Learning how to diagnose tires


(Paul Fox) #1

Was reading the tire pressure thread and there is a lot of great info in that thread. I’m sure I’m not the only one here, but I’m not at the point where I could tell someone I like my tires at x psi or probably couldn’t even tell the difference of how the kart handles differently at certain psi. I also think it’s a very important skill to properly read tires as it really tells you the whole story to what’s going on.

So I thought it would be cool for members to post pics of their tires and we could diagnose them to see if we get them right. Then hopefully more of the experienced members could let’s us know if we were right or not. Could be a cool exercise and a very important one… lmk your thoughts!

Any special considerations for older Chassis setup?
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(James McMahon) #2

Cool idea, thanks for posting!

(Paul Fox) #3

I’ll get some pics of my tires soon to kick off this thread! In the mean time let’s see everyone’s. (Tires that is :joy:)

(Davin Roberts Sturdivant) #4

That is an interesting idea. I’m doing a test day tomorrow on some used tires, so if I remember to take pictures, I’ll post them.

(Paul Fox) #5

Sounds good! Taking pics on old and new yellows this weekend.

(Paul Fox) #6

(Paul Fox) #7

So I recently flipped the tires and have I think one session on them in this configuration. So that’s why the tires wont make sense as far as how the are mounted currently.

So I would say the fronts obviously have substantial graining, which means they were oversterring? And possibly too much psi? I set all tires at 9psi cold FYI. Weather has been high 80’s low 90’s

As for the rears I feel the one tire looks fairly normal but the other looks over inflated to me by looking at it.

Again I hope the porpose of this thread is to A. help diagnose what the tires are telling you and know how to adjust psi and B. how chassis set up effects tire wear.

Let me what you guys think!

(TJ Koyen) #8

The tires look pretty normal to me Paul. I don’t see any graining on the front. Also, graining on the fronts indicates UNDERsteer, not oversteer.

Also, side note, I would avoid flipping the MG Yellows on the rim. We’ve always found that flipping them (especially the fronts) really messes up the camber of the kart and really takes grip away. They might start to come back as they re-profile from driving, but definitely the first few sessions you’ll notice a lack of grip after flipping.

Harder tires it isn’t such a big deal. But on a softer tire with an especially square profile, you’ll end up riding on a smaller contact patch if you flip them.

(Michael Jones) #9

that’s an interesting opinion on flipping the yellows TJ. lots of guys over hear (Western Austrailia) flip them on the rims every heat.

(TJ Koyen) #10

If you flip them every heat it’s okay because the tires don’t develop all that camber on the inside edge.

(Jamie Gonzalez) #11

Few questions:

1: Excessive rubber pickup on tires?

Seen some suggestions online that indication of to low hot tire pressure. Seem accurate? I noticed this past weekend regardless of how I entered pits I always came in with a TON of rubber pickup. Kart in front of me in tech line did not have same issue.

2: Rear tire inner edge coning? In general it seems that I tend to cone the inner edge of tire pretty excessively. Overall balance of kart seems ok just cone tire. 3 different tracks I have varying degree of coning but does seem excessive as when inner edge is down to wear bar the outer edge is still has about 30-50%.

Does this indicate general setup/driving issue?

(Paul Fox) #12

Here’s brand new yellows with 4 sessions on them.

Started out at 8.5 psi. Felt ok and tires look normal to me. Any thoughts?

(Davin Roberts Sturdivant) #13

Somewhat related-ish, but I came across a video about reading kart tires that I thought might be somewhat useful here.

(Steve Wright) #14

Would you say the MG Reds fall into the soft category? Can they be flipped to use as practice tires and not mess up a driver? Is it better to just buy new tires so the driver is used to new tires?

(Paul Fox) #15

Reds would be a hard compound

(TJ Koyen) #16

They are a medium/hard compound. The MG Yellow is the medium/soft compound in the range. You can flip Reds, they don’t wear nearly as much as the Yellows.

However, you bring up a good point. It isn’t a bad idea to have your driver practice on new tires every once in a while. There is definitely a difference in driving and setup on fresh rubber.

(Andrew Maldonado) #17

I am looking for some help as well. On Vega Reds for for the 3rd time. My first 2 times tires came off looking great. No build up and rears looked like sand paper. After my 3 race it was a while different story. It was only left sides and didn’t go off track or out of the racing line. My top speed was continuing to slow down as the day went on. I’m still new and trying to understand. I have read so many different reports about tire temps and pressure. So I’m leaning towards the tire pressure to low and not getting hot enough.

(James McMahon) #18

My guess is there was more clag/marbles/buildup in the later sessions that you picked up.

There’s too much on there to read really. We can see you have camber burn, but often that’s where the kart is fastest.

In the last session, when did the kart “come in”. Early? Late? Was the last session longer than the others?

(TJ Koyen) #19

Picking up rubber like that is generally a sign of not generating enough heat on that side. What pressures were you running?

(Ben Marshall) #20

Hi all,
This was after quali and 1 heat.
Does the inner wear and outer edge no wear suggest bad setup?