I was checking the front tire on my 2012 ZX-14R. On the left side of the tire about 1/2 inch off center there are little bumps all the way around the tire, spaced about 4 inches apart. Anyone know what caused this? It's the stock Metzler. About 5,400 miles. Thanks for any help.

My stocker did something similar to that, as a lot of people have said with the OEM metzlers,
I went with a PR4, even though its a higher mileage tire, it is much better as far as grip

1. Low tire pressure.
2. Balance.
3. Curvature of the roadway.
4. Worn when 'steps' are showing even though the throwaway indicator marks are still deep.

Thanks for the answers. The tire pressure has always been 40-42 lbs. These are little bumps that almost look like bubbles. I'm glad I caught it now, before spring. Maybe this was a problem with the stock Metzlers. Before I parked it for the winter, I raced a friend of mine that has a 2014 Hayabusa. I took the bike up to about 180. Won't do that again until I get a new tire.
Just so you know, I smoked the busa. My friend said the faster we went, the faster I pulled away.

* Last updated by: mokaw on 1/25/2016 @ 2:11 PM *

Can you post a picture of the issue?

Vic, I don't know if they would show up on a picture. I didn't even know they were there until I ran my hand around the tire. I could feel them plain as day, but they're hard to see.

Sounds like cupping, basically what hub is describing. It happens for many reasons as hub is describing. Usually it's not too much to be concerned about unless it's severe and deeply pronounced and prematurely wearing your tires out. You've got 5400 miles on your tires. Most likley they're about done anyway, I'd guess you'd at best have around 25%. You have gotten tremendous mileage out of those tires.

It's normal for some wear imperfections to develop and start to show. Could be a matter of roads, air pressure, suspension tune, riding style, etc, but no matter what most likely when you're tires get near their end of life these sort of things will become more pronounced.

In the case of severe cupping most likely some kind of adjustment needs done because the suspension is not maintaining enough control. Might be springs, damping, geometry, or other things. But this would be indicative of failed or broken components. For example having no fork oil resulting in no damping.

Good luck be sure to let us know what tires you put on next and how you like them. Mine came with M5s too, thought they had great traction but then very heavy steering (lot of effort to turn) which I didn't care for.

I don't know about a suspension variable? Seems they were cupping with just zero adjustments back in the day. I wonder if a bicycle has the same cupping and that's zero suspension we see the same phenom. Also seems weird that the cupping is uniform as in; equal distance from each other and all the way around. I can't explain it...

Tried to post 4 times. None worked. Keeps saying error occurred. Did this work?

Did this work?

NOPE. You click the 5th icon from the left on top of the box where you post messages. Looks like a photo with a + sign in the lower RH corner.

A menu will appear and you choose the picture file from your desktop or where've you have it on your computer.

Then click UPLOAD.

Then the pic will appear in your photo briefcase so you can click it to make its code appear in your message. Now the pic will show when you post your message.

Access the pic anytime you want to post it by clicking the briefcase icon, 6th from the left.

I don't know about a suspension variable? Seems they were cupping with just zero adjustments back in the day. I wonder if a bicycle has the same cupping and that's zero suspension we see the same phenom. Also seems weird that the cupping is uniform as in; equal distance from each other and all the way around. I can't explain it...

Some claim cupping can be read and remedied with suspension adjustments. I've noticed the last 25% of tread of my rear tires have had some cupping on the rear edge of the sipe in the edge tread. In my case, this is something that isn't noticeable until the tire's are wore out so it's not anything I'm concerned about. If it was cupped like this after 500 miles, something definitely would be amiss.

The theory is based on the tire pogoing which is why it's considered a control failure.

My Metzlers cupped with not many miles on them, got the PR4's and did not adjust the suspension,
and after many miles, no cupping, the metzlers that came stock were trash IMHO, at least the ones
I got on my bike, but as stated before, ALOT of people on the internet have had cupping problems
with the OEM metzlers.

after putting a set of PR4's with a 55 rear, it felt like a new bike, turned in a lot quicker
because of the 55, but also gripped a lot better, even though they are known as high mileage tires

My only guess is that the Metzler on my bike is a lousy, defective tire. I agree with carabuser, and thanks to his advice, I ordered a set of PR4's. Living in North Dakota, it will be a while before I can check them out.
Thanks Vic, Hub, carabuser, Rook, for sharing your knowledge and advice.
And Hub, I think I told you before and I'll tell you again. Sometimes what you say is WAY over my head. You have so much knowledge in that head of yours and I don't understand some of the technical things you've explained on other threads. Very, very smart man. Thanks again carabuser for bringing up the PR4's.

* Last updated by: mokaw on 1/27/2016 @ 10:40 AM *

I don't understand some of the technical things you've explained on other threads.