Tire wear mystery

RedNigel

RedNigel

0
Joined
Jun 14, 2012
Messages
1,430
Location
Richardson, TX
Bike
2010 Red NT700
OK, bear with me and tell me if I am crazy
Last spring when I had to replace my rear PR3 at 7700 miles, it probably had some life left in it. The thing that put me over the edge was a 1MM strip around the entire tire and slightly offset to left of center that was worn ( or ripped) down to the cords.
I replaced the Michelin with a BT023 that soon developed the same 1MM strip in the exact same place. (queer, huh?)
After many visual inspections that never gave me anything to blame on the bike, this afternoon I finally saw something that maybe could be the culprit...maybe

Where the swing arm begins...right where the driveshaft housing begins and the swing arm crosses the bike...approximately in the middle of the swing arm, there is a small hole. Something was wedged into that hole and protruding from it. I am guessing a small rock. When I dislodged the object it fell into the swing arm.
I can't say for sure, but I think it may have lined up with the 1MM groove on the tire.
The only problem I have with this theory is that the swing arm is a long way from the tire.
The pebble was only sticking out maybe a 16th or 8th of an inch at best
Is it possible that at speed the center of the tire expands enough to come within an 8th of an inch of the swingarm?????

The only way I will know if I am right is if the groove in the tire wears itself out as the miles go by
I just don't see how two tires from two makers could have the same problem
 
There is some tire growth but it's fairly small and not enough to cause the tire to rub on the center bridge of the swingarm. And I'm presuming you had fitted the correct size tires or did you opt for one that was taller?
 
It sure sounds to me like your tire(s) were rubbing on something - possibly when the suspension is compressed. There isn't much diameter growth with rpm.

OR

Maybe there are little gremlins inside your swingarm that poke the object out that hole when you're not looking.

Anyway, if you keep looking, I'm sure you'll find the cause unless the protursion has borken off and the problem is gone. Was there any problem with the original tire? Good luck.
 
I HAD THE SAME ISSUE WITH MY PR3's!! I was kind of embarrased to menthion it on this site as it seemed as if I did not check my tires enough. I check my tread wear pretty often and air them up if needed about once a month. I have about 8000 miles on the tires and noticed when I put the bike to bed for the winter I was down to threads on the left side of my rear tire. Looked like normal wear to me as opposed to something lodged in the swing arm scraping away at the tire. I do have a pretty twisty commute and given where I live I am not going straight for long periods of time and using the sides of my tire for sure. I was guessing it was because those tires have softer compounds on the cornering side for traction and harder compounds in the center where it spends most of its time for longer wear. I was a little baffled as to why just the left, do I feel more comfortable in left turns and do them more aggressivly? Maybe a design flaw in the rubber or tire manufacture? Anyway I would really like to know why this has happened. I love my PR3s and it will not keep me from getting that brand again but it seems it got down to threads rather fast (not milage, but time ridden between tire inspections).
Any one else out there with that problem?
 
High Crowned, High Speed, Texas heat and Texas Chip Seal, will wear fast and do funny things with Motorcycle tires. I got 11 years in Wichita Falls to prove it. Here in Colorado my Moto tires are lasting on average 2000 miles longer. Same bike, Same rider. Different place. Of course now I spend a lot of the riding time on the outer edges of the tire, not just the middle.
 
My thread is not at all about uneven or premature wear
I am talking about a groove being cut into two consecutive rear tires of different manufacture, as if a knife tip is being held against the tire while I ride
About a 1MM groove that will cause me to replace my tire before its time
And I cant find the cause
 
RedNigel said:
My thread is not at all about uneven or premature wear
I am talking about a groove being cut into two consecutive rear tires of different manufacture, as if a knife tip is being held against the tire while I ride
About a 1MM groove that will cause me to replace my tire before its time
And I cant find the cause
Click to expand...

How about a picture?

I don't know the NT well at all, but maybe the action of the swingarm moving up is touching something in the fender under the seat area? There's no way the tire would expand enough to touch a small pebble from what you describe.

Is the groove all the way around the tire or just a small section?
 
Someone wanted pictures of my worn out PR3 tires. So here is a tire mileage comparison.

First picture: Front PR3 with 13,747 miles on it compared to a brand new one.

Second picture: Rear PR3 with 11,606 miles on it, compared to a new tire.

The bike has 116000 miles on it with all original suspension.

The line you are talking about might be a mold line, I have seen them before, How ever I checked my PR3s tires on my ST and NT and don't see it yet. Also here are a couple of pictures af my last PR3s off of my ST1300.

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Thats the exact seam I am talking about, except mine is an open groove on the Bridgestone and became an open wound on the Michelin, exposing cords
A qualifier on the PR3...
When I realized the groove had become a safety concern, the center rain sipes were all but gone. You had to look real hard to find a hint of where they used to be, so that tire was probably worn slap out anyway
But it bothers me this seam/groove is open on my Bridgestone
 
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I just looked at my new set of PR3s, they each have two colored lines on them and a faint line in the center as shown above. Did you add any thing under the seat and used a long screw etc and when you sit on your bike it hits the tire. I know it is hard to see up into the fender well, try putting a rag on your tire, sit on the bike and have somone turn the wheel and it should catch if there is some thing there.
 
One thought I had was a defect in the tire where the 2 tread compounds meet. Some kind of separation of the center compound from the sidewall compound.
Of course that doesn't add up since you had 2 tires from 2 manufacturers. It leads back to something cutting into the tire. But what?
Good luck, I would be a little paranoid about tires by now.

Brad
 
I am also at a loss for an explanation. My tyres wear more on the left side because our roads have fairly high crowns. An engineer friend said that one should always look at what was done last. In this case he changed to a Pr3 and then to a Bridgestone. Was something left hanging in the fender well? Since he cannot see everything inside the fender, would it be possible to clean the tyre and tape the offending groove with masking tape--then ride the bike slowly for a short distance and see if something scribed the tape.
 
Sailariel said:
Was something left hanging in the fender well?
Click to expand...

I have since ben able to get a good look all up in the fenderwell. There is nothing hanging, so the only way the bike could be damaging the tire is if my suspension is bottoming out on a regular basis and rubbing on one of the thin ridges one sees in the well
I weigh 220#, which I don't see as a problem
I keep the preload at or above the factory default which is 11, but never higher than 13-14
 
Do you have pictures of the tire(s).

I'd be very suspicious of two different tires from two different manufactures wearing with the same groove. Sure doesn't sound like a tire "defect" is likely. Most seams I've seen on tires run horizontally and I've had a few open up on me.

Can you paint the inside of the groove with some white paint to see if the groove is actively being trenched out?
 
REDNIGEL:
This may be some thing to look at. Put the NT on the side stand and check the center stand to see if every thing is clear. Then do the same for the side stand. Maybe there is a bolt backing out. ?

Using the rag trick I though if you had a piece of fender broken off and hitting the tire it might show that, but you said you could see all around the fender well. I think I would try the rag trick just for S&G.

Just grabing at straws at this point. This is a tuff one.
 
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I know the seam on the Michelin is a factory thing, and I am assuming the seam on the Bridgestone is too
I just don't like them opening up like they have on both tires
I am 99% sure there is nothing wrong with the bike
 
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