Rear tire worn out at 3600 miles: underinflation or something else?

[fratermus]

My first tire pressure check was when I got it home, then at the 600m service. I don't have the records in front of me (stranded at work) but I think the pressures were in the 36-38psi range. No pressure needed (assuming my air gauge is ok).

Last pic I had of the rear was Sept 21 at maybe 2000 miles:

I am a mild-mannered 190# rider and you can see my chicken strips are largely intact. I eyeballed the tire a couple of days ago and noticed the center of the tire flattening enough to notice from my commuting miles. I was going to start sniffing around for a harder-compound commuting tire.


Fast forward to my current emergency.

I believe I threw a strip of the tire on the way to work today at mile 3671:

It must have been close to work because it is not holding air now. The removed strip appears to go around the tire. {Edit: yes, those are steel belts in the pic}. No sign of interference with the underbits of the bike. No squishiness or imprecision in rear handling that would have tipped me off.

I am beginning to doubt my sanity and/or pressure gauge. It has admittedly been banging around in my tool box for years. Could I have been running it quite low unknowingly all along? I have been googling pics and it looks more like low pressure than anything else.

This is my first modern street tire (dual-sports before) so I don't know exactly what the wear should look like. But it looks like the tire has misshapen in the last few days. Bulgy in the middle, scooped at the edges where it stripped or wore off.

ARghhhh!

 

[Racenut]

36 psi would not be under inflated, certainly not enough to cause that. I'd see if the dealer can get any sort of leverage with the tire maker for a replacement. But don't expect them to just hand you a new tire. Replace it and see what they can sort out for the next time replacement.

Glad it didn't blow out, we might be having a very different conversation...

 

[fratermus]

No doubt. I'm sure it was very close to coming apart catastrophically. That would have been nasty.

I just went back and looked at the grooves on the edges in the first pic and on the bike now. I am convinced it was underinflated, possibly because my pen-type gauge has lost its mind so I didn't catch it. Or a more rapid deflation happened in the last couple of days (about 300 miles) and I didn't catch/feel it.

:-( Hopefully it can be a reminder to others to check their pressure (and gauges). It sucks to be the bad example.

 

[fratermus]

Hmmm, some stock Metz Roadtec failures on CTX700 that sound similar. Highlights/lowlights:

inspected tires and cleaned chain.went out for an hour
ride and when got back rear tire center torn off to the steel belt!

a work associate noticed that the steel cord was showing on the chain side of the tire, about 1 inch wide, all the way around...i had just gotten off interstate riding at about 80mph....2 days prior, i had just washed, waxed and lubed the chain, so im very sure the tire wasnt like that then...i prob put on maybe 300-500 miles on after the wash/lube.

(emphasis added)

I had just ridden about 50 miles and had gone to lunch when I met a new riding partner her husband was there and we were talking about the CTX when he noticed the steel was showing. I had not seen it this morning when I uncovered and did a check out. Must have been on the ground then. Looked exactly like LoneWoof's photos.

 

[Ed Up]

I'm thinking the recommended tire pressure is 36/42. If this is correct, you have been running low pressure even if your gauge is correct. I check mine about every other ride. If I'm on a trip running 400+ miles a day, I check it every morning. I got 8600 miles off the stock tire, bridgestone.

 

[670cc]

This looks like a tire manufacturing defect to me. If there are other examples of the same failure, as I believe you found, the NHTSA should be notified (assuming you live in the USA). This could be justification for a recall.

If you are a gentle rider, the typical wear-out of the Metzeler Z8 would be the center cords barely showing at about 8000-9000 miles, with little wear seen on the chicken strip area. The wear would not manifest as a missing chunk of ring as you displayed.

 

[Ed Up]

Looks like the belts have separated.

 

[fratermus]

Thanks for the input, everyone.

Bummed a ride home. Will load up the bike in the truck tomorrow AM and take it to the dealer before work. Will report back.

 

[maxwellian]

It really looks to me like some debris got wedged between tire and bike and scraped away the rubber in that area. It's carved away in a funny profile. Would probably show as damage in that plane on some part of the bike. Could be a defect though.

 

[fratermus]

It really looks to me like some debris got wedged between tire and bike and scraped away the rubber in that area. It's carved away in a funny profile. Would probably show as damage in that plane on some part of the bike. Could be a defect though.

I looked under the bike and there are no disturbances to the road grime that indicate physical contact from anything.

Maybe I hit something sharp and stationary that caused a slice there that peeled off. Dunno. I am intrigued by the similarity to damage report I pasted in above: "steel cord was showing on the chain side of the tire, about 1 inch wide, all the way around". Sounds exactly like mine. Of course, maybe it just means there is a spot on the bikes where stuff can get wedged and cause that kind of damage in that location.

 

[dduelin]

I'm not sure you said you weren't checking pressures on a regular basis or you were not checking them regularly.

I think it is important to check tire pressures at least weekly and like Ed Up said before any long ride. If the tire was underinflated for a while the repeated heat cycles each ride could have damaged the carcass and anything can or could have happened. Also you might have developed a slow leak and it all happened the last long ride. I'm about 175 lbs in riding gear and used 34-36F and 40-42R. Honda will tell you the rear tire should have been kept at 42 lbs all the time but that is for maximum vehicle gross weight at high speeds and legal department happiness.

Glad it wasn't any worse and we all get a reminder to check pressure. We only have two tires keeping us upright and in clean underwear.

 

[Deleted member 1183]

36psi is fine. I run that pressure on my NC nowadays and there is no issue. My KTM 950SM runs 34 psi as recommended by the factory. Again no issue. That groove in the left side of the tyre suggests to me also that something got caught between the tyre and the swingarm. I would be looking on top of the swingarm up front near the pivot point for any such evidence. If it was a low pressure issue then imho there should be a similar pattern of wear on the other side of the tyre.

 

[kharli]

id say you would know if the tyre was seriously underinflated ,it would feel plain weird and seriously low to flat sucks lots of power .

 

[hojo]

I think it's been said, 42 is ideal, and if your gauge reads low and your seeing 36, it could be 34 which is way low in my book. That being said, is there anything stuck up under neath causing the tire to rub, that looks like a very weird wear pattern on the left side....or a real bad tire.

 

[L.B.S.]

IMHO it's a defective tire. Note the bad batch of Dunlop Trailmax's that were OEM on the (2014??) NCX's. Many owners had them wear out like they were full on racing slicks.

The OEM Metzeler Z8's have compound diddled construction and fancy-shmancy gimmicks, and lots of other brands that advertize a mucked with blending of soft/medium/hard rubber along the profile of the tire carcass, have had bizarre wear results in a few examples over the years.

http://www.metzeler.com/site/com/products/tyres-catalogue/Roadtec-Z8-Interact.html

 

[what next]

The grove is only on the one side , it had nothing to do with inflation. Something got jammed in between frame and tire? I think you would have heard that. Tire alignment problem ?? I don't know if that would cause the grove that far off to the side. Interesting

 

[MZ5]

I've had this happen on non-motorcycles before. Happens more frequently on heavy trucks (not pickups). Tread separation, maybe belt separation since you said it won't hold air. Could be exacerbated by low pressure operation, but happens on its own lots of the time. Expect the dealer or tire manuf to claim that it was run at very low air pressure, that said low pressure caused the failure, and to deny any sort of responsibility or willingness to help with a replacement.

Unfortunate, but it happens. Maybe you'll be lucky and someone at the dealer or tire manf will help you at least partially toward replacement.

 

[L.B.S.]

The grove is only on the one side , it had nothing to do with inflation. Something got jammed in between frame and tire? I think you would have heard that. Tire alignment problem ?? I don't know if that would cause the grove that far off to the side. Interesting

I don't see a groove, so much as a delamination, or rubber peeled off/not properly amalgamated with the differing compounds or sections, from the inside out. I'm 100% suspect of strange wear patterns like this cropping up when everything about the construction of the tire points to exactly what that would look like:



Steel Radial
Innovative belt structure with a single ply of steel cords wrapped around a radial carcass at 0°. Patented high performance technology by Metzeler for both front and rear tyres.
Steel features a higher stiffness than textile and this allows the reduction of the tyre weight. Steel radial belt reduces the dynamic deformation of the tyre under centrifugal forces giving the tyre an excellent high-speed stability. Thanks to the more uniform heat distribution, mileage is increased and wear characteristics are more uniform.

Metzeler Advanced Winding
“Metzeler Advanced Winding” is a patented system for optimum spacing between the cords of the 0° steel belt. In certain sections of the tyre, the steel cords are wound with different spacing depending on the performance requirements on that particular area of the tyre. On both front & rear tyre the spacing is wider in the crown area for more elasticity and self-damping. For sections of the tyre used for mid lean, there is increased stiffness to support fast cornering. On the shoulder area on the rear tyre, the spacing is again wider for safe feedback and control when riding towards full lean.

Contour Modelling Technology
Advanced design technology of the tyre contour is tuned to meet high performance riding demanded on the latest bikes. A combination of different profiles on front and rear are optimised to be complimentary at any given angle of lean. The final contour design of the tyre set features the best aspects of performance for every riding style on all of the latest bikes: predictability, feedback at the limit of grip and cornering stability.

Interact: Multi-Zone-Tension
Multi Zone Tension
Modular steel cord winding tension: the performance of the tread compound depends on the stiffness of the structure underneath. Performance exactly where needed, giving maximum adaptability to different riding styles.

FCM - Fine Carbon Mix
Fine Carbon Mix compound structure. This new compound has been obtained using the last generation of high-performance raw materials for a quicker adaptability to a wider range of conditions, going from cold to warm, from wet to dry. This new structure ensures highest level of grip both in dry and in wet conditions, thus maintaining extremely high mileage characteristics.

 

[showkey]

I don't see a groove, so much as a

Sorry .......I only see very poor picture with lack of focus and no close ups or side views of the area in question.

Looks like it could be a mod gone wrong and something grooved the tire.........need way more info, to start talking defects.

 

[L.B.S.]

Sorry .......I only see very poor picture with lack of focus and no close ups or side views of the area in question.

Looks like it could be a mod gone wrong and something grooved the tire.........need way more info, to start talking defects.

If we are all speculating to begin with, I'm sticking with a bad tire well over a strange modification by the owner, doing this damage.

It beggars my belief than a mod gone wrong is more plausible than one of those gimmicky Multi Zone Tension radial belts at that *exact* spot, along with the dual compound rubber zone being right there as well, being the culprit.