RiderForums.com - Kawasaki Motorcycle Forum banner

1 - 18 of 18 Posts

·
Wheelie for Safety
Joined
·
1,550 Posts
Discussion Starter #1
I have about 2,500 miles on my ZR-7S now. I just noticed that my rear tire is cupping real bad. The front one is also doing it, but not as bad. I only ride my bike in the mountains and I do brake rear hard at times.

Has anyone else had this problem?

Andy
 

·
Dirty Harry.... Moderator
Joined
·
9,816 Posts
I'm not sure of what you mean by "cupping" -- does the rear tire look like the front tire of a cage with a bad alignment or brake problem? or a badly balanced cage tire? I've heard of problems with motorcycles being out of alignment. Maybe from a chain adjustment. I seem to remember a thread regarding some type of line adjustment for a MC. Hope somebody else has some definitive info for you. Tom
 

·
Registered
Joined
·
214 Posts
Andy:

Either slow down in the turns or when you replace your tires, get some more suited for your "carving fetish"

CUPPING:
Cupping, which is more accurately described as scalloping, is a natural wear pattern on motorcycle tires and it will always follow the tread pattern. It is not a sign that you have bad suspension parts. It merely shows that your tire is indeed gripping the road when you make turns. This scalloping takes place within the side wear bands of a leaned motorcycle. The extreme forces that come in to play when the bike is leaned in a turn are what produce the effect and when the wear becomes sufficient, one will experience vibration and noise when one banks into a turn on a scalloped tire. The leading edge of the tread grips the road and the rubber is scuffed off the tire in that area causing a depression. As the tire rotates, the pressure moves to the trailing edge of the tread pattern and the tire flexes there which causes less scuffing so less material is ground off the tire. The more complex the tread pattern, the more complex the scalloping pattern will be. The softer the compound of the tire, the sooner this scalloping will become evident. Radial tires are more prone to cupping than are bias ply because the compound of radials is more often softer. Improper balance has nothing to do with "cupping" on a motorcycle tire. Improper balance will merely cause your bike to vibrate at speed. Low tire pressure will exacerbate this wear pattern and you will lose many servicable miles by running low. Check pressure often.
 

·
MotoMacGyver
Joined
·
2,546 Posts
Yeah Andy, both my set of tires did it. My stock Dunlop D205's did it, and now my Bridgestone BT 020's are starting to do it too.

However, I noticed that the more you lean, the less it does it. Or the rubber wears like it should. I say this because I lean a lot more to my right (and hang off more) than I do my left. It's simply a mental thing with me (yes, I AM mental, but that's another story). I'm just more comfortable leaning right than left. The left side of my front tire is showing slight signs of cupping, but not my right.

What I don't like (but it's unavoidable I guess) is the front tire morphs into a "house/roof" shape over time. It's still "pointy" in the middle, then it's quite flat (not curved like when new) on the sides, then goes back to the "normal" shap back at the sidewall. From turning I guess. The only way to round it out even more is to lean farther and farther I suppose.

Yep. That's my mission. To ride the snot out of the bike in the twisties merely in the interest of keeping a proper tire profile. :D

Emrah
 

·
Dirty Harry.... Moderator
Joined
·
9,816 Posts
Emrah, let me guess...your'e not going to be a tire guy in NASCAR? Right? Just kiddin' ya man, turn them wrenches and make those cars run fast. Hope to see you in the garage or on pit road soon, somewhere in NC. Tom :smilewink
 

·
West Coast Moderator
Joined
·
12,996 Posts
Not that your tires are running low on pressure (I can't say, I don't know), but I would like to repeat the part about low tire pressure. Cupping will be alot worse when tire pressures are low. Some folks like to run lower pressures when riding the twisties and that's great for traction, but it really takes it's toll. Not only on the tread, but it breaks down the sidewalls alot faster. I've seen tires that looked good on tread, but the sidewalls were broke down to the point that the tire was essentially wore out.
 

·
Wheelie for Safety
Joined
·
1,550 Posts
Discussion Starter #7
Thanks for the info everyone. :)

I'm not changing my riding habits, so it looks like I'll need to get a new rear tire every 2,500 miles.

Now to do some research on which tire scallops the least. I'll look for one with the fewest rain grooves.

Andy
 

·
MotoMacGyver
Joined
·
2,546 Posts
I must have misread your first post and problem. You're cupping the REAR tire? Mine just squares off from commuting too much, and gets the normal wear and tear on the sides. I haven't noticed cupping on my rear, only in the front.

What tires do you have? The Dunlops or Bridgestones? I got about 5500 miles out of my D205's, and I'm about 4000 or 4500 on my BT 020's. I ask this because I absolutely LOVE these
BT 020's. This is my opinion on my riding and my feel, but they offer WAY better grip than the Dunlops, much smoother ride (don't notice it hooking up and wallowing in the rain grooves on my daily I-10 commute), and they seem to be wearing much, much, much better than the Dunlops did. Like I said, I've had them on for about 4500 miles and they only look about 1/2 to 2/3rds worn.

Might be an economical choice for you if you don't have them already.

Emrah
 

·
Wheelie for Safety
Joined
·
1,550 Posts
Discussion Starter #10
Hi Emrah,

The 2001 ZR-7S comes with Bridgestone BT 020's. They are nice tires except they cup too easy. Others who ride the same mountain I do have the same problem.

I think I'm going to try the Metzler Rennsport. They are expensive, but they resist cupping and will handle better.



Andy
 

·
MotoMacGyver
Joined
·
2,546 Posts
Aren't those a really sporty tire? I realize that most of your riding is twisty stuff and not commuting, but I was just suggesting a more "street" oriented tire (read: longer lasting) to get more mileage out of them. I'd certainly like to hear a report on how they are if you do get them though. I'd love to put a super-sticky tire on mine (Rennsports, Pirelli Corsa's, Michelin Pilot Race, etc.) if I didn't rack up so many miles. It's expensive as it is!

Emrah
 

·
Wheelie for Safety
Joined
·
1,550 Posts
Discussion Starter #12
My tires have plenty of tread left, but they are cupped so bad that I'm loosing traction. So I figure if a get a tire that is designed for sport riding (less rain grooves) then they will not cup and I will get more miles out of them.

Andy
 

·
Registered
Joined
·
214 Posts
Andy,

I think it is great that your cupping your back tire. That tire is "non-living" proof that sport riding is 90% rider and 10% bike. We all have friends on R1's and Jixer's and I am willing to bet that not many of them are looking to replace a tire at 2,500 miles. The ZR is a very capable bike in the right hands.

If your looking at Mez's, this is what motorcycle.com says in a review about one line they tested. The tires may be race oriented but the review sure makes a case for them in a street application as hard as your ride.

http://www.motorcycle.com/mo/mcbeware/mez1.html
 

·
The Deer Slayer
Joined
·
7,382 Posts
Hey Andy. I'd go for the Metzeler's. When I replaced mine I went for the ME Z4's, similar to Renn's. The 4's are more a sport touring tire. I can tell you this, though. The pattern on these tires works well, and for what it's worth, they lend a great sport look to the whole bike. You wouldn't think a tire could change the look of a bike simply by it's tread, but it does.

Have you upped the suspention front or rear ? If so, the Renn Sports should really transform your ride. The ZR just soaks up all the little upgrades so well. You could go on forever, I think, that is, if it's your cupped of tea. (please hit laugh-track button if available). Anyhow, those tires look smokin'. I'd love to know how well they work for you.

Tony
 

·
Silver Member
Joined
·
881 Posts
Having run on all types of tyres in the past, I think ( with the risk of being shot ) I just prefer euro tyres.

The Pirellis on my ZX6E/ZZR600 were great, and after running thru the original Bridgestones I now run Michelins on the ZR-7.
For some reason they tend to get a similar grip to the Japanese tyres and yet run a harder compound.

Maybe the tyres designed for low(ish) HP, heavy bikes like Guzzis, BMW's and older Ducatis just work well on the ZR-7.

Anyway I run Pilot Sport Front and Macadam 100X rear. Good combo.

REAR:


FRONT:


:)
 

·
Wheelie for Safety
Joined
·
1,550 Posts
Discussion Starter #16
Emrah, you were correct, I looked at the Metzeler Rennsport and they are more suited for the race track.

Others have recomended the Metzeler Sportec M-1 and they look like good.





Martin, your correct I most likely did run low tire pressure to accelerate the cupping.

Thanks for the tips Tony and Mike, I'll take a close look at those tires as well.

Andy
 

·
The Deer Slayer
Joined
·
7,382 Posts
Hey Andy, is the Metzeler company paying you a commission?:laugh:

I'm sold. You give us all the confidence to hang off in those turns too. Yes, this is a sport bike, thank you.

Tony
 

·
Registered
Joined
·
85 Posts
All I can say is that my original Dunlop 205's were "cupped" really bad and I just had them replaced with another set of 205's and my ZR handles completely awesome now.
 
1 - 18 of 18 Posts
Top