Mountain Biking - I've had pinch flats before, but damn...

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joetronic
04-26-09, 06:18 AM
http://img.photobucket.com/albums/v140/jmadams/P24190110tire.jpg
http://img.photobucket.com/albums/v140/jmadams/P24190128tire.jpg
http://img.photobucket.com/albums/v140/jmadams/P24190149tire.jpg


Okay, heres the story...

Kenda K-rads, 2.3. Filled to 45psi.

Been filled for a few days, and had a few hard urban rides. Bike was hanging in living room all day friday. Not riding, tire not even touching the ground. Was watch the tube, and dog walks by bike, but doesn't touch it. And BANG!!!!!! just blew. Knocking whole rack over, two bikes falling to the ground.

Why I'm even posting this you say? I could understand that blowout if I was riding. Landing hard or clipped rear wheel on something hard as this is a lower psi, but I wasn't even riding it. And it was ridden pretty damn hard the three days before after checking psi. Why would it just blow out of nowhere? My thinking is the tube was pinched, and the vibrations of the dog walking by (small dog, and stand is stable. Even when I walk by, or get bike off top of rack, it doesn't wiggle) caused the tube to give way. As you can see, the tire separated from the bead, and tore through all layers of the tire. I'm puzzled. Inspected the rim, and that looks fine, so I don't think anything was caused by that.

I did look at the front. And there are places where the tire and bead look like its a weak bond, but that may be all in my head, as I've never noticed that before while changing tubes and whatnot. I do not use anything but tire levers to pull the bead. That would be another explanation for it separating like this if I used a screwdriver or a nail (I know, but I've seen it done) or something like that.


Canker
04-26-09, 09:42 AM
Kind of had the same thing happen though not as violent. Had my bike parked in a rack outside work and walked outside hours later to take a break and heard the tube blow. Just weird timing.

DirtPedalerB
04-26-09, 01:50 PM
I've seen older tires do this ... I suspect the tire was defective or dry rotted.


ed
04-26-09, 01:51 PM
Yeah man...how old was it? Did it sit in the sun for a long time?

joetronic
04-26-09, 07:14 PM
About 2 months. Not old, no prolonged UV. No sings of dry rot. Ordered from Jenson, so I doubt it was sitting around long in warehouse.

ed
04-26-09, 07:46 PM
Looks like you need to call Kenda and ask for Warren T.

prathmann
04-26-09, 07:51 PM
Another thing to check is the position of your brake pads. Make sure they can't come in contact with the tire even when the wheel rotation is pushing them forward.

Dannihilator
04-26-09, 09:06 PM
Not a brake related issue. Looks like a defect in the tire, weak spot in the sidewall and just today it gave way.

kr32
04-27-09, 03:53 AM
Had the same thing happen to me with roadbike tire. Sitting watching the TV and I thought someone shot a gun or something. I had fixed a flat earlier in the day. I have no clue why it happened either. Just bought a new tire and tube and kept on getting on.

joetronic
04-27-09, 08:23 AM
Looks like you need to call Kenda and ask for Warren T.

I thought about that. I called jenson, and they gave me a few numbers to try. I'm not looking to get anything out of it, just to let them know. Jenson said they can replace the tire, or I can get store credit. Probably gonna use the credit to get a bunch of tubes or whatever.


OTOH, I'm thinking to running a intense MK in the rear, and keeping the other k-rad out front. Just mounted it, and gonna give it a go at the jumps today.