You mean the part that's touching the pavement gets the hottest? No wonder S20s went all nutzy on me.

Green, you're just blowing smoke up everyone's skirt on this one brutha. That kind of tire is for track only! they could engineer a tire specific to any track. The only thing we need on the street is a tire that wears well in the middle but if they make that, they will sell less tires.

well...yeah...course it's more intense and critical on a gp tire.but i thought it was interesting to find out that'overheating' a tire actually causes a loss of performance and tread life.that i didn't know.like underinflating and such.

'The only thing we need on the street is a tire that wears well in the middle but if they make that, they will sell less tires'....not so fast.if we commit to riding 50 mph,they'd be fine and last forever!so they DO actually make em.

it seems from reading past posts about tires here..a majority automatically lower the recommended psi's,for handling.They're designed to be filled as the manual(or mfg) says.but how many actually do that?

* Last updated by: Grn14 on 3/14/2017 @ 9:32 AM *

They're designed to be filled as the manual(or mfg) says.but how many actually do that?

That's not correct. It states maximum cold tire pressure at 44psi. Being the
tires "maximum load" capabilities and still being able to keep the tire from over heating.

Correct tire pressure is about getting the correct amount of heat in the tire which
can be measured by the fluctuation in psi from cold to hot.

my manual says 41 psi...front and rear.cold.course each mfg has their own particular psi...to make the most out of their tires.don't know where you got 44 cold?for the zx14.

Was off the top of my head. Ok, 41 psi

each mfg has their own particular psi...to make the most out of their tires

Sorry, that's just wrong.

41 psi max cold is the maximum load capability for the tire, not necessarily the best psi to
run the tire at.

Most of the time I go with 45 psi and they still wear out in a season or not much more. I don;t think it matters a great deal to me yet most of the time but when I;m going to go out and ride my hardest I go with 25 psi front and rear. A little extra insurance. It works good for the Pirellis I've used but some other tires just felt squishy and weird. I am a believer that a major component in low tire pressure is the fact that you can keep it hot enough to actually INCREASE the internal pressure by heat expansion. You start off with 25 psi and if you can keep your speed up and corner constantly, that actually turns into 35 psi. Go with 42 psi and you end up with a tire that is way too hard and slips all over if you can maintain speed and cornering action. I can't do it on the street. There's nowhere I can go my fastest more than 20- 30 seconds at a time.

'Sorry, that's just wrong'....okay,well,tell me then.if a mfg creates a tire with particular characteristics,and designed to run on say,the zx14 with it's basic weight,and telling the customer through specs and such that at 'this' psi,you can expect thus and thus mileage and performance from it'...isn't that how they design and sell tires.to any particular rider?or am i way off base here.i mean,i think almost anyone who rides actively kinda knows if their tires are wearing like they should.right?so purposely lowering or raising the psi is gonna result in either good mileage and performance,or it's not.i'm definitely not arguing your statement...just curious how you come to that conclusion. otherwise,what would be the point of getting say,a high mileage tire compound,lower the psi from the recommended fill(thus lowering the lifespan),and degrade the tire from overheating due to incorrect psi?i mean...this happens all the time.someone says 'you know.it'll corner better if ya lower that pressure by,say,7 lbs'.ya,okay...so they do and swear by it.but i'm referring to the top level of the tire's lifespan.if your gonna lower the pressure,why not just get a stickier compound,and fill to the mfg's specs.that's all i'm sayin.price does change with different compounds.probably lowering at recommended psi by a few pounds won't affect it much.hell,idk.some guys lower theirs to like 10 pounds below.when it heats up,then she's right around the 'cold' fill psi.which may not be beneficial for the tire.at 41 psi,it's gonna be up about 5-7 lbs at riding.that's why they say..'when cold'...so it reaches top performance out riding.i'm long winded.just talking,that's all.

* Last updated by: Grn14 on 3/15/2017 @ 1:47 PM *

Lets review what the specs say on the tires on my zx14

Metzeler Sportec M5 "E" - this is the stock OEM tire using
the "E" version of the tire for heavier zx14 loads.

Mine says.....

"Maximum load 805lbs at 42 psi cold"

Quiz.........

How do you read that statement? What exactly does that mean?

What happens if you put a 1,000lb load on the tire?

What happens if you put a 400lb load on the tire?

What is all this talk of taking it easy when you first take
off because your tires are cold and need to warm up?

How do tires warm up?

What happens if your tires are over inflated how fast do
they warm up and what will they warm up to?

What happens if your tires are under inflated how fast will they warm
up and how much will they warm up to?

How does driving pattern effect tire temps?

How does ambient temp effect tire temp?

and we haven't touched into reasons to use nitrogen gas to fill tires instead of pump air.

Yes, all the above can effect tire wear as well. Running to cold or to hot are
both concerns.

'How do you read that statement? What exactly does that mean?'...well,that means don't go over 805 lbs at 42 cold.rider weight,passenger,bike weight...right?Whatever the configuration.What do you see in that statement?

'What is all this talk of taking it easy when you first take
off because your tires are cold and need to warm up?'...idk...someone say to 'take it easy?I would imagine that's kinda just common sense...if it's 70 outside,i'd imagine the tire will be sitting safely around it's correct pressure,give or take.I sure sure wouldn't hammer my tires if the outside was 40 degrees.if it had been sitting at 40 degrees.but that's just me.

i mean,the cold psi is set to create maximum performance when it warms to it's operating temp.

* Last updated by: Grn14 on 3/15/2017 @ 3:06 PM *

Well I'll have to grade you a "F" on your quiz.

Not even extra credit for taking a guess at why one might use nitrogen to fill your tires.

Anyway, I give up, it seems you have a pretty good handle on this topic.

Probably best to just keep filling your tires to the max psi listed on the tires.

interesting...

Ok, let me try the quiz.
Say 42psi for 805lbs?
If the 14 weighs what 560lb and me being built like Barney Ruble at 220lb puts me at 780lb so I need less psi to achieve optimum pressure. I just shaved 30lbs with the new exhaust so now my combined weight is 750lbs requiring even less cold psi to support the total weight of the bike and me. But if I remove the cowl and take the woman for a ride I should increase the pressure to compensate.
Now lets complicate it with inert gasses. It is my understanding that nitrogen is thermally stable meaning it expands less as a result of temperature so I would run a little higher pressure to achieve my optimum riding pressure?
I run my Q3s just under 40 cold on the street and defer to the experts and run them at 30 on the track with pump air.
Would like to learn more about tires and traction because that's what keeps us on the road.

Dave

Yes, now we are getting somewhere.

(by the way I'm no tire expert or teacher)

Yes, loaded weight, style of riding and psi all work together. There is
no one setting.

On the tire it does not say "Recommended psi", "optimal psi", "For longest wear psi" it
states a "safety spec" for the tire.

Max load 805lbs at 42psi. - work it backwards, its saying you should not exceed 42psi maximum.
At 42psi the maximum load is 805lbs. If you start exceeding 805lbs the tire is going to
flex to much, overheat and you will crash and die. That is all that it is saying.

Motorcycle tires heat up by flexing the carcass. Unlike indy drivers that sway left to right
to warm their tires, motorcycle tires are different, you heat them up by accelerating and braking, not
left to right swaying.

Finding the optimal flex in the carcass to provide the proper tire temp is the goal.

Adding psi reduces flex, lowering psi increases flex.
Adding weight at same psi increases flex, decreasing weight and same psi decreases flex
Hard accelerating, braking and corning increase flex.

Tire temp will change things like longevity, stickyness, etc.

So how do you know what psi is best. you measure the difference between cold psi and hot psi.

For slabbing I shoot for a 3-4 psi increase in psi from cold.

For track I shoot for a 5-6 psi increase.

For track I'm really trying to get the tire as sticky as possible without
getting it greasy, or to much balling, or bluing.

A 3-4 psi increase from cold hot is a pretty good goal for most riding.

If you set your tires cold at 42psi and pull over and measure down the road and
you are at 43psi, your tires are to cold and not warming up. Over inflated.

If you start at 36psi and measure again and its at 40psi you are
on the money with a 4psi swing.

If you loose 100lbs the same measurement will not be the same. you will
not get the 4psi, may only get 2psi and you would need to drop pressure
to increase the flex like maybe 33psi, and you might get the 4psi again.

If you start out at 42psi and measure and you are at like 50psi your tires
are over heating. under inflated and you will crash and die. In this case exceeded
the max load capabilities of the tire because you can not safety exceed 42psi.

Just a few examples. Someone else can jump in anytime, I cant be the only
person that knows this stuff.

What's your preferred psi rise?

My 14 easy slabbing I run cold at 38-36 front and 34-36 rear.
Canyon action I start cold at 34-36 front and 32-34 rear
If I had a fat girl friend and a luggage rack I would probably
go right to max front and rear at 42psi and remeasure after riding a bit.

Track bike zx10 I start cold at 30psi front and 29psi rear.

This weekends trackday will be pretty hot at around 95 degrees, I'll need
to start a couple of psi higher to prevent over heating the tires, like
32 front and 31 rear. 1 psi can make a big difference.

Yes, fill with nitrogen which is more stable and produces less of a psi
variance in warming your tires. It's the unknown moisture content of the compress
air your putting in your tire that can change every time you refill the tires.
Compressed air compresses moisture along with the air, unless you have a inline
dryer or something.

That's my 2 cents and what works for me. I guess the best thing is
to experiment yourself keep notes and find what you like.

Personally I could care less how long a tire lasts, good grip is my only concern.

Id say street with the M5's I get around 2-2500 which I think is pretty good.

Track using street tires, Diablo's, Q3, Supersport, Power Ones, Powers, all get me about 300-400 miles a set.
Although I have mounted up some S21's for this weekend, hell I'll try them, I'm excited!

* Last updated by: piken on 3/16/2017 @ 4:26 PM *

"your tires are to cold and not warming up. Over inflated"...nah,i don't agree.they simply need to be ridden harder...but a 3 lb difference from say,42 to 47 is fine.42(cold) cannot be overinflated if that's what specs call for.if it's only increasing three or four lbs,that's fine.

Grn14 - Like I said earlier you have a pretty good handle this subject and
seem to be well-versed.

I posted more for the people that want to understand more on how motorcycle tires work.