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A friend has Dunflop D250 tires on his bike, running at 41 psi on the rear. He just replaced the rear about 4000 KM ago (about 2500 mi) and he has noticed cupping.

I've heard of a lot of issues with cupping on the front, especially if the tires are under inflated, but is it common on the rear with 41 psi? Any suggestions on what might be causing the problem and what a solution might be?

Like so many of us, he is riding heavy most of the time as he and his wife are both generously proportioned. I'm running E3s on mine and my wife and I probably run heavier than them. I'm running 41 psi on my rear and 38 in the front. After 8,000 mi. I have no cupping front or rear.
 

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JMHO! A cupped tire is due to a unbalance tire, the same happens to an automobile! I'm not trying to coerce, but I've been using dyna-beads since mounting a new tire. I have for the first time, rode a Bridgestone to past the wear bars and have no (zero) (nada) cupping! Keep your tires balanced, on the cage or motorcyle and you should'nt experience cupping or singing, plus air pressure is a must.......
 

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D250

I have the D250's on the 06. They were cupping at 6000 on the front. :wrong:Unless they start giving the D250's away I will be going with a different tire in the near future. Most of my riding has been one up and really not all that aggressive of riding.
 

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JMHO! A cupped tire is due to a unbalance tire, the same happens to an automobile! I'm not trying to coerce, but I've been using dyna-beads since mounting a new tire. I have for the first time, rode a Bridgestone to past the wear bars and have no (zero) (nada) cupping! Keep your tires balanced, on the cage or motorcyle and you should'nt experience cupping or singing, plus air pressure is a must.......

That would be true in one spot, the heavy spot. which would then appear as a cup. Cupping all the way around doesn't sound like an out of balance condition to me on a car thats usually shocks or alignment issues. I've got cupping at 6500 miles on my 250's and I have been running 41 front and rear. No out of balance shaking that I've noticed they are now very slightly vibrating and making the 'noise' when I lean into the cups. When I ride level no noise and no vibs.
 

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The POS D250 on my bike was removed after 6K miles. At around 2500 - 3K miles the bike had a wobble upon acceleration from a stop till around 35 MPH. It was bad enough to shake the bike to the point it felt like it was coming from the front.

I replaced the rear tire and the problem went away. The tire had severe cupping and feathering of the tread. The local dealership gave me a replacement tire / wheel combo off of a trike conversion.

The front D250 has 7K miles and looks like crap. I will run it till summer and replace them both, with either Bridgestones or E3s.

No out of balance shaking that I've noticed they are now very slightly vibrating and making the 'noise' when I lean into the cups. When I ride level no noise and no vibs.
Mine also made growling noises when just off center.
 

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A friend has Dunflop D250 tires on his bike, running at 41 psi on the rear. He just replaced the rear about 4000 KM ago (about 2500 mi) and he has noticed cupping.

I've heard of a lot of issues with cupping on the front, especially if the tires are under inflated, but is it common on the rear with 41 psi? Any suggestions on what might be causing the problem and what a solution might be?

Like so many of us, he is riding heavy most of the time as he and his wife are both generously proportioned.
I'm running E3s on mine and my wife and I probably run heavier than them. I'm running 41 psi on my rear and 38 in the front. After 8,000 mi. I have no cupping front or rear.
Been there....done that..... etc etc etc....
Two D250s went that route when we were on a long trip two wheeling.
Loaded up for the trips.
Definite cupping and wah-wah feel/sound by the time we hit 5-6000 mile range. Found the best tactic was to run the rear at 44psi and that helped a bunch.
First one was feeling like it was coming apart by 8-9000 and would not have put another D250 on but that was all the dealer had when we picked up roofing nail and had to replace while in Colorado.
My experience with 44 in the second one helped stop the deterioration but it was already cupping when I noticed it and went to 44psi from the common 41.
The third D250 I ran had a few thousand miles on it when I bought it with a used rear wheel. I ran it with 44psi and it was pretty much gone at 10000 (almost all two up fully loaded) with a little cupping showing.
I ran a Avalon on the rear that also had problems at 41psi when the bike was heavily loaded for a two up trip. The Avalon survived much better at higher psi, for those I talked with who ran it at 43-44psi also.
I found that I got better result and felt more comfortable running the psi a little high and seeing more uniform wear indications.
 

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A friend has Dunflop D250 tires on his bike, running at 41 psi on the rear. He just replaced the rear about 4000 KM ago (about 2500 mi) and he has noticed cupping.

I've heard of a lot of issues with cupping on the front, especially if the tires are under inflated, but is it common on the rear with 41 psi? Any suggestions on what might be causing the problem and what a solution might be?

Like so many of us, he is riding heavy most of the time as he and his wife are both generously proportioned. I'm running E3s on mine and my wife and I probably run heavier than them. I'm running 41 psi on my rear and 38 in the front. After 8,000 mi. I have no cupping front or rear.
The factory flops are - shall we say - inadequate. My '02 came with 'stones on her from the factory and I've run them since. The new front 709 wears SLOOOWWWLLLLLYYY and I got 15K out of my last one with minimal cupping. Rear lasts about 9K with some cupping.

The heavier the load, the more that rubber squirms.

Balance has NOTHIN' to do with cupping. Click here to see why.
 

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Don Flop around on your wheels...it's a common advice around here!
 

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I've had three sets of D250's and a set of E3's. The E3's lasted for almost 9K mi. But rode much worse than the D250's. I even scheduled to get the All Balls installed and was planning on putting on a fork brace. I got the tires first, and was glad I did. I had a set of Bridgestones installed and found that my wing rode and handled better than the day I drove it home from the dealer new! I have about 3K on the Stones and have no noise, no cupping, no sloppy handling, and no shaking at slow speeds. I am convinced, it's all in the tires. And I will only use Bridgestones in the future. Just my two cents.:shrug:
 

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I get scalloping of the rear tread, no matter the brand, when I get really aggressive on the throttle or engine braking on straight roads. I just happened to notice the fresh rubber skuffs on the sipes one day after blasting up my private driveway. Later, I found the scuffed-off rubber, in a loooonnnnggg strip on the blacktop; and I was not aware that the rear tire was even losing traction to that degree. I started looking at places where I had either gunned it or severely engine braked and noted similar rubber deposits. Oddly, such aggressive action on the twisty roads tends to counter the damage. My Cobra tires came new with sort of a scalloped profile, yet they are quiet and very grippy. Go figure?!?!

prs
 

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I'm in the club that believes most cupping is caused by low pressure. 41psi today, but maybe not in the past. 1K miles on a low tire is more than enough to screw it up. I've started keeping a chart of tire pressures on bikes that come in for service, so far 75% have had low tire pressures. When the list gets big enough to show a trend I'll post it on here.
 

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There is a "for-sure" cure for rear-tire cupping and noise in the turns.;);)
 

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Dunlop 250's

Dunlop 250's are no good! I personally know of three instances where 7500 miles was the best we got. Of late my brother-in-law had 7200 miles on his rear tire and it developed a bulge. He had to "deadline" it and ordered up a tow truck to have it hauled a dealer. In all instances the tires were run at 42-44 in the rear and 40-42 in the front.

My last set of E-3's I got 13,200 miles and could have gone another 2 or 3K but I'm planning a trip and didn't want to take any chances being 2Up and pulling a trailer. I had another set of E3's put on three days ago.

For some reason, Mother Honda puts the 250's on their new Wings. Retail on these tires are $3 less than the E3's. Guess the extra $3 dollars adds up for the Honda CEO execs Christmas bonuses...
 
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There is a "for-sure" cure for rear-tire cupping and noise in the turns.;);)
Yep , Trike it ! ;)

Daddo your friend is fighting a loosing battle , there are many variables in the picture , some have already been mentioned . But out of them all , I would agree that low tire pressure is a major contributing factor .

Most Winger's will tell you they always check their tire pressures , but you will find most don't .

Carry around a tire gauge and do a few checks on random bikes , you will find well over 90% are down .
 

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Yep , Trike it ! ;)

Daddo your friend is fighting a loosing battle , there are many variables in the picture , some have already been mentioned . But out of them all , I would agree that low tire pressure is a major contributing factor .

Most Winger's will tell you they always check their tire pressures , but you will find most don't .

Carry around a tire gauge and do a few checks on random bikes , you will find well over 90% are down .
You're 100% correct. I have customers come in on a regular basis whinning about their tires cupping out and the outside tread is wore off. When I ask them how much air they have been running in the tires, the number one answer now and has always been "What ever the book says". Put the gauge on the screwed up tire and show them 18 psi and they claim it was ok a couple of days ago. Year after year, this never changes.
 
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