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Have you had cupping?

  • On V-Rods

    Votes: 42 65.6%
  • On airheads and / or bigh heavy tourers / cruisers

    Votes: 6 9.4%
  • On sports bikes

    Votes: 8 12.5%
  • Never had any cupping on anything

    Votes: 15 23.4%
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Posting From The Pub
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Discussion Starter · #1 ·
I've never seen this supping thing on other bikes, and judging by another thread it could be that Harley's tyre pressures are a bit low.

Have you seen cupping?
 

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Part-time mod
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Had it on the front stock Dunlop, so I went to Metzlers. Problem solved, in my case.
 

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Color me Gone
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I think your missing tire options in your poll. My dunops cupped when I had them but the metz don't.
 

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Safe and sound
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Max said:
I think your missing tire options in your poll. My dunops cupped when I had them but the metz don't.
:them:
 

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Kiss the Ring
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Silly question but not beeing a native english speeker, I have no idea what "cupping" refers to exactly... Anybody could explain or post a picture so I can look for it?

Thanks!
 

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Les pneus prennent une forme concave sur un cote. On le voit surtout sur les pneus Dunlop en avant.



(Just translating for Irréductible)
 

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1130cc Ninja
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i have had cupping issues with every sportbike tire I have ever run

I typically run weird tire pressures in my tires and this leads to that. I run around 30-32 in my front tire and around 38 in the rear tire. I never have bad issues with the rear cupping but the front is always worn out on the sides well before the center. I prefer this combo of tire pressure due to my riding style. I tend to slide out the tail going into a turn hot then grab the gas and power through the turn. With the tire pressure closer to normal the rear can slip and grab just fine, with me keeping the tire pressure lower in the front it has a little better adhesion to the road so when the ass i sliding the front is still pointing the bike in the right direction.

so back on topic, cupping is mostly caused by low air pressure
 

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Speaking of...

I run my Metzler Marathon's at 36 psi in front and 38 psi in back.

What do you guys keep them at?
 

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’07 VRSCAW ... Dunlop Elite 3 … OEM tires

FWIW… Both Metz and Avon websites say they have no tires in their lines recommended for the VRSCAW. (Yet?)


At 4100 miles I took bike to dealership for diagnosis of minor but worsening front-end wobble at certain speeds. After checking and adjusting a lot of other things, they got around to checking the front tire. They reported cupping and the tire was replaced with a new one. The wobble is gone now.

I have the old tire and it indeed has noticeable cupping. Due to the alternating pattern of the tread resulting in an alternating pattern of the cupping, I am convinced that this was the cause of the wobble, despite a decent amount tread remaining. (Maybe alternating isn't such a great way to manufacture tread patterns?)

The dealership’s service desk rep said that the tire cupped due to “under-inflation” (it was kept at the HD spec pressure of 36f), and that "we" recommend tire pressures of 42f/44r on this bike.

I pointed out that both the owner’s manual and service manual state 36/38 and that the tires have been religiously kept at that HD recommended pressure for their entire brief lives. He stuck by the “under-inflated” position, and reiterated their 42/44 recommendation despite the official HD line.

I later talked directly to the Service Manager who staunchly recommended inflating the tires to the max cold pressure indicated on the tire - 42f and 44r.

I called Dunlop and got yet another answer. The Dunlop rep said they recommended 36f /42r, despite the fact that the Dunlop literature and warrantee info specifically states “Maintain tire inflation and load in accordance with motorcycle owner's manual, tire information placard and restrictions molded on tire sidewalls.”

Three answers so far for these "Dunlop Elite 3" tire pressures (f/r):

HD Manuals: 36/38
Dunlop rep: 36/42
Dealership: 42/44

Opinions?


P.S. .. good explanations of tire wear here:
http://www.rattlebars.com/valkfaq/tirewear/
 

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Kiss the Ring
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2,203 Posts
mikep said:
Les pneus prennent une forme concave sur un cote. On le voit surtout sur les pneus Dunlop en avant.



(Just translating for Irréductible)
Merci mikeP!! La c'est clair!!

So no, no cupping on my Dunlop's... Mike, did you find a good deal on the Metz in Montreal? If so where?
 

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Tired of the crap
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Got V said:
Opinions?
Overinflating (as recommended by the service manager) is probably as bad an idea as underinflating. You might possibly reduce "cupping" - but you will do so at the cost of seriously compromising the grip you have on your front tire.

It might be "nice" if motorcycle tires lasted for 40,000 miles - but they don't, and probably shouldn't. Motorcycles rely far more on their tires having good grip than do car tires, and as a result they are generally made of much softer compound than car tires. Also, since motorcycles lean to turn - again unlike cars - they need tread going up part of the sidewall. When this is worn, the tire is shot.

The reason that the Metzler tires cup less than the Dunlops is because they have a harder compound, and presumably less grip. Its probably difficult to notice this in most riding situations - but grip is pretty important when you need it most. Think about that before changing brands.

The max. tire pressure figures on the sidewall are just that - the maximum safe pressure that the tire has been tested at. It is pretty much irrelevant as a guide for how much air you should put in your bike tires. Follow what the manual says.
 

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The last 2 sets I bought were in the US. I keep my bike south of the border in the winter. She's spoiled that way! :)

An easy way to buy things in the US if you don't mind going to Lacolle to pick them up is just have them delivered to this place below. They charge $2 US per box they hold for you.

http://www.freeportforwarding.com/instructionsFrancais.htm

You still pay taxes, but that's generally it. And you would have to pay them anyways if you bought them here.

Otherwise, I just get my stuff at HD Montreal. But not the cheapest way to go.
 

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Kiss the Ring
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mikep said:
Otherwise, I just get my stuff at HD Montreal. But not the cheapest way to go.
I have unconditional Love for them... So this option will be last resort.

Do you actually have to cross the border for this service or is it on canadian side? Our southern neighboors wont let me in anymore :angeldev:

Thanks a bunch Mike!
 

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Kiss the Ring
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sorry mike should have cliked the link first.. all the info is there..

thanks again
 

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Blowin' Smoke
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I put 35K miles on the OEM Dunlops and every front tire cupped. I ended up changing both whenever I changed the rear because of it. I tried various air pressures and found that less than recommended in the manual exacerbated the cupping on the front.

I changed to Metzelers and haven't looked back. No cupping, even wear on both tires, and better stability in turns. I found that when the the front Dunlop was cupped out it felt jittery in turns. I haven't enough miles on Metzelers yet to discuss longevity, but I believe I'll get at least the same mileage per tire that the Dunlops provided. And I won't have to replace the front every time I go through a rear. :)
 

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Posting From The Pub
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Discussion Starter · #18 ·
Do Metzelers have a harder compound?

I don't agree that softer compounds will cup. I've been riding on soft compound Bridgestones on sports tourers forever, and until I joined this conf I'd never even heard the word "cupping", let alone suffered from it. My fronts wear as I would expect - they triangulate from cornering forces and still being on the brakes as I commence the turn-in. If the tyres are "cupping" something somewhere is not working as designed, or being used as intended.

Hence the thread - I'd like to know what.

[edit]

Oh yeah, I had some Michelins once, on a VFR, where the front blue-ed up and stopped gripping, and I had to replace it. Still no cupping though.
 

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Louis said:
If the tyres are "cupping" something somewhere is not working as designed, or being used as intended.
The various explanations I’ve read do not suggest that cupping is a result of anything wrong (except arguably tread design.) Instead it seems to be a normal wear pattern for motorcycle tires with some tread designs apparently being more conducive to it.

I’ve been told by the service manager mentioned in an earlier post that Metzelers are actually softer than the Dunlops on my bike (Elite 3). I’d suggest that it is the tread design of certain Dunlops - large simple wide alternating tread grooves - that is largely responsible for the larger more noticeable cupping. Is it possible that a more complex tread design on your sport tourer produced smaller insignificant cupping that wasn't noticeable?


The following excerpts from the site I linked in a previous post seem relevant.

Scalloping, often called cupping, “...is a natural wear pattern on motorcycle tires and it will always follow the tread pattern”… “It merely shows that your tire is indeed gripping the road when you make turns” … “This cupping develops within the side wear bands of a leaned motorcycle.” … “The leading edge of the tread does not flex much as it grips the road and the rubber is scuffed off the tire in that area causing a depression..."... “The more complex the tread pattern, the more complex the cupping pattern will be. The softer the compound of the tire, the sooner this cupping will develop. Radial tires are more prone to cupping than are bias ply because the compound of radials is softer.” … “Low tire pressure will exacerbate this wear pattern…”… “Improper balance has nothing to do with cupping on a motorcycle tire.”


I also found the following explanation to be interesting, received and posted by the same website:

“The following textual illustration comes from Martin who contributed to this article by E-mail on June 26, 2006: I was just reading your bit on "cupping" and thought I'd share with you how I describe what's going on. I usually tell people that what's happening is that the individual "blocks" or "islands" of tread are squirming and deforming due to the forces applied to them during cornering and braking. When this deforming takes place, the wear is naturally not evenly distributed across the surface of the tread. (I define a tread block as an area of the tire surface surrounded by a groove.) I next tell people they can demonstrate to themselves what's happening by taking a new pencil with an unused eraser on the end and while holding the pencil perfectly vertical, push down and drag the eraser on a rough surface in one direction. Then I tell them to look at the eraser and note that all the wear is on the leading edge and not evenly distributed across the end surface of the eraser. It seems to make the concept easier for many to understand. Cheers!”
 
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