Tires changing colors

[Sirref]

So today I went out on a fairly aggressive street ride through my favorite 100mi course of windy back roads. The weather was pretty hot which combined with my riding caused my tires (michelin pilot street radials) to heat up more than they have before. I did my usual look over before and after the ride, there was nothing unusual before but after the front tire was brown in the center line and the rear was brown on the sides. Does anyone have any idea why this would be the case? I haven't seen this before.

@csmith12 @Motofool

[csmith12]

You got the tires crispy!

Naw... for real. There are oils in the rubber of the tire. Depending on many factors (mainly heat), your tires will change color because the heat brings the oils to the surface of the tire. That oil then mixes with whatever your riding on, dust, dirt, ect.. ect..

They turn blue (clean pavement) most of the time but I have seen other colors, even RED!!!!.

And one of the other things about phat man tires (michelin's). They show their wear beautifully, by wear and by color. Color is an indication of a heat cycle. Normally, too many heat cycles is considered a bad thing.

[Sirref]

oh ok, so basically I was using the tires at or near their optimal temp then?

[Singh2jz]

Originally Posted by csmith12

You got the tires crispy!

Naw... for real. There are oils in the rubber of the tire. Depending on many factors (mainly heat), your tires will change color because the heat brings the oils to the surface of the tire. That oil then mixes with whatever your riding on, dust, dirt, ect.. ect..

They turn blue (clean pavement) most of the time but I have seen other colors, even RED!!!!.

And one of the other things about phat man tires (michelin's). They show their wear beautifully, by wear and by color. Color is an indication of a heat cycle. Normally, to many heat cycles is considered a bad thing.

So you're saying the tires can turn blue whenever you ride em hard on clean pavement?

[csmith12]

Originally Posted by Singh2jz

So you're saying the tires can turn blue whenever you ride em hard on clean pavement?

8 minute response, lol WOOT! My first achievement!

Riding hard is relative to the rider. Is one's hard riding enough to blue a tire, not always but in my experience, the oils in commonly used tires will make the color blue when reacting to clean pavement and air. Some tires are made with more oils and are more likely to react with a blue hue. There is a simple fix for it though, just take it for a ride at a slower pace and it will turn just as black as it always was.

[Rifleman]

Yes, it was defo heat.

I would say that the really high performance tires turn blue, or even iridescent purple.

so you got the tires up to or just over their normal operating temps...

Street tires are different then track tires in how fast they can shed heat. track tires are thin and dump heat fast because they are constantly being pushed and getting hot... street tires are thicker and will hold a bit more heat because some times we are sitting at a light or what have you and the tire shouldn't cool all the way down.

if you keep pushing them, the tire will feel "greasy", sharp inputs start to get mushy or soft. Going knee down left to knee down right won't feel as firm and sharp...

that's the time to back down a bit, that's the first warning you will get.

frequently the only warning you will get.

[Singh2jz]

Originally Posted by csmith12

8 minute response, lol WOOT! My first achievement!

Riding hard is relative to the rider. Is one's hard riding enough to blue a tire, not always but in my experience, the oils in commonly used tires will make the color blue when reacting to clean pavement and air. Some tires are made with more oils and are more likely to react with a blue hue. There is a simple fix for it though, just take it for a ride at a slower pace and it will turn just as black as it always was.

8 minutes and 1 sec is max for that achievement lol. There was some quality info in there as well so that's fast for that much.

Well, I understand that it would go back to black, but it was just the colors corresponding to different things that boggled my mind.

[alex.s]

my tires turn blue all the time. never had em turn brown. maybe you ran over some ****

[csmith12]

Originally Posted by Sirref

oh ok, so basically I was using the tires at or near their optimal temp then?

Take this with a grain of salt... because I don't know everything.

Did you ride them at "optimal" temps? No, imho they overheated. This could be for multiple reasons but the most common is underinflation. I will ride a tire that has blued a few times without much worry, but after a few more times... the tires start to feel different to me. Null and dry if you will and more likely to give me negative feedback (chatter). YMMV ijs...

[Sirref]

Ok, I'll double check the psi tomorrow morning when I head to work. I've been running 30f/32r as my standard temps and have been double checking them about once or twice a month.

[DaBlue1]

Originally Posted by Sirref

So today I went out on a fairly aggressive street ride through my favorite 100mi course of windy back roads. The weather was pretty hot
...after the front tire was brown in the center line and the rear was brown on the sides. Does anyone have any idea why this would be the case? I haven't seen this before.

Originally Posted by csmith12

You got the tires crispy!

.......There are oils in the rubber of the tire. Depending on many factors (mainly heat), your tires will change color because the heat brings the oils to the surface of the tire. That oil then mixes with whatever your riding on, dust, dirt, ect.. ect..

What cssmith says about the natural oil in the rubber is true. Tires do tend to turn brown. It's called browning or "blooming". There's a chemical tire manufactures use called Antiozonant. It helps prevent rubber degradation (cracking, splitting, oxidizing, and overall deterioration) due to the rubber’s interaction with ozone. The tire rubber is designed to constantly work the antiozonant to the outside of the tire as it rolls – in this way, the outside surface of the tire is continually replenished with fresh antiozonant. It's not necessarily heat. Tires will brown in cold weather too.

The negative result of having antioznants on the tire is tire browning – once the antiozonant gets exposed to the ozone in the air, it turns brown due to oxidation. Combine that with brake dust, road grime and dirt, you get a brown tire.

Want to age a tire prematurely, have it with cracked sidewalls? Leave it dirty and coated with metal flakes so that the rubber can't "breathe" and dry out.

Did you really get your tire that hot to turn your tire brown with a little aggressive street riding in low 90 degree weather? Probably not.

Do you clean your tires regularly?

Just simply cleaning the tire and buffing it with a clean rag can bring the natural black luster back to the tire.

Will all the brown come off? Maybe, maybe not. It will depend on the tire.

[Sirref]

I clean my tires when I spray down my bike which is once every other week or so. I just do a quick spray w/a hose and wipe the bike down to dry it off then clean & lube the chain (I do that once per week on average)

I did ride through a few rainstorms since I've cleaned the bike though if that makes a difference.

The tires were pretty damned hot though, we're talking can barely touch it with a bare hand hot. It's also gone back to normal already.

[DaBlue1]

Originally Posted by Sirref

I clean my tires when I spray down my bike which is once every other week or so. I just do a quick spray w/a hose and wipe the bike down to dry it off then clean & lube the chain (I do that once per week on average)

I did ride through a few rainstorms since I've cleaned the bike though if that makes a difference.

The tires were pretty damned hot though, we're talking can barely touch it with a bare hand hot. It's also gone back to normal already.

Water alone will not remove baked on dirt. It's kind of like patting your ass dry after a good dump. Over time sh** gets caked up and needs a good wipe.

Tires get hot and they cool down quickly, but trust me, you were in no danger of shredding a tire due to heat related stresses. Your tire is designed for 130 mph. I think at that point you'd want to start worrying about heat.

[Sirref]

Alright, so I checked the psi and it was at 30f/32r I upped it to 32f/36r while I was at it since that was the recommended psi in another thread on these tires.

Good to know, so basically in the future wipe the tires down with something like this?

[DaBlue1]

Originally Posted by Sirref

....Good to know, so basically in the future wipe the tires down with something like this?

It doesn't even need to be that abrasive, unless it's really bad, but yeah that works with a little mild detergent.

[csmith12]

Originally Posted by DaBlue1

Water alone will not remove baked on dirt. It's kind of like patting your ass dry after a good dump. Over time sh** gets caked up and needs a good wipe.

Tires get hot and they cool down quickly, but trust me, you were in no danger of shredding a tire due to heat related stresses. Your tire is designed for 130 mph. I think at that point you'd want to start worrying about heat.

hmmmm.... I think there is more to it than speed alone.

Q2's, speed rating of W - (168mph) My r6 will not go that fast, yet still turned blue.
Rosso 2 rear, H rated - (130mph) My 250 will not go that fast, yet still turned blue.

[Sirref]

I'd wager that acceleration is more of a factor than raw speed on the rear and braking is more of a factor on the front since only the center of the front and the sides of the rear changed and those were the points where I was hardest on the brakes/throttle respectively

[adouglas]

Tires changing colors?

In my day, that was due to this stuff called "acid."

They were just as likely to turn paisley.

[DaBlue1]

Originally Posted by csmith12

hmmmm.... I think there is more to it than speed alone.

Of course there is. Different tire compounds will react differently due to heat. They make tires that produce different color smoke during a burn out.
However I think you may have missed my point.....

Originally Posted by DaBlue1

.....you were in no danger of shredding a tire due to heat related stresses. Your tire is designed for 130 mph. I think at that point you'd want to start worrying about heat.

[csmith12]

Originally Posted by DaBlue1

Of course there is. Different tire compounds will react differently due to heat. They make tires that produce different color smoke during a burn out.
However I think you may have missed my point.....

I get what you're saying, I am a pro at reading between the lines.

I didn't miss the point though, I am just worried about the impression your comment gives to those who know no better. In the end, if your tires are turning colors, that's is a clue. For better or worse... it's a message the bike is telling you.

Originally Posted by Rifleman

Yes, it was defo heat.

I would say that the really high performance tires turn blue, or even iridescent purple.

so you got the tires up to or just over their normal operating temps...

Street tires are different then track tires in how fast they can shed heat. track tires are thin and dump heat fast because they are constantly being pushed and getting hot... street tires are thicker and will hold a bit more heat because some times we are sitting at a light or what have you and the tire shouldn't cool all the way down.

if you keep pushing them, the tire will feel "greasy", sharp inputs start to get mushy or soft. Going knee down left to knee down right won't feel as firm and sharp...

that's the time to back down a bit, that's the first warning you will get.

frequently the only warning you will get.

Real talk.... yes!

[DaBlue1]

There are more than a few threads on here about tires and suspensions that can keep anyone looking for info busy for a while.

One in particular- https://www.ninjette.org/forums/show...oss#post682629

The Race Track Tyre Wear Guide

[Motofool]

Originally Posted by Sirref

.........The tires were pretty damned hot though, we're talking can barely touch it with a bare hand hot. It's also gone back to normal already.

Street tires should not get that hot; you should be able to keep your hand on it after a long ride.

IMHO, it is all about keeping the proper pressure for the conditions.

Why is pressure such a key factor?
Because pressure determines how much the carcase bends and gets deformed under the weight and the dynamic forces.

That excessive surface temperature comes from the extra energy that the engine wasted just to be stored in the rubber.
Internal friction of the carcase generated more heat than what could be transferred to the air; hence, the temperature increased until a new heat transfer balance was reached.

Regardless the changes in color, that waste of energy is not good for your pocket or for the health of your tires.

The designer of any tire determines by experimentation, what is the best balance among footprint of the contact patch, the spring effect, traction and temperature.
For any specific compound and carcase structure, pressure is all he changes in those experiments.
A pressure that covers the most different conditions is recommended in the manual (just as a starting point).

Adjust your cold pressures to the task: pump it up some for heavy load, high speeds and/or hot weather.
Make a habit of touching the side of your tires with your bare hands each time that you dismount after some good miles.

Too cold is telling you that your cold pressure is higher than ideal and that you are sacrificing suspension effect and traction for saving fuel.

Too hot is telling you that your cold pressure is lower than ideal and that you are sacrificing fuel saving and tire life for practically no reason (extra suspension effect and traction due to initial low pressure soon disappears due to excessive hot pressure ............ or so I believe).
Yes, all that extra flexing and heating of rubber is like pumping more air into the tire, as hot gas = high P = high volume = high air viscosity.

You could also use the 10/20% rule:
http://www.mad-ducati.com/Articles/TirePressure.html

[Sirref]

I'll do that test next time I go on an aggressive ride with the bike, I bumped the psi up by 4 in the rear and 2 in the front to 32f/36r so that should make a bit of a difference

[rojoracing53]

colors are not a problem and I really doubt your overheating the tires while riding on the street no matter how fast you ride. I've blued rosso II's on the street and at the track and I know the tires are way hotter while on the track by at least 50 degs.

[Sirref]

Originally Posted by rojoracing53

colors are not a problem and I really doubt your overheating the tires while riding on the street no matter how fast you ride. I've blued rosso II's on the street and at the track and I know the tires are way hotter while on the track by at least 50 degs.

I don't feel that I have heated the tires beyond their operational temp. I just found it the color change odd and thought maybe the heat had something to do with it, since they were hotter than I have ever gotten a tire to before, which seems to be the case.

[Motofool]

Originally Posted by Sirref

I'll do that test next time I go on an aggressive ride with the bike, I bumped the psi up by 4 in the rear and 2 in the front to 32f/36r so that should make a bit of a difference

Yes, that will help, ........... although it may not be enough.
For example: Rough pavement at noon time increases the tire's temperature some more.

2/30 = 6%
4/32 = 12%

When you ride fast, more times per second any same area of the tire is bent (if tires were rigid, like a train's steel wheel, they would stay cool).
Yes, it is exposed to a faster cooling airstream, but it seems that heating over-rules cooling.

When you corner fast, the lateral deformation of the carcase is more pronounced while it supports a bike that becomes up to 40% "heavier" (combined centripetal force + weight) than when rolling straight.

Copied from:
http://sportbike.natkd.com/tires.htm

"Tires and Heat

All tires have an optimum operating temperature. When they reach it the rubber compound is at its stickiest, and the carcass at it's most flexible. Below that temperature, grip is reduced and the tire may have a tendency to slide.

If the tire exceeds its optimum operating temperature things go wrong quickly. Excess heat causes the tire tread to degrade. As the adhesives used to bind the tread compound to percolate to the surface, the tire become very slippery. In severe cases the tire will actually shed chunks of tread.

To reduce heat buildup generated by flex modern tires are built of thin strong plies. Since the carcass runs cooler a softer compound can be used.
......
It should be a habit to look at your tires as you approach your motorcycle. Observe the tires for any indication of low air pressure and the condition of the tread surface.

A cheap tire pressure gauge is better than none. Check your tire's air pressure often, if you ride once a-week, do it before you start out. Always check the tire pressure while the tires are cool and follow the tire manufacturer specifications.

Try not to add air to an already hot tire. The air in the tire expands as the tire heats up. Adding air to an already hot tire will over-inflate it. And cause excessive wear in the center of the tire. Tires low on air will run at higher temperatures which can deteriorate the tire's compounds and reduce the tires life; besides degrading your motorcycle's handling. Running tires low on air will cause the outside edges to wear. Tires are not cheap, keeping them properly inflated will make them work better, handle safely and last their intended life. "

[crazymadbastard]

Originally Posted by alex.s

my tires turn blue all the time. never had em turn brown. maybe you ran over some ****

Wrong, drove too fast and scared the tires, they shat themselves.

[CycleCam303]

Also if you're going to be going HAM in the streets look up the track tire pressures for your Pirellis. I believe it's 28 in the front and 32 in the rear. Don't quote me on that. You drop the pressure because the tire psi will jump up quite a bit with hard braking and acceleration. The tires for the little bikes have different construction making them not quite as rigid. So they will heat up quickly like a big bike will. The track psi setting for my duc on supercorsa 2s is 28 30. Mind you my bike doesn't spin up the rear but makes 120 rwhp.

So don't go inflating them super high thinking that will help.

[JohnnyBravo]

I want some hi-po lime green tires, shame they ain't high performance

[Ytse Frobozz]

Fact: when the tires turn blue, your beer is ice cold.

[Sirref]

Originally Posted by JohnnyBravo

I want some hi-po lime green tires, shame they ain't high performance

I'm likely going to get one of them green chains when I replace my chain (probably around the 10kmi mark (as a treat for the bike) so this summer)

also very relevant link I'm likely going to be getting this this summer too
http://www.tirepenz.com/product_p/refkit-green.htm

[JohnnyBravo]

Originally Posted by Sirref

I'm likely going to get one of them green chains when I replace my chain (probably around the 10kmi mark (as a treat for the bike) so this summer)

also very relevant link I'm likely going to be getting this this summer too
http://www.tirepenz.com/product_p/refkit-green.htm

Yea saw the tire penz... I'd rather just get paint markerz

Green chainz? I don't clean my chain enough to have a fancy one :/

[Sirref]

Originally Posted by JohnnyBravo

Yea saw the tire penz... I'd rather just get paint markerz

Green chainz?

a tad bit pricey but I don't trust cheap things with my life so I was looking just under this price point anyway.

http://www.motorcycle-superstore.com...T.ac=SLIsearch

My bike is going to look sick when I repaint the fairings and replace the right side fairing from my lowside. Black/Green will have never looked so good.

[JohnnyBravo]

Looks good in the pic! Hmmmm wonder how much a gold one would help my lack o chain cleaning?

[Sirref]

Originally Posted by JohnnyBravo

Looks good in the pic! Hmmmm wonder how much a gold one would help my lack o chain cleaning?

A rear stand would fix mine. I did it religiously until last winter hit where I'd have had to clean it every day to keep it clean and fell out of the habit.

[csmith12]

Originally Posted by JohnnyBravo

Looks good in the pic! Hmmmm wonder how much a gold one would help my lack o chain cleaning?

Mr. T pity's da fool who don't clean gold chains.

[nickjpass]

My tires are always brown because the roads near my home are dirty, and I have a gravel driveway. I feel like it 'stains' them. Once I go riding, especially on a spirited ride, they clean themselves lol

[JohnnyBravo]

So if you buy Scott's oiler you never have to clean a chain again

[rojoracing53]

Originally Posted by JohnnyBravo

So if you buy Scott's oiler you never have to clean a chain again

I've got about 5000 miles or so with my Scott's oiler and yeah my chain never gets anywhere near as dirty as it used to with normal chain line use. Just out of habbit I've taken a dry rag and wiped it down and it comes out looking perfectly gold with no effort at all. It not even blackend to begin with, it's just a little dark. I mostly only wipe it down to inspect that everything is still getting even oil.

[JohnnyBravo]

Thanks Rojo
Folks always say my chains way to dirty, apparently not dirty enough they feel the need to clean it though