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Discussion Starter #1
According to "Motorrad" the leading German Motorcycle Magazin, is the Dunlop D208 GP Racer M not suitable for high speed. They report that, the middle of the Tyre was gone after just a few kilometers max speed.
They drove all together not more than 155 km (90 mls), including warm up for the Engine and by far not all the time at max Speed. Which is even on German Soil not possible because of all the traffic. The asphalt Temperature was 15 degree celsius, the Tyre Temperature was at about 70 C after they drove about 80 km. At this Stage was the Tyre as new !
A certain Part of the 312R Production will be delivered with the Dunlop D208 GP Racer M.
"Motorrad" is investigating this Issue further and it expected to get a Feedback from Dunlop soon.
Until than You have to look at Your Tyre frequently if You are riding full speed, full throttle.
 

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Oppssss.... not good.

Thanks for the info. :friday:

Although it's not probable the 312R owners will be doing max speed for that many kms and although tha may have been a one tyre defect, it's always good to know that and be alert :f4:
 

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At high speeds the tire expands. They should check the clearance between the tire and the swingarm and make sure it meets Dunlop factory specs. In fact, if you look at the tire in question it appears to be destroyed more on the swingarm side then just in the center. I'm guessing, but could be the culprit as we've seen in the past racers even having this problem with tires exanding.
 

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Discussion Starter #5
You can find the Report at www.motorradonline.de. In German of Course. There was no comparison to a 1000R or S or what ever. They say this is not an Issue what is concerning for the Speed of the 312R only. Here they warn all high Speed Racers. By the Way they tested a Pirelli Dragon Supercorsa Pro in a second session and didn't had any problems.
 

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Gladio said:
At high speeds the tire expands. They should check the clearance between the tire and the swingarm and make sure it meets Dunlop factory specs. In fact, if you look at the tire in question it appears to be destroyed more on the swingarm side then just in the center. I'm guessing, but could be the culprit as we've seen in the past racers even having this problem with tires exanding.
That's a great point. But if it's an OEM fitment, that's not cool at all.

I'm pretty sure that tire can handle top speed of that bike. Those tires go around Daytona all the time on bikes probably going faster.

But then again, Dunlop does have race tire failures now and then. Not common, but I think it happens more with Dunlop race tires than others, based on limited personal observation.

Also note that street tires probably don't have anything to do with race tires in this case.
 

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Gladio said:
At high speeds the tire expands. They should check the clearance between the tire and the swingarm and make sure it meets Dunlop factory specs. In fact, if you look at the tire in question it appears to be destroyed more on the swingarm side then just in the center. I'm guessing, but could be the culprit as we've seen in the past racers even having this problem with tires exanding.
Yes, that's the most probable explanation.

I've also heard that the same thing happens with the 1098 and some racing tyres, but i don't know which ones.
 

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Just spotted a pic of Martin Finnegan in MCN this morning that shows him on MV with part of front guard eaten away . Dunlops on the bike.

Something to be aware of when changing rear sprockets and moving wheel forward.

Wonder if Martins bike shows any contact with Rad at the front ?
Juan ?
 

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Dunlops used to have very high pressure for there tires. 2.5bars front and 2.9bars rear, isn't it the same for the GP Racer? Maybe part of the explanation... plus, racing tires are not made for high speed highway use...
 

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Hey Ian.

Mine does :)

My Dunlop front rubs the fairing when I turn the wheel, and it rubbed the seperator between the radiators. Didn't hit the radiators that I could see though.

I raised my fender so that's not an issue either.
 

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Discussion Starter #12
Boys the Bike and the Tyre are with the Dunlop Tech's they will for sure offer an explanation. Until than keep an eyeball on it if You have those Dunlops. Other than that was it the original Tyre, and I guess most of You Guys will not watch Your Tyre after 40 miles high Speed. The Guys from Motorrad promissed to dig into it until they find the Reason and Dunlop will make a Statement for sure. I will inform You asap.
 

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macmivvi said:
Yeah Andy, but is that due to tyre growth or collapsed suspension?
Not sure. I know for sure the fender will hit no matter what unless I lift it, which I've done.

The rubbing on the radiator happened before I went to Road America, so I never really had the bike up to high speed while it was rubbing. So it must be a suspension thing.

After I removed that piece of plastic between the radiators, it never rubbed again, even at Road America. I was watching it. It will rub the fairing in tight corners if I'm on the brakes even a little bit. But the suspension does have to be collapsed to a certian point for that to happen.

On the rear, I have one of those honkin huge 190/60 D209GP tires, and it is really close to the fairing lower. The D208GP in the same size was too. And I'm pretty sure the side it was nearest was the same side as that photo suggests... If my chain was just a little shorter, I couldn't use the 190/60.
 

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probably the tire run without the correct pressure (low pressure) dunlop knows thise problem, and in a sort time we have good news to resolve this problem! very good news for all custumers of F4 1000 RR (R312)
 

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My Dunlop front rubs the fairing when I turn the wheel, and it rubbed the seperator between the radiators.
Mine too. My dealer recommended and fitted a 120/70 2CT and now it's eaten through the sides of my bellypan right back to the plastic. I'm not very happy about it, but we've not got a lot of choice in 120/65 anymore...

(I think this clearance issue is more of a problem on 750s than 1000s, possible due to longer suspension on the bigger bikes?)

Si
 

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TheCatWhisperer said:
(I think this clearance issue is more of a problem on 750s than 1000s, possible due to longer suspension on the bigger bikes?)
Si
The change in steering head angle from the 750 to the 1000 gives a little more clearance.
 

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I've got a 208 GP on the rear of my F4, it hasn't caused any problems to date but I've got a pair of Power Race Michelins on my spare wheels so I think I'll bung them on sharpish :wtf:
 

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Discussion Starter #20
A promise is a promise! Here is a concentrate of the Motorrad Article and the MV Agusta / Dunlop Report. I hope neither Motorrad, MV Agusta nor Dunlop feels offended by my translation. But I believe that this issue is concerning many 312 owners, not only in this forum.

Motorrad No. 15 07/06/07:
And high speed tests performed on May 6th with the F4 312R lost the Tyre, Dunlop GP Racer M D208, the running surface after not even 155 km (mearly 100 mls) by far not all distance with full speed. M is standing for Medium and means the medium soft compound.
The Tyre went first to MV Agusta SpA and than from there with the test Bike to Dunlop.
Dunlop responded, after several tests, on June 20th. In this statement declares Dunlop that there are problems at very high speeds. And is offering MV Agusta F4 312R owners to exchange this Tyres for free against other Tyres. MV Agusta is changing this Tyres already against Pirelli's if there are complains. The GP Racer D208 is, by the Way not mounted on any other factory equipped Motorcycle.
Well this leaves room to think about all the black magic. On the flanks of each tyre is the speed rating marked. In the case of the D208 a W for over 270 kph. But this isn't telling for how long this tyre can coop with which speed - 275 or 312 ? This has to evaluated by the Motorcycle Manufacturer, since the load capacity of Tyre is sinking with increasing speed. So carries a 170/60 ZR17 355 kg at 240kph, at 280 kpg only 231kg.
May it would would be a good idea if MV Agusta would participate at the annular Tyre Release Tests performed in Idiada (Spain). There are testing Tyre and Motorcycle Manufacturers together Handling, Grip and Shimmy. And ride intensively on a 7 km high speed oval. MV Agusta is performing their own Tests instead. Where they accelerate on a stretch of 2 km from 50kph to Vmax and hold this speed for 1000 to 1500 meters. Thereafter they drive for about 3 to 4 km with 250 kph. This procedure will be repeated for several times.

Statement from Goodyear Dunlop Europe:
As you know was the GP Racer D208 initially design for Track use only, in contrast to the Tyres from Pirelli, which You used to continue your tests. MV Agusta decided to use this Tyre because of the excelent handling caracteristics of the D208 after excessive tests, to equip the 312 with just this tyre.
The foreseen Tasks for the 312 aren't eternal high speed rides on an Autobahn, instead joy oriented rides with racing scenario. Rides where Acceleration and Movebility are stand in the centre of interest.
we are convinced that this tests aren't representing normal driving conditions. We repeated Your tests and detected - although we didn't came to exactly same results - noticable wear. Important is to mention that this is not leading to Air Pressure loss, flying off of the tyre surface or chun-king. We like to underline that there is no safety risk for that particular Tyre - as You have stated in Your magazin - but we are commited to ensure that every motorcyclist feels hundret percent safe in every possible situation. That's why we decided to exchange this tyres free of charge. The test procedures for a replacement tyre is shortly before completed, so that we can offer in shortest time a new product. MV Owners will be informed in written form by MV Agusta SpA how to exchange this tyres.

The statement was given by Alessia Riboni, MV Agusta SpA and Chris Aked, Goodyear Dunlop BV Europe.
 
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