Track day tyre wear, is this right?
 

my first track day on a circuit that was n't covered in standing water yesterday and my rear tyre seems to have blistered and chunked itself apart in the most odd way, - and other Ducs were n't.
Unfortuantly I know it was n't me riding the thing to fast, - as I was not having a good day, (not in the right frame of mind, but more of that in general messages).

The front tyre looks as a normal track day tyre would, - even blistering accross the width of the tread, however the rear ( a Michelin Pilot sport with only 150 miles on it) was what looked like tearing chunks off of it about 3/4 way accross the width of the tread. The Michelins have diagonal slash cuts going accross the tyre and it was from the leading edge of of this slash cut starting about 1 1/2 inch wide narrowing to a point just in front of the slash cut behind. Looking at the cut tread of that slash cut now it looks to have chamfered off itself, - to me this is odd, andnot right. Checked the presures in the paddock 36psi rear, 32 psi front, perhaps a bit high, but not enough to make a difference. We checked the rebound, it was a bit slow, so slackened that off 1/2 a turn, - next time out the effect was not so extreme, but still there.

The other mates that i was with thought it to be the way I was riding (like a pussy), - i was not carrying enough corner speed through the 2 main corners (Lydden, so there are only 2 fast corners really), - i was doing my braking before the bend, - and whilst the bike was still leant over feeding in the power from low revs as I rode through the corner, - to me this is how you ride a Duc, - (ok with a bit more bottle on the way in). At first we thought it might be the v(L?)-twin torque ripping at the tyre, - but had a look around the paddock, and it was just me.

So if anybody has any clues of experience I would love to know what is going on, - could it be a sign of a dudd rear shock?

it sounds like the tyre pressure is to high
30 front/30 rear also have you set the suspension up as if it is not set up properly it will just rip the tyre
:sing:

[Edited on 15-6-2003 by scoot]

How strange ,can you give me a little more info on the tyre?

How old is it (the date not how long its been on the bike!)

A little prev history

The pressure of 32 psi when hot seem to low to me. I suspect the tyre had to little air in the extra deflaction has casued it to over heat.

what was your pressure cold (about 29psi!!) seems to low me.

What circut was it?

It really isnt my area trhis need to get someone who knows what there doing.

What did the instructer say on the track day?

Kev

Track day tyre wear
 

29 to 30 psi rear when cold and speed up the rebound. you will also need to chuck the tyre as this is now scrap. If the rebound is to slow, or to quick for that matter it causes the tyre to skip under load, you may not notice this but it manifests itself in a rear tyre that has chunked as you described. :devil:

thanks guys.

The pressures cold were 34 rear, 31 front, which is what I ride them at on the road, I left them at that, and checked them after a session, they were 36 rear 32 front. Track was Lydden, and it was hot yesterday. Lydden is all right handers except one left so the effect is mostly on the right side. The tyre, Michilin Pilot sport was fitted about a week ago, how do you tell when it was manufactured? Wheels are light, - Magnesium Marchesinis if that is of any relevance.

I did not ask the instructor, - I know, duh, but I really was not happy with myself as I was Mr Slow on slow day and was sulking to myself. The ride home from the track has removed most of the chunking effect, but you can still see it is not the usual neat blistering, - I will try and get a picture posted.

My original statement of chunking itself apart is perhaps more dramatic than it is, but it was almost looking like it was cutting into existing rubber and moving it back around the tyre as a lump adding to the profile. This is tough to describe.

I run 30/30 pressures when cold...
 

...your rear pressure seems way high...

Not sure if that was the problem though, but on a hot day, those pressures are bound to increase considerably.....


Tim

I really dont know anything about the bikes or modern tyres but 30/30 seems way to low to me.

I tend to run nearlly all modern bikes 36/42 for road use.

if the tyre was only a week old and its a popular make, which it is , it cant be old.

Tyre pressure does seem high for the track. I run 30/28.

If your shock is set up too hard it will chew the rear tyre up really badly, the same if theres too much weight over the rear tyre, also if the seal is failing (like mine :( ) it will have the same effect, I did the CSS at cadwell and wasnt riding anywhere near the speed I wanted to (loadsa slow riders on unpredictable lines so couldnt pass - 8ft CSS rule) and my rear was tearing up on a damp track!

PS the CSS technician lowered our tyre pressures to 30/32 on the day - maybe your tyres are overheating?

[Edited on 16-6-2003 by DJTera]

NO NO NO DJ, if the shock is set too soft it will chew the rear tyre to much, not if its too hard!

EH? If your shock is too stiff and you hit some bumps etc as your cornering it will chew the tyres up! Your tyre ends up doing more of the suspensions work!

Cold Tear?
 

Ian,
If, as you say, you were not riding as hard as you would on the road then is it possible, even on a hot day, that your tyres were not getting enough heat in them and so trying to power out of bends could cause the tyres to cold tear?

I had the same problem with my R6 doing the roundabout GP's and once I had seen the results of going crackers on a cold tyre I now try and get em warm before playing silly buggers.

The soft rear suspension should not be a problem on a Duke though as they are renowned for being over stiff from standard and the standard spring is too much for your average sized family bear.

Might have been a contributory factor for the R6 though as they are v soft.
Set mine with MH Racins set up for four quid, changed the bike and only needed minor tweaks to sort it for me.

Tyre pressures
 

Dunno about the wear/suspension set up etc but just returned from 2 days at Brands on the European Superbike School. Great training and they also set up my bike.

Tyre pressures 31 front & 30 rear. Rear sag set uo and front prload adjusted. They suggested NOT changing the other settings.

Worked a treat. 207RRs were fantastic but now look very second hand!
:ninja::lol:

DJ stop cahttin ****!!

quiet ya tongue

ducatimad,do you run the same preasures on the road 207rrs 31 fr 30 rear

Despite my avatar (more on that later) I run a 2000 996SPS on track and do "quite" a lot of trackdays. I changed to using slicks last year and haven't looked back since.

The bike received some serious supsension mods earlier this year from JH Performance and the difference is unbelievable. John himself may ride it at Mallory on the 1st so that you can see what it can do (there's no way that I can get near it's limit.)

Regarding the question about tyre wear on track, I'm currently using a soft compound front at 30psi (cold) and a medium rear 29psi and have just completed 4 days: Jerez, Mallory, Cadwell and Snetterton - that's 610 miles and I may be good for another day yet. The last treaded tyres that I used (D208 GP) were excellent but only lasted 210 miles on Silverstones GP circuit!

http://www.dunloptyres.co.uk/site/tyres/4x4/pressureGuide/
 

See the above link.

I run 32 front and 34 rear on the road. Reducing the pressure does get more heat into the tyres and quicker but the trade off is that the tread closes up. They said at the school that 1psi reduction reduces the tread by 50% and therefore the water displacement capabilities - MD of Pirelli agreed (he was there).

I never play with the pressures on the road. One other bit of 'bad' info - apparently, once the tyres reach a high temperature, once they cool and then re-heat they need to heat up to beyond the original point before they provide the same level of grip again. This applies even more to 'race' orientated tyres that are designed to be heated to these levels only once - or so I was told, I'm no expert!:frog:

here\'s the pic
 

I'd go along with weeksy there

The wear in the picture is ok, the tyre is wearing in that arear because that is the contact patch when you are getting on the gas hard. my rennesports show similar wear at the point the tread starts, getting worse as the bike is moving upright. When Paul Young rode my bike there was even wear over the entire tyre. When i asked why he explained that he was spinning the back tyre up progressively from extreme lean angles and the tyre was not digging in and showing this tye of wear.

dave

Looks like mine did except mine was tearing at the edges

chicken strips!! Yeah your're right, thanks guys, - you were supposed to say that Lydden does n't have a right hander where you can get here right over. - The left side does look better but i so much prefer left handers.

The journey home took most of what had built up on the tyre but honest it was n't right, - nobody elses tyre looked like this in the paddock, - it was really uneven wear, - if it does it again on the DSC day you can see first hand, - although i will take some air presure out.

Big loads of respect to anyone who'se prepared to run on those shite Michelins, watch out for the totally unexpected spit off mate, it's only a matter of time !!!.

Earth, sky, earth, sky, ouch, ouch, ouch. where's me wallet.

No decent feedback and seem to go from good grip to zero very quickly.:mad:

thanks Paul!!! Just what i needed that'ill help with my confidence!!

Now if anybody remembers the Michelin A and M48's, - now there was a crap set of tyres, - would wheelspin in a straight line, on a CB750, - would just sudenly notice the revs climbing without any throtle input.

PJ,

Why do think the Michelin man looks like he does wearing a permanently inflated air fence suit???

Once bitten twice shy!!

Ray

Tyre wear is down to pressures, riding style (how ham fisted/brave with the throttle or how smooth you are), weight, track temperature, suspension set up, track surface, etc, they all interact, get em all right on the day and you tyres will grip like glue and will just wear down with no "roughness" and if you name is Valentino Rossi you will have set a new lap record!!
Its might be worth thinking of any rough areas as "distress", unavoidable for the vast majority of riders and even the racing elite take tyres beyond the ideal parameters in the desire to win.

i used michelins on trackday
never again supercorsas all the time know.

as for the pic the tyres fine(except the lines around the edge never seen them before!!!!!!!!!
:sing:

Dunlop 207RR front after 200 miles of brands (done 50 miles after track day on the road)
 

Try again! 207RR front
 

? try the links
 

Front:
http://www.ducatimad.plus.com/images/tyreF.gif

Rear:
http://www.ducatimad.plus.com/images/tyreR.gif

Not much chicken for tea................

Just put my first set of 207RRs on the 996R and straight away the front feels 100% better, never had the feeing that the Michelin was going to hold up and was unfortunately (and expensively) proved right.

There are some great deals to be had out there on 207RRs, you can get a pair fitted to loose wheels for £160.

Not trying to knock your confidence Ian, the tyre has already done that as you've posted here with concerns about it. Is it worth trashing a bike for the sake of a decent pair of tyres ?, I don't think so, speaking from experience.

Saying that I have to agree that the marks you talk about look pretty normal, from your original description I was expecting to see cold shear evidence when you posted the picture later.

Interesting to hear how many others have had the "Michelin Experience" which ends in a trip to the wallet or the hospital or if you're really unlucky to both.

Glad to see that you're enjoying those RR's Paul.

They have completely transformed my M900 since I had them fitted for £99!!!!!!!!!!!!!!!:roll:

similar experience to me
 

Ian

I did a trackday at Mallory last August - in the intermediates, tyres were pilot sport cups 31 and 34psi.

All the right handers had the edge on the other riders - overtaking no probs...(with a good consistant wear to rear tyre)...

...but once I was at the devils elbow (only left hander) the rear end of the bike progressively got worse throughout the day.

The tyre was tearing up on the left to the point where it was sliding coming out of the bend. Had a few people agree it was cold tear - even though there seemed to be loads of heat in the tyre - it wasnt sufficient on the left side.

Part of the problem is my bike has been re-sprocketed with 1 down front 3up on the rear. Great for most situations just not at Mallory.

Regards
Les :-)

ps Have just moved over to rennsports as the rear end was sliding a fair bit on the road (round the twisties) - managed to get 1000miles from the cups :-(

i admit to being raelly confussed about tyres now. I have never been a fan of Michelins but decided to fit this one rather than go for new pair when there was life still in the front, - and as a result of the recent write ups in Bike magazine, - they seem to really rate the Pilots. However I do accept that the way a vee twin puts out it's power is so totaly differnt from an inline 4. - I was cpoming out of the bends on about 7000 rpm where a mate on an R6 was screaming out 12000 rpm.

The picture of the tyre does look different from what was seen after a 20 min track session, - the picture above is after 80 road miles, - It did look like a tear and chunking blobs of rubber at the track, honest.

Any tyre experts coimng to the DSC track day?

my friend was on an SV650 - every lap I would be ready to overtake him until the left hander when he could nail it and leave me standing...whilst i'm gentle on the throttle while the rear is spinning...

Not good for confidence!!! - got slower as the day went on - and the tyre got worse after each session...

We have a professional tyre fitting guy at Mallory on the first, but I don't know him yet, so can't comment on any advice he might give you. The tyre pictured looks perfectly normal with wear at the main part where you put the power down coming out of corners. A lot of the bobbles/marbles that you get at the edge of the tyre are simply rubber coming off the track. After a very hot day at Cadwell and only two other 8 lap races there, my rear is covered in extra rubber and only fit for the bin. The left at Mallory, The Devils Elbow, is a well know high-side point as there are so few lefts that this side of the tyre could stay 'cool' for a whole 20min session. If you're too eager on the cold tyre, it will slip, then grip and you go for a flying lesson. The shredding talked about is just cold tearing.

Glad to hear the 207RR is a good tyre. I have just bought two 'used' sets that have done one R6 Cup race each and although they look a lot more shredded on the right than those in the picture above, they will do me for some time. The left hand side and centre of the tyre still have the mould nipples sticking up.

WeeJohnyB
PS note to self - stop pretending you know anything about what you are talking about, some poor soul mey rely on your ramblings

Ian stop worrying about your tyres mate, the rear pilot sport on my ST4S looked a lot worse than yours after John Hackett had done a session at Silverstone on it. I take it you are using a 190 rear-that will be why you have the chicken strip-change to a 180 mate you will get loads more grip.
Pressure wise you should reduce your back tyre pressure to 30lb ish for track riding.
Don't worry about MR James comments about Michelin, he just doesn't like them. Have to agree though the AM89's were CRAP.

John

thanks Monty, - if it occurs again at Mallory I will come find you all and see what you think. And WJB thanks to you also, - I am a poor sould who does value your input and advice, - now if you could could just get my track day state of mind sorted for me??....

you can get chunks out of the rear if you go too hard before the tyre has had a chance to warm up properly. Make sure you 2 of 3 gentle-ish laps before gunning it. That way the tyre has chance to get upto temperature.

Heres mine after Croft.
BT56SS's were starting to slide at the back when exiting Tower and JimClarke Esses which is odd as they are both right handers and so are 90% of the corners at Croft?









Ran 30 fr and 30 rear.
Warmed em up for a few laps and let em ave it.