Feathered vs Non Feathered

What is the general thought between pulling tires off that are feathered vs tires that are NOT feathered (at all)?

Personally, it seems to me that a tire that is perfectly smooth with little feathering after a race tells me the tires really are NOT working. Grip should stretch rubber build heat and feather. Too much feathering tells me the tires are too soft. Therefore, does it mean tires with no feathering are too hard?

Went out in Hot laps and feathered some tires in 8 laps. We didn't feather another tire at all the rest of the night with three classes running 20 lap features.

I would like to see some slight feathering preferably about the same on the RR, LF and LR.

Is this wrong? Better off with a perfectly smooth tire?
 
Define "feathering."

I define "feathering" as the rubber being torn from the surface of the tire and peeled back like dead skin from a bad sunburn, (ie excessive wear.)

Now, I call "graining" as the rubber wears evenly with a surface similar to sandpaper. (Just the right amount of wear.)

You are correct that a tire needs to build heat to work best, but excess heat generally means excess wear.
Too soft, and it wears excessively; too hard, and it doesn't wear at all.


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
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35 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Define "feathering."

I define "feathering" as the rubber being torn from the surface of the tire and peeled back like dead skin from a bad sunburn, (ie excessive wear.)

Now, I call "graining" as the rubber wears evenly with a surface similar to sandpaper. (Just the right amount of wear.)

You are correct that a tire needs to build heat to work best, but excess heat generally means excess wear.
Too soft, and it wears excessively; too hard, and it doesn't wear at all.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
www.youtube.com
35 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Fair question. Definitely not blistering. I'm calling feathering that diagonal wavy look that progressively lessons across the surface. It starts on the inside edge and works towards the outside edge. To me the graining would be similar just a very mild case.
 
I posted this in another thread, so parts of it aren't meant for this thread, but it touches on tire wear. Hopefully this helps. The tire wear section is in bold and italics.
I'm absolutely no expert like some others here. But, here's my opinion. Everything we do to tires, from internal, external, fresh vs cured, cutting, and sanding is in the name of Heat management.

-Thick tire, takes longer to heat up, but maintains heat longer, and potentially reaches a higher equilibrium. Which lends it's self to as mentioned above, thick rubber is generally used on colder, softer, wetter tracks. Lower bite tracks that you want that tire to be able to move around. Generate heat and then maintain that heat as long as it was rolled and prepped correctly.

-Thin tire, takes less time to heat up, but will lose heat faster. Generally runs cooler in the long run, but should fire back just as easy, as long as it was prepped correctly.


So when the track is starting to get really hard, especially when it starts to bite up and you'd start to go towards low prep, or no prep Maxxis. If you find yourself thinking, I need an older more durable tire, the track is chewing up fresh tires. But, you see others on brand new stickers, you could be considering a thinner tire. Because, one you're wanting to keep the heat down, and not over heat that tire. If a non wiped Maxxis is "too much" and is still getting chewed up, like it most likely would at Iron City. Then cutting that tire thinner would help alleviate heat in that tire. By allowing it fire off well, but dissipate heat easier through the thinner rubber, and keep the equilibrium a tad bit lower than a full rubber tire. Now, how thin is the question. I know Iron City bites up damn good, so it's something you just have to figure out.

So when a tire wears, it's because it was heated to, or beyond it's optimal temp. So a tires dissipates heat by shedding rubber. That's why you'll almost always see tire wear progress nearly the same on any tire we use for racing.
-No change or looks slick/glazed. Not enough heat to reach equilibrium and probably perform poorly, but not always.
-Very very light graining(Fuzzed), means the tire was pretty optimal but was clearly shedding rubber to lose heat, but didn't need to really lose much heat.
-Light graining(More noticable), means it was slightly hotter than it wanted to be, it was peeling rubber off to help it lose built up heat.
-Heavy graining(Course or big grains lifted), Definitely over heated, but depending on the use it could have been perfectly fine and expected.

-Edges peeling or blistered.(Long waves of rubber laid over each other) Obviously well past it's equilibrium and clearly over heating for various reasons.

Now, the problem this all leads you down a rabbit hole too is that heat is also managed by other aspects as I mentioned above. You have internal, external, fresh tires, vs cured tires, cutting is just another tool in the arsenal. There is no right or wrong way and how you get to the end goal is up to you. This is all essentially thick vs thin for Maxxis only. This doesn't even begin to touch on profiles for cut tires, which in other brands could play almost as big a role. Which most now are only flat cutting the center of Maxxis. Not even cutting the whole tire.
 
Here are the two tires sets that I'm comparing. Both tires had been run in a feature and qualified before.

2023 cut in September 23' (12.42 best lap 5th place)
2022. Cut in March 22'
Both prepped the same. (12.9X best lap) finished around 17th/18th.

The track didn't slow down this much. We seemed to slow down.

The tire with the grain on the inside (left) edge is the 23'. The 22' looks slick on the inside edge and you can see the angle marks from being resurfaced.
 

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That one tire isn't doing anything but riding.
Could be setup, track different one day to the other, etc.....
 
Careful using the term "blistered." That refers to a completely different look.
A blistered tire is often from running too hard of a tire (or one that has sealed over) and the rubber underneath the surface gets molten hot and expands (like a "blister") then pops through the surface. If I get a chance this afternoon I'll snap a couple photos of "blistered" tires from the sprint car.


It would be extremely rare for a kart tire to "blister." This generally comes from over-powering the tires and over-working them to the point of blistering. Sprint cars and late models do this often on dry-slick tracks if you don't control wheel spin. It's also more common on treads - I've witnessed it a few times on the winged outlaw cage karts, but I don't recall a single time on a kart in all my years.

OP, of the two tires, the one with some wear would have been "in" the track more and working better due to higher grip and higher temp. This is why I am not so quick to discount duro as some of my fellow racers are. A tire has to be soft enough to wear (ie grain,) hard enough to not feather. This is the case with all race tires, otherwise they wouldn't offer them in so many compounds.
 
OP, of the two tires, the one with some wear would have been "in" the track more and working better due to higher grip and higher temp. This is why I am not so quick to discount duro as some of my fellow racers are. A tire has to be soft enough to wear (ie grain,) hard enough to not feather. This is the case with all race tires, otherwise they wouldn't offer them in so many compounds.
This is along the reason I posted this. I need to have a plan next time we visit this track. I may just go with a fresher tire and see how we do.
 
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