less grip as the re050's wear out?
 

i know this sounds like a thread for the tires & wheels section, but i'm posting it here for people who have experienced this on the track.

my stock re050's in the back are getting pretty worn out (maybe 2mm tread depth left) and it seems like there's less grip than when they were new. this is contrary to what some guys on trackhq have reported for other tires. they say that their tires pretty much retain the same amount of grip until the treads are completely gone (and advocate driving them until they're completely bald).

is it my imagination that my re050's are less grippy or does anyone else have the same experience? i was going to do one more event on them, but i dont want to get out on track and then find that i have no grip left. :confused:

Many events won't let you on track with such little tread (your tires are 'dead'). I too once thought that at least dry traction would improve as the tires become bald. However, some guys on here pointed out that the heat cycling of the tire over its life leads to decreased traction by the time you get to the bald point. Perhaps someone else will chime in further.

Get new tires before your next event!

Heat cycling often kills tires before they wear out, but this is under racing conditions. Anything short of Tail of the Dragon on the street typically wont put enough heat into the tire to be counted as a heat cycle.

What kind of driving have you been doing?

+1.

i've been doing at least one track day and/ or auto-x a month. i've had 5 events so far since i bought the car in september. i use the car for daily driving also of course.

i didnt realize heat cycling would be an issue on these tires after only 5 events. my hankooks used to take way more cycles. the absolute worst tire when it comes to heat cycling are the rt-615's. i'd get maybe 3 events on them before they become completely useless. i call them "plasticized". :rofl2:

Yep, but for each track day you probably had 4 sessions with a long break in between, this multiplies the heat cycles. At auto-x you typically get 2 heat cycles, morning runs, and afternoon runs (or something to that effect). As you noticed the number of heat cycles varies dramatically by tire, but most of the 140TW Bridgestones seem to be good for around 25 and then start to fall off.

Some drivers also swear that age makes a difference, and that they can tell the difference in performance of a new tire that is 1 year old vs a new tire that is fresh out of the factory. This is supposedly because of some of the oils required for playability are leaving the tire. I don't think I'm that good, but I do like the smell of fresh rubber!

It's true that heat cycling can cause a tire to cure and harden, causing a loss of grip. However this is mostly limited to R-comps. Most street tires, and I'm talking 140 treadwear and up, are able to hold up to nearly infinite heat cycles and are just as fast new as they are on the cords.

That being said I have noticed a lose of grip as my stockers wear but I'm attributing that more to it being much colder then when I had them new.

There is something about the RE050 that causes them to lose alot of their grip once they get down the wear bars. For reference, I bought my Z in December, the grip of the tires was best in the spring, by summer I was down the 2/32 and the grip just wasn't there anymore. That was after a few auto-xes, some drag racing, and I'm pretty hard on tires on the street. As much as I like Bridgestone, i think this is one of their worst performance tires.

i'll just get a fresh set and bring them to the track with me. i'll run 2 sessions on the old and 2 on the new and know for sure. i'll keep you guys updated. i wouldnt be surprised if in fact, there's less grip now than when they were new.

I can't speak for the RE050s, but the RE070s that come stock on the STi usually have a decent life, but as you get past that main-bulk area of tread and down near the wear bars you will start to get to that inner compound that is much harder and less grippy than the softer outer layers.

A great tire if it's available for the Z is the Dunlop D1 Star Spec tires. I've put about 25k miles on a set on my LGT and did about 20 track days before they had to be retired.

Price on the Dunlops is also GREAT.

-mike

Dunlops are awesome, I had them on my old car. Unfortunately they only go up to 18" sizes.

I also had the Star Spec's, great tire, just not available in larger sizes.