Cupping

[slapnpop]

I don't know where the term cupping came from.

If you were to flatten the tire so it contacted the ground flat like a tank tread, cupping would refer to a wear patter than looks like a saw blade from the side. It's caused by the most extreme forces in a tire being generated in one direction only. Since the front tire doesn't drive the bike at all, the extreme forces on the tire occur in braking and when leaned over on it's side.

I'll use braking as the example because it's easier to describe.

Go back to the tank tread analogy for a minute. When you brake, the part in contact with the ground stays stationary, while the bike and the wheel, and the top part of the tire continue trying to go forward. All of the individual sections of the tire tread are going to lean forward slightly while the top is being pulled in one direction and bottom in another. Of course the leading edge os going to dig in more, and the trailing edge is going to lift up slightly as the block tilts, so the leading edge wears faster than the trailing edge. All of this is going on in each individual block of the tire tread. After a while, the leading edge will be shorter, and the trailing edge taller, and when you have two sections side by side, there will be a difference in height from one tread to the next. (look at the above posted pictures again and it's pretty easy to see) This is what causes the tire to "hum" or "rumble." Of course the back tire wears in just the opposite direction because the strongest forces are generated in acceleration. When the rear tire is used to brake, it will wear in the opposite direction of when acceleration, so the overall cupping factor is less on the rear tire.

All tires will cup to some degree. Sport type bikes put a lot of force on the front tire in braking quickly, and the FJR is very heavy which only makes it worse. The tire tread pattern also makes a big difference.

Most importantly however is your riding style. If you gun and brake and gun and brake, and lean all the way over on the tire braking heavily, you'll cup your tires much faster.

 

[Captain Obvious]

If it is such a standard accepted term, what does it mean? What does it refer to?

It means just that. The tread looks cupped.

How can I tell my tire is 'cupping' instead of just 'wearing irregularly'

It's the same thing. Cupping is the tire "wearing irregularly"

Huh?

Huh?

How can I prevent it?

You can't

Does it happen to all tires/motorcycles or is the FJR more prone to it?

No. No. Tire/Bike combinations, loads, surface condition and riding style all play a part.

How many miles should I expect out of my tires before it is inevitable?

It's not inevitable. So the answer is unknown mileage.

Tire pressure? Does that have an influence on this 'cupping'?

No.

Lemme know, since y'all are so fuckin smart and know all about these things and being an FNG, I don't....

Now you know.

 

[FJRSTAR]

Slapnpop,

Now that is an excellent reply and most likely the one that Scythian was looking for.

The other mean and uncalled for responses never should have occurred in the way that they did.

Newbies ask questions and they should not be considered dumb questions.

There are no dumb questions when asked by an FNG.

 

[FJRSTAR]

QUOTE  Tire pressure? Does that have an influence on this 'cupping'?

No.

Actually, from what I have read here and at the EZ board since its inception, many have posted that tire pressure can affect cupping.

On the factory Bridgestones, tire pressure on the front has been recommended to be at no less than 42 psi. By keeping that on mine, it has helped prevent premature cupping.

I have over 10,000 miles on the front and there is some cupping but not severe and there is alot of tread remaining as well. I have had to replace the rear already.

I tend to agree that tire pressure does make a difference. Low pressure is bad, 42 psi is best.

 

[benneyb]

I don't think they were breast fed when they were kiddies.

The first step to a life-long journey of deprivation and misery.

Most of the gang here are pretty good and have a great bank of knowledge as you have just found out,

That is for d*mn sure, and makes this board an invaluable resource!

 

[twowheelnut]

The other mean and uncalled for responses never should have occurred in the way that they did.

To which I would reply:

Then please, please, please, watch this PSA:

PSA

By the way, 'cupping' not only is a term used in the design of a ladies' bras, but this condition occurs in automobiles, as well.

 

[Warchild]

Lemme know, since y'all are so fuckin smart and know all about these things and being an FNG, I don't....

:lol:

Alright, I'll give your questions a shot.

If it is such a standard accepted term, what does it mean?  What does it refer to?

The tire cupping phenomenon is a common occurrence on big, heavy sport-touring rigs like the FJR (and most bikes for that matter). You should not be all that concerned when your front tire starts to display the "scalloping" or "cupping" tread wear pattern in the mid-to-latter lifespan of the tire, because it's more-or-less normal behavior. "Cupping" or "scalloping" in not atypical pattern wear; it actually indicates proper use of your front brake. In fact, it is the front brake action that causes the front tire to cup, and I'll discuss why that is in a moment.

Does it happen to all tires/motorcycles or is the FJR more prone to it?

Some tires are *more* prone to develop the scalloping than others; this is primarily due to their tread design. On the FJR, the Bridgestone BT-020 and Dunlop D220 are two of the worse offenders; the Avon Azaro ST-45 and Michelin Pilot Road are two examples that tend to resist scalloping until the latter third of their treadlife. Most all bikes generally present cupping to one degree or another; usually, the large, heavier ones display it sooner than the lighter, sportier ones.

How can I prevent it?

You can't. There are some things you can do to delay it, or minimize it, but you really can't prevent it. So don't agonize over it. Seriously. It's not *that* big a deal.

How many miles should I expect out of my tires before it is inevitable?

Entirely dependant on your tread pattern, your tire maintenance, your riding style, your roads conditions, etc, etc, etc. Lot's of variables come into play in this scalloping phenomenon. Keep your air pressures up on the higher side, and you generally can delay it to the latter half of the tire's normal treadlife, depending on your tread design and riding style. Again, tires like the BT-020 and D220, you'll see scalloping much sooner than other, "rounder" tread designs like the PR and Avon..

Tire pressure? Does that have an influence on this 'cupping'?

Absolutely, and it's one of the few variables you can make a positive impact with regard to delaying the inevitable. If you keep the tires aired up to it's maximum settings (generally, 42 psi), cupping will be reduced, and delayed. But not eliminated. Eventually, the tire will cup. It is a normal trait on the FJR.

And the Connie. And the ST1100. And the FJ1200. Gold Wings. BMWs. Most any of the larger bikes with modern steering geometries are going to display it. Completely normal. Like I say, some tires are more prone to it that others due to their tread design.

Now... as to the actual, *physical* reason why it happens: it is the front tire braking forces at work. Consider the following:

Imagine you are running alongside the left hand side of the bike at whatever speed. As you go down the road and look over toward the bike, the wheels are (obviously) turning in a counter-clockwise direction as you look at them. When the brakes are applied, the net braking "effect" is that where the tires want the "turn" in the opposite direction (clockwise) in order to slow down/stop. Now obviously, the tires aren't *actually* going to start turning clockwise; I am referring to the braking force's "net effect" acting upon them. Now look at an example of a "cupped" tire. See how the "trailing" edges of an individual tread lug are worn down, but the "leading" edge is not? That's because the braking forces are causing the trailing edges to bite into the asphalt (remember, they are trying to "spin" clockwise) and the result is that they wear faster than the leading edge. Ergo, the tire eventually cups.

Did that answer your question?

 

[FJRSTAR]

by Thug...You will notice the cockheads will feed off each other, you know, let's hang shit on someone and give em heaps for no other reason, the type that would never have the guts to say it to your face if they ever met you. But on the whole it's good place most of the time.

I wholeheartedly agree. Lots of the shit that is said here won't be said to your face.

Scythian,

There are many here that are willing to help a newbie or anyone else without the nonsense you have experienced so far in this thread.

 

[Bounce]

deleted - not worth the time it would take to add to the thread

 

[BrunDog]

In my opinion, any jacksqueeze that kicks the door in and fires away deserves to be called an asshat or whatever helps you make the point.

Before you get antagonistic and engage in heated discussions, you need to earn the respect of the forum. Like adding some assistance or solving a problem or creating a new or better farkle.

And how the **** dare you come in here and say that this forum is a waste of bandwith. If I were an admin I would gladly save you some.

-BD

 

[Scythian]

Actually, the terse responses didn't start until the reaction to the first (helpful) replies were met with a verbal slap in the face by the originator of the thread.

Did you actually read the thread?

It went off the rails when the links provided came with:

"That's what you get for Googling for 15 minutes, you should try it sometime."

I replied that if I can just google every tech question, why not get rid of this forum?

Then I got called 'asshat' for not liking the "heres a link, Google it yerself response"

You forgot about those parts....

 

[Bounce]

never mind

 

[Scythian]

And how the **** dare you come in here and say that this forum is a waste of bandwith. If I were an admin I would gladly save you some.

That was in response to the 'try googling it yourself' comment.

If I could find every tech answer on google, and the response to every question is 'google it', then this forum is certainly a waste of time....

You guys are damned quick on the draw to treat a 'new guy' like shit. The only part I'm new to is getting a ration of crap for asking a question.

 

[Scythian]

You want the exact details again in public instead of in the repeated PMs you've been firing off?

I addressed them to you to take the flame-war off line and not waste time here.

It's a type of internet etiquette.

That didn't work.

So, yeah, I'd like the public details....

 

[Scythian]

Did that answer your question?

Yes! That was a great answer!

Waaayyyy better than anything I found 'googling'

Thank you for your time.

 

[odot]

Ok, let me hijack this funny mess. Is there a way to ride to undo the cupping/rimming? A different style other then backwards? ( :lol: ) And is there a technique that we can relate to the cleaning of rings/cups around a toilet bowl?

 

[odot]

I expect a quick and lethal response to this.

 

[Thug]

Not sure about the dunny!

 

[yamaha1300rider]

I am not a techy on this site but here are my practical observations:

Cupping occurs because more mileage takes place with the bike upright than leaning over.

Yes the FJR is prone - difficult to get a sharp lean angle in poor weather conditions and high freeway riding

Irregular wear is, say, where one side of the tread wears more than the other

Now forget about cupping and just enjoy your ride!!

Finally, I agree that some people are welcomed with open arms and others lambasted when they ask questions - strange. I am surprised the Administrators don't jump on this at an early stage - probably don't want to upset long-standing members. Mind you it is sometimes instructive to look back to see whether the person asking the questions could have phrased them (and subsequent responses) more exactly and in a more friendly manner.

 

[sportryder]

hmmmm Very interesting thread. B)

Here's my .02c

Please take Warchild's response and display it as a sticky for anyone to read when they are wondering what "cupping" is. His response was highly accurate in every aspect.

Cupping or scalloping will never be eliminated if you are actually riding your motorcycle. If you are a cruiser that only straightlines it down the blvd then you might not ever see it. But, if you are riding the motorcycle and braking and accelerating at anything over "P" levels, then you are going to see the result as uneven tire wear.

Great post and response Warchild. It's the best one I've seen to date!

Cheers!