Tire cupping

[Black_peter]

I'm noticing that the front tire is cupping.
What causes this?
How bad can it get.
When do I need to change the tire out?

Enquiring minds want to know..

[md86]

What causes it is too low a pressure , getting it too hot (those kinda go hand in hand) , and sometimes just crappy old tires from what I gather . It can get bad enough to make your bike handle REALLY wierd . If you can afford to , I'D probably change it out as soon as was feasable .

[Black_peter]

Thanks MD..
I'll check tire pressures.
I want to get rid of that crap mcaddam death tire in the rear anyway..

[KatanaO215]

yeah you need to change them as soon as possible. Mine were cupped really bad last season on the Kat (just the front tire) and it definately adversely effects handling. You can feel it when you get on the front brakes too

[Black_peter]

KatanaO215
Now that you mention it, I chirpped the front tire under hard braking the other day.

What is the suggested tires?
I read Fulcrum menttion the Power Pilots.

[md86]

Tires made of rubber should work pretty well ....
Everyone has a different opinion about which tires are the best , which suck , and what size you should use . SO for all intents and purposes , I guess you're on your own to figure that one out !

[Batgirl]

my front tire is doing that too...time for a change. If I could only find someone to do it ..SAAAAMBUCA!!!!

[KatanaO215]

KatanaO215
Now that you mention it, I chirpped the front tire under hard braking the other day.

What is the suggested tires?
I read Fulcrum menttion the Power Pilots.

yeah that will happen, and you can also feel a vibration when stopping hard.

Tires are more of a personal preference. Alot of people want Pirelli Diablos or Metzelars. Some last longer than others. I had Dunlop D208's on mine

[The CyberPoet]

My experiences indicate that scalloping happens predominantly on Michelin and Dunlop tires in hotter climates and/or when run too low on pressure. Typical scenario is pressure is set to suzuki baseline (32/36 -- pretty spot on for 140 lb load) and doesn't reflect the change in the tire shape due to a heavier load... then off you go on a day trip or longer haul. At this point, between the added deformation and the constant adding of heat to the tire from travel, the rubber in the center, where it contacts the road most of the time, softens up more than manufacturer intended it to (localized heat build-up) and the trailing edge of a tread block protrudes further than the back edge of the next tread block as it comes around -- wearing the tread blocks unevenly front-to-back.

IMHO: Can't go wrong with the Metzeler Z6 or Pirelli Diablo's. The Z6's will last longer and deal with wet surfaces better, the Diablos grip a hair bit better if you rail on dry ground.

Cheers
=-= The CyberPoet

[Black_peter]

I ran Metzler ME99 and Lazers on the CB and l-o-v-e-d them.. Dry or wet (amazing in the wet IMO)

Thanks Cyber, I'll start pricing Metz's.
We have the sudden thunder shower here and
I'm not knee down yet..

[mystahagy]

I'm having a problem with cupping of my front and rear on my '95 with some Z6's. Both are almost identical. I was running 34/36. Went up to 36/38, I don't see how you could correct a cupping problem, but maybe it'll improve.

[The CyberPoet]

I'm having a problem with cupping of my front and rear on my '95 with some Z6's. Both are almost identical. I was running 34/36. Went up to 36/38, I don't see how you could correct a cupping problem, but maybe it'll improve.

If you are getting cupping on both ends with the Z6's, you are definitely running way too low on pressure for the actual load weight (bike, rider, gear, possibly passenger and cargo) -- and you may want to check your tire pressure gauge against a known good one. At 200lbs, I tend to run 35.5 - 36 psi front / 38 - 39 rear (R) or so, and up that more if I'm going to be hauling a passenger and/or additional load.

The other things that may be happening in your situation:
Not checking them frequently enough;
that you are checking them warm (such as at a gas station a half mile away -- they warm very quickly), OR
perhaps you are checking them in the evening for the morning's ride -- and the temp in the morning is substancially lower (which drops the pressure)

Rear tire cupping (scalloping) is extremely rare on any brand of tire, and is a sure indication that the tire is being used incorrectly (too low a pressure, or a rubbing rear brake caliper catching a specific point on the rotor).

Cheers
=-= The CyberPoet

PS - your tire gauge may be off...