Michelin Cup threadbare on inside F/NS!

[Pip1968]

Well I still have three laps left of my twenty five as the Nordschleife closed an hour early today due to another accident. They will be for sale should anyone be interested (3 laps for £35).

More importantly I changed my Cups back to PS2/ Michelin Super sports for the journey home and to my dismay found the inner near side front tyre worn to the canvas (only the inside inch or so). Something has obviously caused some serious rubbing. There did not seem to be any play in the wheel so presumably not the ball joint. Steering? Any ideas appreciated. She is going to ELMs on Wednesday so perhaps it will be obvious to them.

Pip :bigcry:

[shimmy]

Toe or worn bush

[_Nathan_]

Yep, too much toe out will do that.

[Pip1968]

Well I made it back to Blighty with a wheel change for the route back and do not seem to have suffered the same excessive wear but will get her checked at ELMs tomorrow. Thank you for the prompt replies.

By the way Shimmy I met your mate John Stevenson at the Lindner with his lovely and much used 996 GT3 RS.

[shimmy]

Stevo is a star.:thumbs:


And plenty of tread left on that there tyre. :whistle:

[s.mac]

You need to check the 4 wheel alignment, that's not good on a tyre with that much tread on :(

[northernjim]

Yep, too much toe out will do that.

2mm toe out and 2.5and over camber will ruin a tyre on the road in quick time:whistle:

[Pip1968]

Rather unashamedly although I have Turner adjustable top mounts I have not adjusted her toe in/out for track, she is presumably completely neutral. Giraffe looked at her today but only came up with the front the coil springs being incorrectly seated. Would that have caused the excessive wear and on one side only - ??? I am not convinced.

On top of that I can only add two other points. Firstly the coil springs have either been like that since I bought her 11,000 miles ago (mostly track and travel to and from - only Nordschleife) and without a similar problem before. Secondly BMW Maidstone looked at my suspension although this was due to the car sitting unevenly and the problem was at the rear so presumably they did not dismantle and reconstruct the front suspension.

I did ask BMW to look at the bushes et cetera with a note of the problems encountered.

Finally I should add that I did ride the curbs at Hatzenback, just before Adenau, and at Eschbach and on the uphill left after Brunchen. Maybe it was that.

Pip

[glendog74]

I ruined a pair of front PS2s back in 2008 as I began to get quicker at the Ring with standard settings/minimal negative camber. :banghead:

You are obviously getting quicker around the track and should adjust camber settings to avoid the issue as described above.

Riding kerbs would have negligible affect as the car is unloaded on the side which runs over the kerb unless you like to live dangerously by riding the outside kerbs when cornering lol!

[shimmy]

Toe changes with camber so if neutral toe is set for road camber, likely that you are running huge toe for track which wil wear tyres quickly.

With adjustable top mounts you have to tread a fine line with toe so road and track are either side of neutral

[northernjim]

running it with low pressure can exacerbate the problem too I think?



ie set tyre when hot then drive home without adjusting pressure back up to road pressures

[cslsuperfan]

Well I made it back to Blighty with a wheel change for the route back and do not seem to have suffered the same excessive wear but will get her checked at ELMs tomorrow. Thank you for the prompt replies.

By the way Shimmy I met your mate John Stevenson at the Lindner with his lovely and much used 996 GT3 RS.

Pip I had the very same tyre damage on a front set of cups a few years back. BMW diagnosed seized control arms on both sides. Replaced both arms and had a full kds alignment. Never re-occurred...however my car hadn't done 22 laps of the ring!

[Pip1968]

As said the road tyres do not seem to have suffered on the 300 mile journey back home so I am thinking that maybe the situation was exacerbated/caused by low tyre pressure.

When I changed the PS2s to Cups just down from Am Tiergarten I did not tyre check pressures. I then started lapping with short breaks and came in after doing probably nine laps that day. I decided to give her a rest and a chance to cool down and check tyre pressures. The NSF was at 20psi I seem to remember whilst the others were happily at 30psi. I pumped it back up and did not think anymore of it. Luckily it was 1800 and the Nordschleife coincidentally announced that they would not reopen for the last hour due to an ongoing incident. It was only then as I swapped the tyres back for the journey home that I saw the damage/wear.

I may get KDS done anyway. Anyway, surely Giraffe would have noticed the control arms (apologize for my ignorance - I only dabble in mechanics) especially as I told them at ELMs about the excessive wear NSF.

Pip

[Pip1968]

Just thought that I would update this thread to say that Giraffe very kindly had a look at my problem as I popped up to ELMs for an oil service. The only thing he found was that the coil springs were the wrong way round. I am unsure how much effect this would have and they will only have been changed by BMW Maidstone when they investigated the car sitting lower on one side last year (I have probably only done ~1,000 miles since then and that would have been mainly this trip to the Nordschleife).

I did however look at some pictures I took of my two front tyres last year before I got rid of them. The Pirelli (on the car when I bought her in 2007 and subsequently only used for track) NSF has worn slightly more on the inside edge although not as severely and as narrowly as the Cup. Perhaps a sign of things to come last year. Or a problem exacerbated by me running with low pressure in this tyre.

Anyway I should utilise my Turner adjustable top mounts really so may take her for a check up and adjusting. Who are the best to use in the south-east - Simpsons/Thorney......or anyone around Brands Hatch who knows their trade (ETA)????

Pip