tire cupping

[nimblekat]

What causes (mainly the front) tire to cup if you have adiquate air preasure. I thought tire cupping was do to under inflated tires.

[Nero]

I say it really has to be the tire pressure. The outer wall is holding the weight of the bike while the inside rides lightly on the road. I've never seen any other answer for it.

[Black_peter]

From a car site but still:
What's Happening
The tire is not tracking straight down the highway, but is bouncing sideways during parts of its rotation. It may be wobbling on the axle or rim. On trailers, the condition is aggravated by running empty. Because of the light load, the trailer begins to bounce, creating more irregular wear, which creates more bouncing, and so forth. The bouncing can create vehicle suspension component wear.

Probable Causes
- loose wheel bearings
- mismounted tire/ wheel assembly
- out of balance wheel assembly
- tread design/ tire design
- worn bearings, shocks, springs or other suspension compnents
- mismatched duals
- inconsistent dual inflation (10 PSI or greater)

[nimblekat]

When I bought my 2002 Katana the front tire was cupped bad but it had almost 9000 miles and 18 pounds of air in it. I have since replaced that tire with a new Bridgestone. Can I expect my front tire to cup even if I keep 36 pounds of air in it and do most Kat riders find that there front tires cup at some point in the tires life.


2002 Katana 600
1999 Caravelle 209
1990 Ford F150
2001 Mercury Sable LS (Wifes Ride)

[rwcreigh]

[quote="Black_peter"]From a car site but still:
What's Happening
The tire is not tracking straight down the highway, but is bouncing sideways during parts of its rotation. It may be wobbling on the axle or rim. On trailers, the condition is aggravated by running empty. Because of the light load, the trailer begins to bounce, creating more irregular wear, which creates more bouncing, and so forth. The bouncing can create vehicle suspension component wear.

Probable Causes
- loose wheel bearings
- mismounted tire/ wheel assembly
- out of balance wheel assembly
- tread design/ tire design
- worn bearings, shocks, springs or other suspension compnents
- mismatched duals
- inconsistent dual inflation (10 PSI or greater)[/quote
old tire

[jgalar]

http://www.rattlebars.com/valkfaq/tirewear/index.html#CUPPING

[The CyberPoet]

BP: I don't believe that MC tires tend to cup/scallop for the same general reasons as car tires. Swapping brands & pressures has alleviated the issue for me and others... implying there wasn't any bad bearings/bent axle/etc.

When I bought my 2002 Katana the front tire was cupped bad but it had almost 9000 miles and 18 pounds of air in it. I have since replaced that tire with a new Bridgestone. Can I expect my front tire to cup even if I keep 36 pounds of air in it and do most Kat riders find that there front tires cup at some point in the tires life.

Tire cupping/scalloping is (in my experiences) primarily from concentrated heat in specific sections of tire that get excessively disformed as the enter/leave the contact patch. Some brands & makes are more susceptible to it that others. Rider/load weight, tire pressure, tire composit, tread design, ambient and road-surface temps all play into it.
With the Kat being a particularly heavy bike, it tends to scallop or cup tires more readily than lighter bikes, and Dunlop 205's/207's & michelin Macadams (90X & 100X) tend to do it worse than many other tires (unfortunately, these were the OEM tires on the 98+ Kats in the North American market).
I'm a prime candidate: living in Florida (hot weather, hot road surfaces, long distances between places), being a bit portly, and having eaten a lot of highway miles on two different 98+ Kats (600 - 1000 mile days on the road)... Happened on the Macadams, happened on the Dunlops (both listed above), but it's never occurred for me on the Metzelers (in part because the manufacturer recommends higher baseline pressures). And I am religious about tire pressures. The only cupped Z6 I've ever seen was Malloc's, and he was at 26 psi when I checked his front tire (typical example of lack of pre-ride attention-to-detail and lack of general maintenance).

Cheers,
=-= The CyberPoet

[Nero]

You sure you didn't order the 'pre-cupped' version of the tires?

[Black_peter]

BP: I don't believe that MC tires tend to cup/scallop for the same general reasons as car tires.

Well no reason not to check...
Eliminate the possible causes and whatever remains, no matter how unlikely, must be true, to paraphrase Sir A.C. Doyle..

You sure you didn't order the 'pre-cupped' version of the tires?

I got those with my Katana!

[tnvatdreamland]

Re: tire cupping

What causes (mainly the front) tire to cup if you have adiquate air preasure.

Dunlop Sportmax tires.