Bulging Tube?

[Penny4]

About 6 miles into my ride today, I suddenly felt the back wheel rubbing. I figured it was the brake pad rubbing on the tire, but when i stopped and looked, the tube was bulging between the tire and rim.

What would cause this?

It's a 23 cc tire, and only about a year old, with not a ton of miles on it. The LBS put the tire on the rim for me, and I've never had to take it off to replace a tube or anything.
I haven't ridden my bike in about 2 months, and the tire was almost flat this morning, as I apparently had left the valve open. (The front was still pretty full though.) I filled it to about 115psi, which is what I usually ride at.

I deflated the tube and re-installed it while riding. When i got home, i decided to check it one more time. When i took the tire off, I saw a section of the bead separated from tire. Well, maybe not the bead itself, I'm not sure, but the bead was exposed, and whatever is on top of it was peeling away. I'm assuming this is what caused the tube to start bulging.

Just a faulty tire? It was a Michelin Pro 3 (or something like that), so a decent tire.

[pll]

I have no idea why that would happen, but replace both the tire and the tube. The tire has failed and the tube has been stressed and might fail in a future ride (or by itself). That happened to me after I had a tire replaced at a bike shop -- the tube bulged. I deflated, set it correctly, re-inflated. A week or so later, the tube just went flat.

[Skippyak]

How many miles on the tire? How long would you expect a tire to last? Is 115 the recommended PSI for you? That seems high (depends on your weight too, but I don;t bother with over 100). http://www.competitivecyclist.com/re...-tire_671.html check out the PIS info here. Have you ever read the PSI ranges on the tire wall?

[OakLeaf]

It might have been a bad tire or it might just have been an *old* tire. Tire compound deteriorates over time whether it's being ridden or not. It's a year old to you, but how long since it was manufactured? Some brands have a date code the way motor vehicle tires have to. I'm not sure about Michelins.

Depending on your weight and the condition of your road, you might be able to get away with slightly lower tire pressure, but 115 certainly isn't enough to make the bead separate. I'd guess it would take more like 150 to do that, *way* over recommended pressure. I've had it happen, but that was when I was a kid and filled my tires with the gas station compressor without a gauge, then parked the bike in the hot sun all day.

[Penny4]

Yes, i did buy a new tire today, and put a new tube in also. The tire probably had less than 1000 miles on it, so not a lot of wear at all. The max psi on the tire is 116, and based on my weight, I usually fill all the way. Perhaps i overinflated today but I'm not sure why the bead was partially exposed.
My little planned 1 hour ride turned into an all day event!