Extreme tire wear inside right, why?

Just got back from Rudskogen racetrack in Norway and found out that I have massive tire wear on both front tires on the inner side. It is more visible on the right side even though the track is driven clock vise.

At first I thought that it was camber related but after asking around it is pretty clear that the angle isn't camber. Most of my friend seem to think it is toe-related. Anyone that can explain how toe can cause this type of wear pattern?

The car is a 430 Scuderia with -3,5 degr camber and 0 toe at the front. Tires are Pirelli Trofeo R 245/35-19 at the front on original tires.
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That's a fair bit of camber and if mixed with even the slightest bit of toe out you'd accelerate inside wear in a big way.

Maybe the toe is not zero as you think.

Maybe you have worn suspension components which are allowing the toe angle to spread under brakes and corners?

Too high pressure could also be a contributor.

Mix a little bit of all three and premature wear sets in.

I'd lean towards toe being positive (out) even though you think it's neutral.

P.s. - I don't know the track but if there are long braking sections at the end of fast striaghts you'd really be loading up the front inner as the shocks compress and spread the camber out even more.

 

A little hard to tell in a photo but it does look like a toe problem.

Toe makes the tire get dragged sideways across the pavement. Just a little toe in is used for stability, making the car track straight ahead. Just a little toe out is often used to make a car turn in better but in trade for its desire to just go straight down the road.

It does not take too much toe in or out to cause real wear issues. Also if the car has been lowered or if the camber has been changed it will have a big effect on toe settings unless that was taken care of at the same time.

 

I think you may be right. When I did camber and toe last time I made sure not to get too much to-in so I was probably leaning towards toe-out rather than toe-in. I will check again. The suspension on the Scud is tight as far as I can see, so that should not be the problem.

The funny thing about you asking about the fast straight is that on this track there is a fast straight with a brake section that is downhill, and at the same time makes a right turn. This is probably why I haven't experienced this wear pattern at the other tracks. Take a look at the youtube movie, the section is after about 35-40 sec. It is a lot steeper than it looks in the movie and the compression is massive...

https://www.youtube.com/watch?v=LbL3yWFOvVM

 

Nice video! Can't beat Harry's - it just does what it says on the tin.

For sure there's hard braking at the end of main straight and then again, from the same top speed, at the end of the second straight with the big drop you mentioned. That's hard work for tyres set at 3.5 degrees but I can't help feeling you don't have zero toe.

Looks a nice track but, plenty technical. Lot's of practice required to get the times down I'll bet.

 

Yes, of course it is the camber!!! That is the camber for the best grip but does cause major inside wear. You probably also have understeer but that is the safest set-up. You should see the inside of race tires. Either Ferrari Challenge or Porsche Cup. You need all that camber because radial tires roll under during side load. Any less camber is less grip.

 

You are correct about the under-steer, the track feels like it was built to give you a lesson in under steer...

At what part of the track would you say that I get this wear angle? If you put the tire on the floor and lean it to mach the contact patch, it is an extreme angle maybe 8-10 degrees or more. I don't understand where this happens. Is it when cornering, and it is the inside tire and not the outside?

Rudskogen is a very technical, and with on the long curves leaning the "wrong" way, at least in my mind it would make sense to think that the inner tire gets "dragd" in an extreme angle. Putting a bit of toe-in sort of make sens when I think about it...

 

All the data was ok, camber was at -3.5 and toe 0. I changed to 1 mm toe-out. Turn-in was a little better and high speed corners was a lot better and stable.

35 laps on a Kinnekulle didn't result the earlier inside wear result. I have been on this track many times before and I have never had this problem so I am not sure this test proves anything though... We will know for sure after next visit to Rudskogen I guess...

A few notes on the Michelin Pilot Sport Cup2. Lap times were at least 2s slower on this technical 1 minute race track compared to Pirelli Trofeo R. For track use, there is just no comparison. As a compromise for use in the wet I am sure it is ok, but if you want to set track records the Michelin need to stay at home...

A couple of laps at Kinnekulle on MPSC2, great weather and perfect conditions

https://www.youtube.com/watch?v=plvR-VPz6jc

 

For track use I put a set of Pirelli slicks from the Challenge series on a separate set of wheels. The car was much better at the track. All worked very well and I did not ruin a set of street tires. The other issue was tire pressure build up. I tried to keep them about 30lbs. Anything above that and understeer came back. The Stradale is set up for understeer. The front wheels are too narrow at 7.5" and the front tires are too small at 225. 235's help and trail braking into the corner puts more weight on the front tires as you turn in. The Stradale is an amazing car at the race track. Just uses a lot of tires. But anything that weighs 3000lbs is going to use tires up. Have fun and don't forget to listen to engine )

 

I ran with -3 camber and 2mm out and did find that inside front wear was much more pronounced than same camber with zero toe. The feeling is great (in the corners) and not so good on the straights (particularly high speed motorway) but wasn't worth the additional tyre wear for me anyway.

That's an extraordinary difference between two tyres one would have thought would be in roughly the same "family". I'm very surprised.

Do please report back after next trip to Rudskogen