Tearing Tyres?

[Kat00]

This might help.
I finally found the answer to my problem.
Fucking rear spring.

http://img152.imageshack.us/img152/505/tiresreadingqb2.jpg

[GRL13]

well according tho them there pics, the rear on the yammy is perfect. :ayyy:
no need to do anything there, the front tyre has all over balling, not sure what that means but hey, it don't slip or run wide. what a lil ripper of a bike. fuck i love that thing.

[Poyda]

Good find Mick

Well The barge was set up right, and to think he set the rear spring by eye, that Terry Hays is a clever duck

We'll see how the intermediate barge goes soon enough

[Kat00]

Terry Hays is a clever duck



Wish he was as clever with mine.
I have got 10mm of staticg sag on the rear of mine.
Best rider sag I can get is 30mm and that is with the preload lock nut wound all the way down.
My tyre looks EXACTLY the same as the one in the second pic after 2 sessons. Last trackday it was destroyed after 4 sessions.
Clearly I need a different spring!

[MadHatter]

Good find.
Doesn't have a picture of the way my tyre shreds, which is front to back instead of left to right. I think that wear pattern is perhaps just a result of soft tyres on a hot track +zx10 powa. I get good mileage from my slicks in any case.
It looks like they have taken a photo of your tyre for the second pic.

[jasonbw]

reviving an old thread, but sure you wont mind.

Kat00 that website you found "Catalyst Reaction" (the site mentioned above) is run by one of the finest suspension tuners in the world... a well known bloke called Dave Moss...tuner to AMA top teams. He's now selling a DVD on suspension setup.. its basically a suspension setup night that was videoed, with cut in bits that are relevant.

So... I'm ordering a DVD (once their bloody site will take my CC details properly) and will be happy to share... but in the meantime, heres a few GREAT links to some video files that are part of this DVD. Thanks go to a member of the 1000rr.net forum for finding these.

I suggest right clicking as saving... to play, open the player file then drag the video file into it (after unzipping them all of course)

Player
Player (http://www.engtechs.com/temp/moss/player.zip)
Player alternate download (ftp://69.34.16.63/player.exe)

Suspenion setup 101.1
Class 1 (http://www.engtechs.com/temp/moss/MOSSclass1.zip)
Class 1 alternate download (ftp://69.34.16.63/MOSSclass1.flv)

Suspenion setup 101.2
Class 2 (http://www.engtechs.com/temp/moss/MOSSclass2.zip)
Class 2 alternate download (ftp://69.34.16.63/MOSSclass2.flv)

Suspenion setup 101.3
Class 3 (http://www.engtechs.com/temp/moss/MOSSclass3.zip)
Class 3 alternate download (ftp://69.34.16.63/MOSSclass3.flv)

The affects of rebound and compression
Rebound and Compression (http://www.engtechs.com/temp/moss/rebound_compression.zip)
Rebound and Compression alternate download (ftp://69.34.16.63/Rebound_compression.flv)

Types of tire wear due to incorrect rebound, compression, spring and/or other things
Tire Wear (http://www.engtechs.com/temp/moss/type_of_tears.zip)
Tire wear alternate download (ftp://69.34.16.63/type_of_tears.flv)

JasonBW

[dungbeetle]

hey bigdog..looks like our tyres were cold tearing i reckon.

[Bigdog]

Hmmm, or maybe hot tear?? I'm going to have to check my tyre pressures next time I come in from a session at EC.

[Bigdog]

On second thought I think you are right, cold tearing might have been the culprit. It was fairly cool today.

[dungbeetle]

yeh thats what im puting it down to,....the cold weather....seeing it didnt do it at pi..and the pressure was the same...but the temp was heaps lower...

[Zippa]

Bit worried about the wear pattern on the slicks after Eastern Creek. I have no idea about suspension, wear etc. Might even get somebody to give me a hand to measure the static sag next track day, just out of curiosity.

Soo any guru's like to have a stab at the cause. Keep in mind they looked great after 3 sessions at Oran Park on a nice sunny day, where as the race school was overcast & a little cool.

http://i32.photobucket.com/albums/d15/zippa05/CBR400/400tyrewear010a.jpg

[Dunno]

Mate im probably not much help in saying it may be the beastly power of the 400. I had a tyre do exactly that a few track days ago at EC. I figured it was cos I dont have tyre warmers & went a bit hot from the start. But you have warmers dont you?

[Bigdog]

What slicks are you running Zippa?

[Zippa]

What slicks are you running Zippa?

Yeah I run warmers, on Bridgestone slicks. Was running 28psi front & rear on the day.

Might go for a trundle over to the tyre technician at Eastern Creek (won't be Craig though I believe & see what he thinks)

[Bigdog]

Craig recommends 31 front and 29 rear psi on the Bridgestones, this might help a little but it does look as though you have some suspension issues too. I wouldn't waste my time asking the guys at EC, they don't have a clue.

[Zippa]

Yeah suspension could be a problem as all I have done is jumped on & ridden it, same as I normally do. I'll see if I can con somebody into helping mr measure sag etc before then also & check presures straight after the first session, anything to gain another second or 2 to keep ahead of the chasing pack from down this way :mod_smilie_rockwoot :mod_smilie_rockwoot

Thanks for the advice about the EC dudes, might go & have a chat to Steve at Maxpower before the day then. :confused1: :confused1:

[Bigdog]

I'm sure we can sort out the riders sag on the day mate, bring your measuring tape.

[striker]

What's the story with your rear shock? Is it standard? I was doing the same thing to my tyres. I took the bike to James down at SPM (see the "suspension guru" thread in the "ask a question" section). Problem solved. And it rode better afterwards.

[jasonbw]

I'm not guru BUT AT LEAST I WATCH THOSE DVDS I GAVE YOU!!! :)

Zippa fire up your DVD player and watch it.. it'll give you your answer.

Two problems this could be.. one is spring to hard or stiff, measure the sag and you'll know if thats the case because from that pattern it is either way out or its...
Hot tearing BIG time...

You have the DVD's, watch em... seriously it will tell you why and how and will show you an exact example of hot tearing that looks the spitting image of your tyre (very shiny band on the far edge, as you stand the bike upright and add power your getting those horrid lines of burning that radiate towards the centre of the tyre).

Hey guess what, I used my tyre changer today as a first practise... change the tyre on my spare rim... works well.. freaking hard to do it though but thats only because I'm not used to it... no doubt will become far easier as I practise.

[Zee]

Interesting.....
My tyres where hot tearing that day too.
You may have noticed me laying on the ground stiffening up my rebound Zippa, I also took 2psi out of the tyres.
It got rid of the hot tear but now I have a lot of debris all over the face of the tyre. :confused:
Now I don't know what to do next (how to fix the debris) back to that DVD. :confused1:
Thanks Jason :ayyy:

[jasonbw]

:) so welcome, just keep in mind I'm only reciting what the DVD said, I have very little intelligence of my own.

A debris field is fine, so long as it doesnt have a pattern... i.e. On a treaded tyre (not slick) if the debris field is all over bar a small unused like band forming behind the grooves then your tyre is bouncing due to a rebound problem (too stiff or too soft)... but even this one example has a caveat, if its in the portion of the roll on acceleration part of the tyre then its different to the hard acceleration part of the tyre... Those DVD's are great :)

If anyone can't (genuinly CAN'T - opposed to 'Can't be bothered') download from this site then PM me and I'll send you a copy of the two DVDs... so far I've sent about 10 copies out of the twin DVD set and havent asked for payment to cover postage, but I think since thats added up to $50 in postage alone I've got to start asking for $5 to cover the $5 prepaid postbag.

Actually I think its more, I've finished a 50 stack of DVD's, handed out a few but not so many... hmm.. yeah, I better ask for that $5.00

[Zee]

I actually have tried on several occasions to download them Jason but they never worked for me. I just put it down to a crappy Optus internet connection I've been having lately. Zippa burned me the first DVD but is having trouble copying the second. The information is excellent and am quite happy to buy originals. Only problem is, where do ya get them from so they work in Oz. :confused1:

[jasonbw]

me.. pm me your address and I'll send you the 2nd one... could you copy that for Zippa... actually scrap that last bit, I'll give him DVD #2 tomorrow at Oran.

[Zee]

Thanks mate :ayyy: and could you PM me your bank account details so I can fix you up for the 1st and now 2nd DVD.

[striker]

What are the DVD's and where do I get them. no doubt it's discussed in another thread but I can't be bothered searching for it.

[jasonbw]

1st sticky in the track days forum. click here (http://www.feelthetrack.com/) to find out what they are.
Or if you want to just see a low-res version to find out if you like it, click one Page 1 of THIS thread and scroll down to my post.

[Marcus]

I have very little intelligence of my own.



Same! lol




If anyone can't (genuinly CAN'T - opposed to 'Can't be bothered') download from this site then PM me and I'll send you a copy of the two DVDs... so far I've sent about 10 copies out of the twin DVD set and havent asked for payment to cover postage, but I think since thats added up to $50 in postage alone I've got to start asking for $5 to cover the $5 prepaid postbag.

Actually I think its more, I've finished a 50 stack of DVD's, handed out a few but not so many... hmm.. yeah, I better ask for that $5.00

Told ya.. Hit me up with some bank details please! Wouldnt mind the twist of the wrist DVD (not the credits one ;-))

p.s I second that its a hot tear but looks like another issue too! Maybe slightly too soft on the spring and slow rebound.

I reckon I have spring tear, its fine while cranked over and is mainly on the part where im gassing it out of corners. If I keep it as it is, I will need a new rear in a month!

[jasonbw]

show me more... need to see the leading and trailing edge of the tread, one that more horizontal than vertical... that a PP, just photograph slightly higher where the line goes to the edge...

The DVD focuses on exactly this stuff, rebound wear is indicated by a chamfering on the leading with a lip forming on the trailing... and the reverse too. The only rear way to tell whether its too hard or too soft rebound is by a knowledgable person pushing down on the bike (or watch carefully for how it should rise in the DVD).

Bank details NO... I told you - NO :) p.s. I gave it to reception here at work to post (yes, I paid her back) but it only cost her $3.70 to send... maybe I'm just ugly and they charge me full $5 rate normally... hmm or maybe I'm good looking and thats why they're screwing me.

P.s. Sorry - you might have already told me... whats wrong with the Twist DVD (bar the fact it stops after steering)... I dont understand the 'credits' bit ?

P.p.s. Ignore any advice I'm giving about tyres... my PP rear has only lasted 2000ks.. one gental CSS school and it was useless.. its now past wear bars... gotta get another now Frank Pons has sorted the suspension.. will last the right amount, love the PP's

[Marcus]

You can see a bit of rebound tear at near full lean which I think is more from trail braking then suspension.

[Turtle]

If your powering out of corners how do you tell the difference with just normal tyre wear and tearing :confused1: ????

[Zee]

That's not hot tearing just yet but there are two definite distinguishable wear bands which look like they continue along the circumference of the tyre. The debris field is consistent in the band which means, (I think) the tyre is following the ground appropriately. I'm thinking the first issue is tyre pressure. I would first lower the pressure to get a larger contact patch on the ground, therefore spreading the load to more of the surface of the tyre and as a consequence cooling it a little and evening that debris field to a greater surface area giving you in-turn more grip. But also, when you lower tyre pressure you may need to correct rebound dampening to control the extra bounce from a slightly softer carcase. What do you reckon, Jason.
You also have a chamffered leading edge but I don't see a lip on the trailing. I don't know what this suggests. :confused:

[Zee]

If your powering out of corners how do you tell the difference with just normal tyre wear and tearing :confused1: ????

Hot tearing is when the debris field points towards the centre of the tyre.

[Turtle]

Hot tearing is when the debris field points towards the centre of the tyre.

Cool..Thanx for that ZEEman.......:ayyy:

[MATTK6]

Interesting.....
My tyres where hot tearing that day too.
You may have noticed me laying on the ground stiffening up my rebound Zippa, I also took 2psi out of the tyres.
It got rid of the hot tear but now I have a lot of debris all over the face of the tyre. :confused:
Now I don't know what to do next (how to fix the debris) back to that DVD. :confused1:
Thanks Jason :ayyy:

if your tyres were hot tearing due to the temp of the day, wouldnt it be more a case of adding pressure to the tyres to decrease the contact patch on the tar? that's just what i've been taught by different people who are in the know about tyres and racing:ayyy:

[Zee]

if your tyres were hot tearing due to the temp of the day, wouldn't it be more a case of adding pressure to the tyres to decrease the contact patch on the tar? that's just what I've been taught by different people who are in the know about tyres and racing:ayyy:

I'm of a different opinion than what is regularly spoken about. I've explained it before but the way it works for me is: the road is cooler than the tyre (do we agree on that point) so, if this is the case, wouldn't you put down more tyre to cool it??? It's something I've found out about at OP but at EC with the same setup and similar condition the tyres behaved totally opposite to each other which leads me to believe there maybe something to do with the surface.

Anyone come across with this situation.

[MATTK6]

in theory i can see your point there zee, but if we may look at it another way.
i do agree that the tar is cooler then the tyre, so yes i agree.
But, if you were to add more rubber to the ground to try and cool the tyre more, this is actually increasing the temp in the tyre, as more rubber is in contact with the surface, you are creating greater friction between the 2 and by adding friction is the same as adding heat.
would agree with that theory?

[Zee]

I dunno about there being friction as tyre rolls or follows the road's surface normally but if the tyre is constantly being spun up or slid than yeah, plenty of friction. I thought most of the heat build up came from a constant distorting side wall.

[MATTK6]

yeah, the tyre done roll and follow the road surface, but just for arguments sake, grab a pen and roll it quickly between your palms and tell me if it gets warm? and friction as i was taught it: is anytime an object is in contact with another and moving, so if there was no friction, then there would be nothing to slow down or stop anything.
so everytime a tyre is in contact with the road an moving, friction is created between the 2, so therefor, friction is what creates the heat, apart from tyre warmers ofcourse:lmao:

If i have gotten any of this information wrong, anyone and everyone is free to correct me:ayyy:

[Zee]

yeah, the tyre done roll and follow the road surface, but just for arguments sake, grab a pen and roll it quickly between your palms and tell me if it gets warm? and friction as i was taught it: is anytime an object is in contact with another and moving, so if there was no friction, then there would be nothing to slow down or stop anything.
so everytime a tyre is in contact with the road an moving, friction is created between the 2, so therefor, friction is what creates the heat, apart from tyre warmers ofcourse:lmao:

If i have gotten any of this information wrong, anyone and everyone is free to correct me:ayyy:

Just tried it and I reckon the pen gets warm as a consequence of the two palms rubbing together more so than the rolling friction you speak about.

Any more examples??

[MATTK6]

ok, well your not meant to be rubbing your hands together, youre meant to hold your fingures straight and each hand touching only the pen, not the other hand:lmao:

ok, another example, tommorow if you take your car for a drive without doing burnouts or anything, before you leave, feel the temp of one of the tyres, then when you reach your destination, feel the temp of the tyres again, and i think you will find that even just general driving will cause heat to build up in the tyres due to friction of movement.
and if i'm wrong, then please let me know and i'll try your theory the next time out at the track.
and i have just thought of another example.
The boiling temp of water is 100degrees celcius correct?

howerever, it is possible to boil water at a much lower temp by reducing the atmospheric pressure. (this was proven to me by a teacher at tafe during a refridgeration course)

so, to transfer that info into tyre talk.

for arguments sake, say the boiling temp of a tyre while it's fully inflated is say 200degrees celcius.
and saying that fully inflated being say 40 psi in the tyre (these are just ref's)

by reducing the pressure in the tyre is having the same effect as reducing the pressure from the water to make it boil.
so there for, it would take alot less heat for the tyre to reach boiling point with lower pressure in it then it would if it was fully inflated?

and once again if i am wrong, please tell me and i will try your theory at the track:ayyy:

[_chado77]

im going run that arguemant by my Physics degree boss when he gets back from south Oz on monday..

i think matts correct.. the bigger contact patch the more friction(which cannot be removed due to wheel constantly rotating) will cause more heat and cancel out any beneifit from the colder tarmac(who's cooling effect has only by estimation under 0.1sec depending on speed to cool the tyre)..

hope that makes sense.. dont feel like busting out the uni books:hatter:

now too think of an experiment:confused1:

[MATTK6]

come on chado77, bring out the uni books, i just had to remember all the way back to tafe days which were about 4years ago:lmao:

[kellz]

should we call in myth busters???

u know ud get a good laugh from them trying it lol

[MATTK6]

actually kellz, that aint a bad idea:lmao:

[kellz]

actually kellz, that aint a bad idea:lmao:
of course it is a good idea, it was mine lol :lmao:

[MATTK6]

shit hey, this is one of the rare occasions that you werent having a blonde moment:lmao:

[_chado77]

thats a NO to the text books..:headshake: :) :)

but how bout an off topic experiment if you can call it that(the variables would be unlimited in all seriousness:lmao: )..

just done a simple

hot(Tap water)Represents tyre vs cold(ice cube)represents road.. on me finger (to see if which accumulates first)

just done approx 1 sec dip in hot water(not boiling) then a 1 sec touch on ice..

the heat accumulated more then the cold could disperse it..

so wih that just being genral heat with no extra heat added(friction) im definitely sticking by the less contact less heat theory ..

ok so it didnt actually prove much but still interesting:lmao: :lmao: :lmao:


now to do some proper test during a quiete day at work with boss to sort out some variables..



probably agood 1 for Myth busters to solve

[MATTK6]

what do you do for work chado77?
sounds like an alright place if ya got time to do that:lmao:
and why a no on the books?, come on, ya kow ya wanna:lmao:

[Zee]

Fuk, this is starting to get deep.

I don't think your wrong Matt, I'm just not convinced that all of the heat is generated from the tyre following the road's surface.
Didn't we learn something in chemistry that said, when two molecules rub against each other, that creates heat. I'm not sure that a tyre is actually rubbing the road, more rolling on it. What I think is happening is because of tyre deflection (tyre molecules rubbing together) is what I think is creating the heat. I'm sure there must be a percentage of heat coming from the tyre road surface contact but I'm not convinced that it is as high as what you speak of. What do you reckon???

[MATTK6]

yeah, your right, 2 molecules rubbing against each other does create heat, so unless your running a ROCK hard tyre, the amount of movement in the tyre when in contact with the road would be a rather significant amount, therefor creating heat.
and in saying that we're back to
HOT day = rubber melting more = molcules rubbing together alot faster.
Cold day = rubber staying cooler = molucules moving slower.
so by reducing the amount of melting rubber coming into contact with the road on a hot day would reduce the amount of molecules rubbing together.

[_chado77]

what do you do for work chado77?
sounds like an alright place if ya got time to do that:lmao:
and why a no on the books?, come on, ya kow ya wanna:lmao:

technical officer for a lining company(industrial).. its really varied from blast furnaces to acid tanks/bunds, pipes, sewers etc.. we line these with things like fibreglass, carbon fibre, bricks, ceramics, epoxys, various plastics and so on..

my boss loves experimenting and im sure we could turn it to work related:)

[MATTK6]

sounds like a fun place to work actually
and i'd be interested to see what your boss says if he's a master at it:ayyy:

[jasonbw]

What do cold ice cubes do to nipples?

[MATTK6]

now that's a different situation all together jason:lmao:
and one that's better left for the bedroom:lmao:

[Zee]

Great! I got a spare rear we can melt.

[MATTK6]

i would donate a rear soft slick, but i'm gonna melt that myself at the drags:lmao:

[_chado77]

quick experiment to show how much heat friction creates..

need push bike.. lift rear wheel pedal it as fast as you can ..

now skim spinning tyre with ya hand for as long as you can stand.. bet that burns..and thats at minimal speed and friction


now touch garage floor for relief .. pretty sure you'll be looking for a tap to get some relief not the tarmac:lmao: :lmao:

[Zippa]

:confused1: :confused1: :confused1: :confused1: :confused1: :confused1:

Think I will just wait for a helping hand to measure sag etc on Saturday morning.

Will also take all the suspension settings back to stock (if they are not aready there).

The guy I brought the bike off should be back from the ASC round at Philip Island (2x 3rds & a 5th placing in the 125's :ayyy: ) so will shoot him an email to find out if he knows what weight springs etc are in the front. I'm pretty sure its a CBR600 rear shock so not standard.

As for tyre pressure, will run 29's on Saturda y& keep an eye on things. Will also watch the DVD's that Jason donated to the Illawarra Riders & see if I can actually understand what the hell suspension actually does.:hatter: