Problem with a Khumo Runflat tire

[vanavyman]

   Looking for some advise on a new car tire and what I could have done wrong that ruined this one.  This tire is about 2 years old and has approx. 10,000 miles.  I researched on this blog quite a bit and asked a few questions before buying this tire for the rear of my 99 Interstate.  Have a Michelin Alpine Runflat on my 05 Wing and love it.  It has about 30,000 miles on it and looks great.  From my research I'd come to the idea that 28-34lbs was the right range to run the Khumo so that is what I have done.  Lower when just me and higher when 2up pulling my Bushtec trailer. I have a tire monitoring system so I was aware of the tire pressure most of the time.  It seems that the edge of the tire was worn out from low air pressure.  Do you think that was too low of air pressure?
  Had a Dunlap tire put on at the Honda dealer while out of town and now I'm trying to decide what to use going forward.  I want to use the safest tire and I thought that would be a Runflat not worrying about the cost.  I've talked to a few guys that run car tires for the performance and they run soft rubber for sticking in the corners.  I've looked at the Taxi tire and like the looks and that it is a little taller.
  Any suggestions on what would be the safer tires to run?  We ride most of the time 2 up in the mountains besides me using it back and forth to work a little.



Thanks,

Dan

[Chrisj CMA]

That separation looks so surgical, could it have been cut by a bolt under the fender?

Tread separation happens, it's my understanding that heat caused by under inflation is the usual culprit but it's not unheard of for a tire to just let go like that

[pancho]

Sort of looks like you got onto the nut cage...? Are they still on the bike? I see plenty of beads in that tire,, bet it rode nice.

Everyone I have heard, myself included, that run a car tire, run much higher pressure than you did.

[vanavyman]

I will have to double check on the nut cage to see if they are still there.  I've been using the beads since Bon S gave me the name of a company to buy a quart of them for around $40 a few years ago.  I've used them on all my bikes since and they ride nice.  This is the info he sent me:
"'Quackenbush Co, Inc. at www.Quackco.com. They are QBZ-58A, 0.8mm beads. I don't think you can order on line so their phone is 815.479.8900. Their email is Quackco@mc.net.  The only downside that I've found is that you need to be near an air hose if you're going to check the air pressure. A single bead can lodge in the Schrader valve and let it leak after using a gauge. It takes a puff of compressed air to dislodge the bead. You can read all about this at InnovativeBalancing.com."  I've been putting 2oz in the front and 3oz in the back.

Dan

[John Schmidt]

First, to prevent a bead from blocking the valve stem I always check the pressure with the valve away from the bottom. As for the damage, one of two things or a combo of both; low pressure, much too low, and second is the possibility the nut cage did it. That's usually where you'll experience contact and if it's only on the right side then my guess is the nut cage. But never run it with that low a pressure, it flexes way too much and wallows in the turns. Put it up to at least 36 and leave it, some run it even higher.

[mark81]

The way the belts are hanging out leads me to believe it was a tire defect. Only other possibility would be you riding with 0 pressure for quite a while. Was it holding pressure when you removed it?

[vanavyman]

While riding in the mountains 2up pulling a 300lb+ trailer it started to feel weird.  Stopped and looked / felt the tire.  It did not feel flat, but from my monitor said it held full air.  I only felt about 1/2 of the tire.  Decided to head to the Honda dealer which was 30 miles away.  Got 5-6 miles and heard a pop and all the air came out quick.  Rode it for 5-6 more miles without air to get to a safe place off the mountain road to pull over and call for a tow. 

Dan

[old2soon]

If the inside of the tire is not bubbly-technical term-another words still smooth on the inside-PERHAPS the issue was not due to low inflation and heat related. Just from that photo SOMETHING got into that area and caused the damage. If the nut cage is still there and it is nice and shiny-like polished-you may have found the culprit. I'm on the Austone Taxi tire and of all the D/S tires I've run-this one IS The best of the lot. Siting on the bike which side was the damage on the tire-right or left? RIDE SAFE.

[The emperor has no clothes]

I've not run a run flat tire, so I have no knowledge there. But I've had 5 car tires now and 4 of them different. I run them at from 34-38 lbs. depending on the circumstances. Like the others I think it must have been the nutcage. I've been hesitant of the run flats because it seems they work best when they flex in the turns. It seems the stiff sidewalls would be counter to that.

[TJ]

I see a lot of remarks from people who don't run run flat tires...  28 to 34 should be great for that
Michelin tire .. that's the pressure most G/W riders use and I've been running that for years
and never had that happen... looks like nut cage got to it...  also what setting do you use ridding two up???

PS: I'm running a Kumho RF now on my I/S and real happy with it...

[Gavin_Sons]

My bet is on the nut cage, or if the mod has been done the square nut that goes in the nut cage. If the bolt is too long then the bolt could have got it. Only way to be sure is to get a shoulder bolt and run it from the inside out and use a nut to secure it on your strut. Hope you find the problem