SAUDI BIKER! lol
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Tire wear
- Thread starter padu
- Start date
SAUDI BIKER! lol
awyala
Guest
Based on your pic, I can say I have never personally experienced this level of shredding of my tires, and it isn't the cold tearing I thought might be a result of low temps.
When you refer to this as rebound tear, is this the result of the rear getting slightly "light" after the rear shock has rebound and the suspension has returned to a neutral balance at the final point of corner exit?
Just as an indication of the type of wear I usually experience on the rear, I have attached a pic of a a rear tire at the end of 1 track day at Shannonville. My times there ranged between 2:02 to 2:06.
The OP and I are more likely in the same boat in terms of skill level, and a set of PCRs (for example) can serve up some serious performance and life before needing to resort to DOT-track tires.
awyala
Guest
Excatly! A great and humble guy, who sucked it up, moved on from his intital diagnosis and improved by leaps and bounds. I saw that too!
didn't we establish that the tire pressure for this particular tire was completely wrong on page 1?
Your tire is showing some very light signs of tearing.
Rebound tear comes from the shock packing down under hard acceleration on corner exit. It bottoms out then overloads the tire because the rebound is too slow.
Dunlops are very sensitive to being off temp. If ambient temps are below 20C there are very few riders out there that could keep a tire at ideal opearting temp. When most tires start to cool the grip starts to fall off, the Dunlops don't lose grip but that overloads the surface of the tire (causing cold tear) at a higher temp than you'll run into those problems with other tire brands. You can run a Medium+ compound rear, that nearly eliminates this problem.
Rebound tear comes from the shock packing down under hard acceleration on corner exit. It bottoms out then overloads the tire because the rebound is too slow.
Dunlops are very sensitive to being off temp. If ambient temps are below 20C there are very few riders out there that could keep a tire at ideal opearting temp. When most tires start to cool the grip starts to fall off, the Dunlops don't lose grip but that overloads the surface of the tire (causing cold tear) at a higher temp than you'll run into those problems with other tire brands. You can run a Medium+ compound rear, that nearly eliminates this problem.
awyala
Guest
Well to go back to what the OP stated:
It doesn't appear to be a heat cycle issue (given 2 track days with tire warmers....MP1 B compounds or not). It doesn't appear to be pressures either. He is on 28psi front and still experiencing "washing". Maybe dropping to 23psi at the rear may help with some hooking up, but judging by 1:26 to 1:28 laps on a 600, it doesn't seem that a slightly higher pressure rear is that much of a problem.
Could it just be getting on the power a little early?
I prefer to think riding style is a likely culprit before any technical / equipment issue, especially for riders with our level of experience.
A more consistent and harder track rider is in a better position to truly know how incorrect pressure or off tires feel.
The OP says John set it up for TMP (if I recall correctly), and with worn but not "killed" tires as the OP suggests....I would likely believe it was a riding style issue, or greasy tires (due to heat).
OP, by the way what was the air or surface temp when you felt the tires going off?
My money is on rider fatigue and style, IMHO.
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awyala
Guest
Generally speaking I am not hard enough on acceleration. I tend to be too smooth / timid on accelerating until I stand it up. At TMP I usually get smoked out of the final turn onto the straight by every 600 with gearing. I could probably pick up a second or two if I was muscling down that rear tire and shredding it like yours.
the same wear can be a result of compression damping issues as well.
photos of tire wear are really appropriate for diagnosis, unless there is a MASSIVE issue.
the more likely cause of that tire wear(Awyala's photo) is the rider whacking the throttle open after starting to stand the bike up on corner exit.
the same wear can be seen on novice, expert and pro level rear tires, it's just a matter of where it occurs.
you're a novice, so the wear is farther up into the sipes of the tire, closer to the center line,
This is the result of the beginning of wheelspin(you've got a 1000cc bike, it's easily done, even with the TC system enabled)
I'd consider myself an average, expert level rider, the wear on the same tire ridden by me would probably start just below the end of the sipes on that tire and extend to a few mm before the edge of the tire, the wear would probably be a bit more pronounced as I'd have more comfort spinning the tire at lean angle than a novice would.
The wear from a pro level rider would start below the sipes and be evident all the way off the edge of the tire, but it would fade from the edge, inward as the rider would be continuing to spin the tire as the stood the bike up and gained forward speed, where the tire stopped spinning and continued to drive the bike forward.
I've seen similar wear from the same bike, ridden by 3 different riders, same day, same conditions, one was a novice, customer purchasing the bike, I was one(the average expert) the fast guy was some Italian fellow that says DUDE a lot.
the who/where/why of the wear was explained by someone who knows a lot more about this stuff that I do, but theory made a lot of sense as the next time I was on the bike, I could base my throttle input on corner exit vs the lean angle and get a feeling for where the contact was at the time I started to open the throttle.
photos of tire wear are really appropriate for diagnosis, unless there is a MASSIVE issue.
the more likely cause of that tire wear(Awyala's photo) is the rider whacking the throttle open after starting to stand the bike up on corner exit.
the same wear can be seen on novice, expert and pro level rear tires, it's just a matter of where it occurs.
you're a novice, so the wear is farther up into the sipes of the tire, closer to the center line,
This is the result of the beginning of wheelspin(you've got a 1000cc bike, it's easily done, even with the TC system enabled)
I'd consider myself an average, expert level rider, the wear on the same tire ridden by me would probably start just below the end of the sipes on that tire and extend to a few mm before the edge of the tire, the wear would probably be a bit more pronounced as I'd have more comfort spinning the tire at lean angle than a novice would.
The wear from a pro level rider would start below the sipes and be evident all the way off the edge of the tire, but it would fade from the edge, inward as the rider would be continuing to spin the tire as the stood the bike up and gained forward speed, where the tire stopped spinning and continued to drive the bike forward.
I've seen similar wear from the same bike, ridden by 3 different riders, same day, same conditions, one was a novice, customer purchasing the bike, I was one(the average expert) the fast guy was some Italian fellow that says DUDE a lot.
the who/where/why of the wear was explained by someone who knows a lot more about this stuff that I do, but theory made a lot of sense as the next time I was on the bike, I could base my throttle input on corner exit vs the lean angle and get a feeling for where the contact was at the time I started to open the throttle.
awyala
Guest
Can't argue with that. Absorbing.
padu
Well-known member
Yuppers and I also said I dont think the tires are done, I just wanted to know when you know your tires are done,
But I'm learning on this thread so what the hell keep it coming
padu
Well-known member
If its my riding style i would figure it happens more then once but what do I know, I think it was due to heat, It was easy 32 that day and it happened on my last outting
Im going to set my front to 30 and rear to 23 and see what happens, Maybe the front wash was the tire flexing due to low psi
awyala
Guest
PM me with your email if you want a copy of a great tire wear article....if the link doesn't work:
https://www.dropbox.com/sh/hd3rewf9cxtqfli/hDk3ui142L
https://www.dropbox.com/sh/hd3rewf9cxtqfli/hDk3ui142L
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padu
Well-known member
I ran 26 hot in the rear and 33 in the front I allowed for 3psi increase so 23 cold turns into 26 hot. Etc etc bike seemed good but tire did sleep twice in the rebrand once in the front. I also changed gearing _ 1 and + 2 also tried running 90 percent of the infield in 2 gear lap timescale down a full second and a bit. What you guys think
you are making too many changes at once to figure this out,
make one change at a time.
The gear change will have a tire wear affect as you'll have more mechanical acceleration in the same gear at the same speed than you did with the previous gearing.
make one change at a time.
The gear change will have a tire wear affect as you'll have more mechanical acceleration in the same gear at the same speed than you did with the previous gearing.
jhgjhtyhj
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ROFL
Because we're talkin bout tires, how about:
*125/80R-17* KR448 Compound 32M3 (soft) @ 31psi cold (no warmers)
*200/55R-17* KR449 N-TEC Compound 7455 (med +) @ 21psi cold (no warmers)
Going on my 07 R1 at TMP Sept 2nd (will be a little chilly I'll assume, hopefully no rain! lol).
-Jamie M.
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