Tyre chunking

[Kikiriki²]

This isn't yaris gr related but since you guys drive hard I thought you'll have an answer.

On my yaris 1.3vvti I've got a problem with tyre chunking (pics below). Tyres were made in the end of 2023 and are yokohama advan fleva v701.

I drive the car as fast as it can go (does it wonderfully with great controll and road feel) but seem to be breaking chunks of my tyre off. Is this normal when driven hard or am I missing something?

 

[skidlid]

Simple answer, drive slower. You do know its illegal to break speed limits.

[Bper]

Hi Kristjan,Tyre chunking, where bits of tread break off, can happen for a few reasons, especially with hard driving like you’re doing. Your Yokohama Advan Fleva V701 tyres are good, but they might not be ideal for pushing the limits as much as you are.If you’re cornering hard, braking aggressively, or driving at high speeds, you could be overheating the tyres, leading to chunking. Incorrect tyre pressure, especially if too low, can cause overheating and damage.These tyres aren’t meant for extreme driving, so they might be wearing out faster. Rough surfaces or sharp edges can also damage tyres.To reduce chunking, check your tyre pressures, alignment, and suspension. If you keep driving this way, you might need tyres designed for more aggressive driving.But as said above reduce your speed it will not only prevent you from causing potential accidents but greatly helping to reduce and eliminate your tyre chunking.🙂

[Mooly]

Those tyres are advertised as 'advanced high performance and sports oriented'.

Complain to Yokohama and see what they say. If a 1.33 Yaris can actually take chunks out of them then presumably anything with a bit of performance would annihilate them. There is a difference between normal high rate wear caused by harsh driving and bits falling off them. That assumes you are driving on a normal roads in decent condition and not on unmade roads and tracks.

There are a lot of unknowns here...

[TonyHSD]

These chunking are normal and can happen on any tyre make or model. 
There is nothing wrong or unusual here except high wear on the outer edge which most likely is as a result of under pressure and high speed corners. 
Chunk off happens while doing manoeuvres on uneven terrain or bad roads, hitting potholes, going over sharp stones etc. Can also be from rubber compound but then the chunk will look like rock erosion, here it is not. 
If you drive like on rally don’t expect your tyres to last long. , perhaps the car won’t last very long either. 

[MikeSh]

4 hours ago, skidlid said:

You do know its illegal to break speed limits.

He's non-UK so we don't know what is legal.

[Cyker]

I've had that edge-stippling - It's classic overheating from cornering too hard; I used to get it after hooning about in high summer on particularly twisty roads when I kept the tyres at stock pressures; I figured it's allowing the corners to deform too much under hard cornering so they rub and heat up.

I also got noticeably more wear on the edges of the tyre than the middle. Upping the tyre pressures a few PSI over stock recommended seems to help - If there is a 2nd PSI rating on the car for high-speed/full load then try those first, but you may have to adjust up/down a bit to find the optimum as it's different for every tyre due to differences in rubber compound, sidewall stiffness etc.

If your Yaris is 2003 then it's a Mk1 and those tended to be quite rolypoly under hard cornering too which adds to the problem!

[anchorman]

I’d be inclined to look at the lower arm on that side.   

[Cyker]

Ooh good point actually, could be ARB or suspension bushes. The OEM ARB bushes in particular are known for being made of grape jelly on the Mk1s   

I kept getting MOT advisories for them on my old Mk1s until I replaced them with polybushes instead.

[Red_Corolla]

If those are the drive (front) wheels, I would say it's just normal feathering of the tread from acceleration forces. I can demonstrate this with my rear motorcycle tyre: Notice how the leading edge of the tread has rounded off from biting into the tarmac, whereas the other side is still crisp? That's acceleration.

 

[Kikiriki²]

Hey everybody! Thanks for all of the replys :D, love to see a community that ingages in so much conversation!

I drive this car on closed asphalt back roads where people practice for rally (so nothing illegal here). 

When it comes to the suspension, the arb bushes are all new (less than 1 month old) but the shock absorbers are oem. I'm about to change them to TRW or Bilstein b4 so maybe that'll change tyre wear.

When it comes to tyre pressure, I've got 2.5bar in front and 2.3bar in rear and only the front tyres chunk.

I also know any tyre will deteriorate when driven this hard but I have to give it to toyota. This mk1 yaris, even when stock, drives and handles great! (even better when lowered) At first I couldn't believe that a car that was made for grandma-like city driving could take so much abuse and still handle corners as well as mine does. In the past I had alfas with 200+hp and this ****box of a 87hp yaris gives those cars a real run for their money.
This is also my first toyota but it seems like it's not my last 🙂

Toyota rocks!!!

[skidlid]

So you are "rally" driving on closed roads.

Of course the tyres will suffer.

Perhaps a set of competition tyres are in order.

[Kikiriki²]

3 hours ago, skidlid said:

So you are "rally" driving on closed roads.

Of course the tyres will suffer.

Perhaps a set of competition tyres are in order.

It's not that I didn't expect the tyres (and everything else on the car) to suffer. I just wanted to know why it's happening and if there's a quirk of these cars that I don't know about. 

[skidlid]

Normal road tyres are not expected to get this kind of abuse. What you are experiencing would happen to these tyres on any car, not just a Yaris. Competition tyres have much stiffer shoulders to prevent this. But this would not be acceptable on normal tyres since the ride becomes much firmer and the tyres tend to follow all kinds of road defects.

Yokohama manufacture tyres that are suitable for your needs https://www.yokohama.eu/en/tyres/motorsport-tyres/ but they are not cheap and not all are actually road legal. The A052 looks to be the only street legal one.