Another tire wear thread... D211GPA

[needknees]

Sorry to bug everyone again but after the med/soft D209 fiasco I decided it wasn't worth running in the hot temps of summer on the (apparently) abrasive tracks of MAM and MPH. I called the TrackdayStore up and spoke with someone (Brian? Can't remember for sure) and settled on a set of D211GPAs with a hard/med rear. Got them mounted up and ran one day at Motorsport Park Hastings last weekend.

Info:
Track - MPH: Hastings, NE
Bike - 08 CBR1000RR
Suspension - Stock, baseline settings done by ducati omaha
Tires - D211GPA
Pressures - hot on warmers 33F, 23R. Off the track I was seeing 36F 25-26R
Pace - low 1:40s give or take.

The rear doesn't look to bad to me. Hastings is supposedly more abrasive than MAM, which is already pretty hard on tires. The front is what worries me . I've never had wear like this before.

Rear left side looks pretty damn good:

rear right side looks similar to the 209 soft/med (albeit the 209 looked worse than this after one session and this was after one DAY.)

---ran out of room for pics, see more in next post

 

[needknees]

Front right side doesn't look so hot

Front left side looks ok.

What's up with the wear on the right side? This was at a very clockwise oriented track so more wear on the right is not surprising at all but the wear on the front *does* surprise me. I've not had that happen to a set of tires before. It looks like a rebound issue to me but I am not sure.

Any thoughts on the right side of the front or rear?

 

[ninjamansc]

I'm interested in this as well. Was going to post up. The exact same wear pattern appeared on my front. It had to happen last session of the day because i would've noticed it putting on the warmers. I was getting a bad push from the front, but thought it was just because I was tired and was too firm on the bars.

 

[needknees]

I did a little more research and someone PLEASE correct me if this is wrong... but it seems like this wear was caused by too little weight on the front of the bike? Seems very plausible. I had some serious straightline instability a few weeks ago at MAM. Interestingly enough this wear did not appear until last weekend at MPH. It makes sense though because there's a couple VERY high speed, sustained right handers at MPH. Too little weight on the front tire, tire's pushing across the track and can't generate enough heat... Crazy tears.

Should I bump my rear preload up a click or two?

 

[Thunderace]

I've had little to no success running Dunlops on the rear of my bike. I don't have any problems with the front. I am a dumbass when it comes to suspension setup, so it may be me. But my rear tire looked worse than that after two sessions at A pace. I've run Michelin and Pirelli on the bike without any setup changes and the tires wear perfectly. Albeit, faster than I would like. But, I guess that's the cost of going fast. I would love to support the club and run the Dunlops, but I just have no confidence in the rear tire. I guess it's not too bad, because I bought my Pirelli's from the TDS.

 

[HighWay]

Looks like a cold tear to me. 33 hot off the track is what I thought the 211's were suppose to be run just like the 209's. My experience is with the 209's FWIW

 

[sobottka]

drop your off the warmer pressure to 21/31. 23/33 is what you want hot off the track. i doubt the pressure you were running would cause the wear your getting because i ran that same pressure untill i figured out how the dunlops work and i didnt get any wear like that. its hard to say just from looking at a picture of the front but i would say too much compression or too much pre-load/over stiff spring ....rebound too, it really could be anything.
was this the first time you rode since having the suspension set-up?

 

[erick1670]

Thunderace;140768 wrote: I've had little to no success running Dunlops on the rear of my bike. I don't have any problems with the front. I am a dumbass when it comes to suspension setup, so it may be me. But my rear tire looked worse than that after two sessions at A pace. I've run Michelin and Pirelli on the bike without any setup changes and the tires wear perfectly. Albeit, faster than I would like. But, I guess that's the cost of going fast. I would love to support the club and run the Dunlops, but I just have no confidence in the rear tire. I guess it's not too bad, because I bought my Pirelli's from the TDS.

Mmmm....I agree with here that the Michelins are way easier to monitor than the Dunlops. I run Michelins on my 600 and the only thing I have to adjust is the starting cold temp, b/c if is cold or hot the day you are at track, but I have 209's in the RC and I am being having some eissues there with the rear but is maybe b/c I have a med/soft, so to give these tires one more shot I will go 211GP 6680 compound to see how it goes. These tires grip wise are GREAT but finding how to monitor them is a pain, but well worth trying at least ones.

Love the Michelins but just giving the Dunlops a go

 

[Macon663]

Last time I checked dunlop didn't make a medium+ in the gpa, only the 211 ntec gp.

 

[jtsgsxr6]

Have you made any geometry changes lately?

 

[needknees]

sobottka;140808 wrote:
was this the first time you rode since having the suspension set-up?
I actually had a baseline setup done in late april by the "other orgs" tuner at most of their events, Ken Hall at superbike italia. But between then and now I had a fork seal that went out and I highly doubt the shop put the settings back where they were, and I was dumb enough not to record how many turns out it was before taking it in.

This was the first time I'd done a full day after having things re-setup. I ran a few sessions with the new settings and didn't see any wear like this, but it was on a different day, at a different track, with different tires... so not much to compare.

jtsgsxr6 wrote:
Have you made any geometry changes lately?

None. This is why I'm confused, I've never seen any wear like that on the front before.

HighWay and sobottka -- I'll try dropping the pressures a little bit but honestly this looks more like a hot tear than a cold tear to me. I'm kind of a newb at reading tires but don't cold tears generally have bigger chunks ripped out? these little fingers of wear are pretty thin. IIRC Dunlop recommends 23R 33F on warmers, not off the track correct?

 

[tomseviltwin]

I get better wear out of my rear 209 when I drop it to 21 off the warmers. It tears if its above that, and the faster I go, the worse it gets. This is just from my personal experience, though. I've never seen that kind of pattern on any 209 front I have run, so I'd be interesting in hearing about how you end up resolving this if you get a chance to post up once you figure it out.

 

[sobottka]

needknees;141045 wrote:


HighWay and sobottka -- I'll try dropping the pressures a little bit but honestly this looks more like a hot tear than a cold tear to me. I'm kind of a newb at reading tires but don't cold tears generally have bigger chunks ripped out? these little fingers of wear are pretty thin. IIRC Dunlop recommends 23R 33F on warmers, not off the track correct?

i believe 23/33 is a hot pressure not an off the warmer pressure and your correct hot pressure is off the track. this is what is recomended by race tire service (at least to me).
reading tires is not that easy and i dont personally know of anyone who can correctly do it. its a little easyier see the tire, the set-up and be able to push on the bike then try to fix it. that being said i've seen wear similar to that on fronts that are getting overworked. most likely from too stiff compression or spring or pre load ......but could be geometry or rebound as well.

 

[HighWay]

needknees;141045 wrote:
HighWay and sobottka -- I'll try dropping the pressures a little bit but honestly this looks more like a hot tear than a cold tear to me. I'm kind of a newb at reading tires but don't cold tears generally have bigger chunks ripped out? these little fingers of wear are pretty thin. IIRC Dunlop recommends 23R 33F on warmers, not off the track correct?

I'm no expert and I didn't stay in a Holiday Inn Express last night FWIW.

It is hard to say without seeing the tire but it still looks to be a cold tear to me. When a tire gets to hot the rubber will look melted and it gets pushed to the center of the tire due to centrifugal force. It looks like someone pinched the tire and pulled off some rubber; my understanding is that is cold tear. My other clue is the thread sipes are pretty clean looking and there is no “on/off” wear pattern like the tire is skipping on the pavement due to a rebound or compression issue. That’s my .00000002 cents.

If it was my tire, I would run it at 33 hot off the track and go from there. One thing you don’t want to due is change a whole lot of stuff and it doesn’t fix it. Eliminate one thing at a time.

 

[sobottka]

needknees;141045 wrote: But between then and now I had a fork seal that went out and I highly doubt the shop put the settings back where they were, and I was dumb enough not to record how many turns out it was before taking it in.

check your fork setting to make sure that the fork that had the seal replaced has the same amount of clicks or turns (compression and rebound) as the other fork leg. if assembled incorrectly you can have 3 turns on one side and 1.5 on the other..this would be a problem.

 

[sobottka]

HighWay;141069 wrote: I'm no expert and I didn't stay in a Holiday Inn Express last night FWIW.

It is hard to say without seeing the tire but it still looks to be a cold tear to me. When a tire gets to hot the rubber will look melted and it gets pushed to the center of the tire due to centrifugal force. It looks like someone pinched the tire and pulled off some rubber; my understanding is that is cold tear. My other clue is the thread sipes are pretty clean looking and there is no “on/off” wear pattern like the tire is skipping on the pavement due to a rebound or compression issue. That’s my .00000002 cents.

If it was my tire, I would run it at 33 hot off the track and go from there. One thing you don’t want to due is change a whole lot of stuff and it doesn’t fix it. Eliminate one thing at a time.

your not gonna get cold tear from 2 lbs over on pressure

 

[sobottka]

needknees;141045 wrote: Dunlop recommends 23R 33F on warmers, not off the track correct?

you are correct
http://www.dunlopracing.com/DETAIL-D211GPA.html
but i have better luck with the 21/31 as recommended by race tire service, not sure why this says 23/33

 

[erick1670]

tomseviltwin;141053 wrote: I get better wear out of my rear 209 when I drop it to 21 off the warmers. It tears if its above that, and the faster I go, the worse it gets. This is just from my personal experience, though. I've never seen that kind of pattern on any 209 front I have run, so I'd be interesting in hearing about how you end up resolving this if you get a chance to post up once you figure it out.

hi, yesterday I almost highside it twice in my 6th session, I knew that my tire was going to get kill so I was baby then in my morning sessions just to try to get to the end of the day but they dint, I hade a med/soft on the rear of my RC, may I ask you are you runing med/hard Dunlops on your rear of your RC?...

 

[Meat]

I run 23/32 hot off track (after my second full speed session) and about 21/31 off the warmers.

 

[tomseviltwin]

erick1670;141220 wrote: hi, yesterday I almost highside it twice in my 6th session, I knew that my tire was going to get kill so I was baby then in my morning sessions just to try to get to the end of the day but they dint, I hade a med/soft on the rear of my RC, may I ask you are you runing med/hard Dunlops on your rear of your RC?...

Yes, sorry, I should have specified that earlier. I use the med/hard rear. It seems to work well.