Opinion: Prudent or Wasteful Rear Tire Replacement

[stangmx13]

Race tires today are fucking amazing. The heat cycle count is so much higher now than even 8 years ago. I've got a set of slicks with over 1000 miles on them that I will run some more at an A pace. If you really experience front end push or the tire spinning up a lot, replace them. Tires last a lot longer than you think.

i did that w/ a UK Dunlop rear, ran it on the street w/ the intention of replacing it before the next trackday. but my next set of tires didnt come through, so it got 700mi and went back to Buttonwillow. i was surprised by the level of grip it had once i got it hot (no warmers). still went faster, .

its all a matter of how much grip u actually need. im a lot faster now than i was back then, so id absolutely hate running a takeoff w/ street miles on it. but back then, i was plenty content w/ the amount of grip it provided after ~30 heat cycles.

Minor thread jack 'cause I want to know:

Wear indicators are there as a reference for tread depth not rubber quality, yes?

Is traction enhanced with a treaded tire on the track?

Assuming the rubber chemistry remains constant throughout the dire depth so adhesion isn't affected as the tire wears, what benefit does tread provide on the track? After all, slicks are ,well, slick.

a tire with tread will run hotter. the tread blocks move around and that deformation of the rubber generates heat. this is the main reason why people find that slicks last longer. the slick has a more constant temperature throughout its life, only getting slightly cooler as the rubber gets thinner. the DOT will also cool that amount due to the rubber getting thinner, but itll run cooler even faster as the tread blocks get shorter and that deformation decreases. a cooler tire can have less grip, so it may get replaced sooner.

 

[afm199]

Minor thread jack 'cause I want to know:

Wear indicators are there as a reference for tread depth not rubber quality, yes?

Is traction enhanced with a treaded tire on the track?

Assuming the rubber chemistry remains constant throughout the dire depth so adhesion isn't affected as the tire wears, what benefit does tread provide on the track? After all, slicks are ,well, slick.

It's primarily because race organizations have some variety of production/supersport classes where the tires have to be DOT labeled. So we have DOT race tires, which are pretty much cut slicks.

 

[stan23]

I swear, you could post a picture of a brand new tire with the sheen rubbed off, ask this question, and someone would still say that a replacement is necessary.

If it was the rainy season, there may be an argument for replacement, but not when its still summer.

That said, the criteria for replacement should not be tread. It should be how the bike feels when riding it. If turn-in and handling are impacted or you're suffering from significant loss of grip/performance, then replace. Otherwise run them till they are bald.

I'd be more conservative with fronts than rears but that's just me.

For the track the last thing you want is to go there are have the safety guys reject your tires. Buy ones for the track keep these for street.

I'm probably a lot more cautious when it comes to tires than the average rider, but usually when in doubt, i'll swap. Doesn't sound like the OP has convinced himself that the tire is good to go, so rolling out there with a 'questionable' tire in his mind may mess with him a little bit.

I remember one time, about an hour before a race. A faster guy in my class came up to me and asked if I was really going to do the next race on that rear tire. I was, but I went ahead and changed it anyways. haha

/im sure he was messing with me.

 

[redtail]

Race tires today are fucking amazing. The heat cycle count is so much higher now than even 8 years ago.

Hmm, good to know, I'm still in the habit of new tires only for track days.

 

[Reli]

Um you can't tell it's "done" just from a pic, with no knowledge of how many cycles or days it's been used, much less what kind of tire it is, whether heat warmers were used, or how fast the rider is.

As for using race takoffs on the street, yes it's quite common among intelligent people like myself who aren't anal-retentive about everything. You aren't going to push it hard enough on the street to where the reduced grip is going to make much difference, especially if you're just commuting, in dry weather to boot. Hell I've even taken tires down to when the cords start showing. They aren't going to fucking explode. The grip and ride quality merely reduces.

I don't think any of you are high-rollers, so you shouldn't be wasting your money unnecessarily. This topic is kinda like the guys who insist on 3000 mile oil changes for their car even though it produces no tangible benefit over 7,500 changes.

 

[stangmx13]

I remember one time, about an hour before a race. A faster guy in my class came up to me and asked if I was really going to do the next race on that rear tire. I was, but I went ahead and changed it anyways. haha

/im sure he was messing with me.

hehe awesome. i tend to race on tires longer than most and i always get this kind of shit. "but what about the heat cycles", "u wont go as fast", "i cant believe u dont race on new tires", blah blah blah. i lose at most 0.5s per lap over 8 races on one set and spend much less $$ than them on my tire bill.

Hmm, good to know, I'm still in the habit of new tires only for track days.

ya, this def wasting money. if your setup is good or you arent going very fast, 3-4 days is very possible on most bikes. even if u r fast, u then should have the skills to recognize when a tire is losing grip and ride accordingly. just imagine how many more trackdays u could do a year if u ran one set for 2 or 3 days .

 

[Reli]

hehe awesome. i tend to race on tires longer than most and i always get this kind of shit. "but what about the heat cycles", "u wont go as fast", "i cant believe u dont race on new tires", blah blah blah. i lose at most 0.5s per lap over 8 races on one set and spend much less $$ than them on my tire bill.

 

[ZCrow]

Screw the wear bars...what's up with the developing rip just above the wear bar. Retire for street use.

I have to admit I had not noticed that.

Ahh, then you probable weren't aren't around when Helimot was selling "Poser Pucks" (circa 1996), one could purchase pre-scrubbed knee pucks in your choice of roads the pucks were used on, Hwy 130, Hwy 9 etc.

Triple

I was around, just riding lone wolf and definitely was not in the community so I would have had no clue that this was going on.

These lasted you 2 track days?

No, the rear is 4 track days plus street. I replaced the front before my first B Class with Z2, so it has 2 track days on it.

 

[tuxumino]

if you're going to run C group then the tire is fine, if you're going to run B group then replace it.

 

[Wormwood]

Visual tells me it's getting time, feel tells me it's time. I want every friggin $$ worth of rubber out of that half wore out overpriced round thing.

Just my experience.

 

[HeatXfer]

a tire with tread will run hotter. the tread blocks move around and that deformation of the rubber generates heat. this is the main reason why people find that slicks last longer. the slick has a more constant temperature throughout its life, only getting slightly cooler as the rubber gets thinner. the DOT will also cool that amount due to the rubber getting thinner, but itll run cooler even faster as the tread blocks get shorter and that deformation decreases. a cooler tire can have less grip, so it may get replaced sooner.

It's primarily because race organizations have some variety of production/supersport classes where the tires have to be DOT labeled. So we have DOT race tires, which are pretty much cut slicks.

Thanks guys: you covered both the mechanical and the regulatory!

 

[Falsus Nomen]

Thanks guys: you covered both the mechanical and the regulatory!

Covered it.

For the thread starter, what do you run, street and track on the striple.

 

[ZCrow]

I do everything but sleep with my Striple.

This Monday will be my 6th track day since May. I realize doing everything with one bike is not ideal. I am shooting for a second track/super sport dedicated bike early next year but for I am monogamous for now. Aside from convenience that is also why I have been sticking to Sonoma Raceway because it equalizes the HP advantage and reminds me of GP Saratoga. I suppose it also keeps me from getting a wild hair up my butt.