressure and you’re driving on center of the tire. Not enough and you’re driving on the outside edges.


Sent from my iPhone using Tapatalk
 
Maybe off topic but my KO2s slip in the rain quite often. I thought it was the way I drove but I watched a youtube video of a guy saying the exact same thing and he switch to open country because of this.
 
I thinnk 36 is too high, i run about 34
you can do the chalk test. Find an empty parking lot. put a chalk stripe on each tire. put each tire at a different pressure. say , 35,, 34,33,32

drive a few of feet mulitiple revolutions, straightforward and get out and look at the chalk on tires
example gone in the center but still on outside edges, too high
gone on outside and still in center....too low
want completely gone all across
 
pluton said:
Have you ruled out the ABS system? I don't brake hard very often, but the ABS feels weird to me when it does activate.
Also, it would be helpful if you state the year/model of your 4Runner (I put mine in my signature) so folks with year/model specific knowledge can contribute. The braking system changed around 99 or 00 as I recall.
Click to expand...

2001 was the change with electric master cylinder and trac/abs
 
Do the chalk test as stated above. That is where you find optimal psi for said vehicle and set up. IIRC I'm running somewhere between 28-30 psi (totally different tire then the ko2, micky Thompson baja boss in e load) and it rides amazing and brakes great.
 
Bruski said:
Maybe off topic but my KO2s slip in the rain quite often. I thought it was the way I drove but I watched a youtube video of a guy saying the exact same thing and he switch to open country because of this.
Click to expand...
I'm in the market for new tires very soon... and I'm hoping I can hold out for the K03s in the size that I want (265/70-17, LRC; LRE is currently available). They should be better on the road, especially in the rain due to an updated tread pattern.

-Charlie
 
phattyduck said:
I'm in the market for new tires very soon... and I'm hoping I can hold out for the K03s in the size that I want (265/70-17, LRC; LRE is currently available). They should be better on the road, especially in the rain due to an updated tread pattern.

-Charlie
Click to expand...


So i decided to change out the k02's for k03s- they had some 30 day ride guarantee. They only have the e class in 265/70/17 though. C class is coming out in august. i lowered the psi on the k02's and honestly they were still super slippery on dry pavement. Compared to my duratrac wranglers....it was maybe 30% of their grip level. Not sure if they were defective, but i didn't feel comfortable with them.

I'll go ahead and do the chalk test on these and see what the optimal psi's are for the K03.

As far as the ABS system goes- mine are terrible. As in 'They are trying to kill me in the rain' terrible. When it gets wet....i drive extremely cautiously. My previous tires were duratrac wranglers...i'm hoping the k03's will prove superior in the rain but we'll see.
 
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They're a little squirmy when new. All that siping lets you move around a bit on hard surface. It'll get better as they age a little. But you're probably also overinflated. I've ran mine at 34psi for years, ride great and feel pretty planted.
 
Same here. They say August for the size I use...I have trips planned for the San Juans in Sept and W AZ in Oct.
My KO2s pretty chewed up...they always sucked when it rained...but I have never had a flat.
 
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