Can the rubber's age affect it at all if they're only 24 months old.

:thanks:

Yes, it can - the continuous heat cycling and the environmental degradation makes the tire compound get harder over time. I've gotten rid of every set of my PS2s (four sets in 3.5 years) because they had heat-cycled out, long before all the tread had been used.

brad

 

Exactly; I've got a spare set of PS2's in the basement I could use on the street but for track use they're pretty much done after 1.5 seasons for DE use. IIRC, there are tools to test the durameter of the tire in order to judge how hard they've gotten.

When I took these off the track wheels, I replaced them with the PS2's that came with the car to get me through the season--big mistake. After 1 DE, they had less traction than the dedicated track tires. My guess is that the roughly 2 years worth of street use put enough heat cycles into them to essentially render them useless for track duty. Still had plenty of tread..

 

Yes, they do. It depends mostly on age, heat cycles and wear depth.

However you can "shave" brand new tires and get the best grip there is on dry surface = slick.

 

People shave PS2's? You might as well with a street alignment because the edges cord through way before the tread. (if you are dedicating them as track tires.)

People shave PS2's? Hmmm....really?

 

Wow, I never knew street tires would heat cycle. That's nuts.

 

What do you consider a heat cycle?

 

Heat cycles aside - my PS2s wore out the outer edges. That's where I've noticed the loss of performance. That's after 7 track days.

 

Bizarrely, same happened to me. I never thought I'd have heat cycled my tires, with no track or auto-x so far, just a bit of spirit here and there. My rears had decent tread at 2.5 years and 17,500 miles, perhaps 5/32nds but very even, decent wear. I was waiting for them to get to 4/32nds, but I got tired of the car feeling so loose in the dry. So, on went a new pair of rears and yes I have rear grip again.

I wonder if this is a PS2 issue. I've also noticed that PS2's are more temperature sensitive than pretty much any other summer performance tire I've tried.

 

I was waiting for them to get to 4/32nds, but I got tired of the car feeling so loose in the dry. So, on went a new pair of rears and yes I have rear grip again.

I was out and about town today in 20c weather and the rear of my car was slipping sideaway in 1st gear during relatively slow speed turns with modest throttle application. I felt a little embarrassed to have the rear step out exiting a Starbuck's parking lot.

:hilarious:

 

Maybe I should switch to Contis for my next set. Do they heat cycle as much?

 

I'm not convinced that street tires heat-cycle out on track like R-comps and race slicks, but the rubber certainly deteriorates and hardens over time. I think of this effect as weathering (temperature swings, sun, rain, etc.) rather than heat-cycling.

I must be at the other end of the continuum from beez (4 sets of PS2s in 3.5 years), as I just ditched my OEM PS2s for a new set of RE-11s after 3.5 years. Yes, they had become noticeably less grippy than they were a year or so ago, but the rears were down to the wear bars anyway.

There was/is an old rumor to the effect that high performance summer tires are constructed with a harder compound near the wear bars, so they will wear slower toward the end. That was supposedly justified as a "safety" feature, but, if so, I guess sliding around more in the rain wasn't considered. The sidewall rubber seems to harden over time as well, which seems consistent with the time-in-service and weathering explanation.

 

It will be interesting to see how my RE-11s compare to the PS2s over time, since I don't use the street tires as much as I used to...

brad

 

My rear PS2s would always lose traction when they got near the wear bars. I drive 15K miles a year which is about how many miles I get from my rear tires.

 

Confirming new tyres have a lot more grip.

 

Fascinating thread all. I just replaced my PS2s with RE-11s, primarily because I wanted to get two DE run days on 'sticky' tires before the snow falls, and am very excited to try them out on the track.

The outer edges of the PS2s were fairly worn on the fronts, although all four still had a little tread above the bars. Once the tires were off, I took a good look at them with the Porsche mechanic and at first glance I felt like I may have pulled the trigger on the PS2s a little early. He pointed out that all of the tires had small cracks running in between the tread grooves (weathering?). They also were very loud when driving and seemed overly firm (I bought the car used and the tread was about half gone at that time, so I didn't know how new tires would be). They were not too bad on the track after letting out a proper amount of air.

I've only got about 20 miles on the RE-11s, and my mechanic said that the chemical used to help release the tires from the mold would need to wear off before the tires would get sticky. My first attempt going around a corner fast did not go too well (not sure what happened, but it didn't hold the corner). They also don't seem as responsive as the PS2s, but again, only 20 miles so far.

Any thoughts?

 

If the surface is not shinny anymore then you are good to go.
Now the trick is for the R specs to work correctly you must first get them HOT. Dont expect too much if they are warm or cold. Also different brand tyres will have different characteristics at different temperatures in this respect.

 

I am not an expert, but I have been told you need at least 50 miles to wear through the mold release.

 

Thanks. Yea, the mechanic who installed them said 50 miles, but I read on another thread that it was 500 miles! I'd better get busy driving - the DE is less than three weeks away!:drivingskid:

 

It will be interesting to see how my RE-11s compare to the PS2s over time, since I don't use the street tires as much as I used to...

Brad, My experience with the RE-11's has been good for the one 3 day weekend I put on them at Putnam Park. I'll be at Mid-Ohio in mid October for another event. With that one track weekend and 4000 street miles the only thing I see is what we used to call the 'groove of doom'. I'll try to get a photo if this term is not familiar.

 

Is this worn out? It's got 3 years on it 55,000 kilometers. No track.

 

They seem to have 2 or 3 mm to go before wearing down to the wear bars, so not "worn out" in that respect anyway. If he used them to AX, Beez might have replaced them by now on the basis of age and weathering. If they are fronts, and I needed to get new rears, I wouldn't hesitate to get 4 new tires in this case. You've certainly gotten good mileage out of them.

 

My first time I took my '06 CS to Streets of Willow (3.5 yr old Michelin PS2's), the handling was terrible. The same curves that I drove with my old Lotus Elise were extremely disappointing with the CS. I wondered if I made a bad decision to trade in my Elise for the CS! It was sliding in every curve.
I drove my wife's '07 CS (newer Bridgestones RE050's and Tipronic), the handling was tremendously better! I KNEW the tires were a major problem!

The PS2's at 15,000 miles have plenty of tread but NO GRIP!!! Maybe the 3.5 yr old PS2's have been hardened and heat-cycled out. What do you think?

I'm going to order RE-11's as soon as my budget stabilized!!

--Hal

 

BRIDGESTONE RE-11 installed.
I took the CS though the same Westlake Hairpins (Southern Calif people know where theses are), comparing my replaced PS-2's..

Pulling through the curves made me a BELIEVER!
"Do tires lose traction as they wear down?"
Uhhh...YEAH!!! THEY DO!! BIG TIME!!
The new RE-11's made me a believer.
The 4-year old PS-2 Michelins with 14,000 mile (AND plenty of tread) had lost all their GRIP! WOW! Not a subtle difference. A MAJOR DIFFERENCE!

Next?? Streets of Willow here I come!

--Hal