Bicycle Mechanics - TIRE has an egg!

Just replaced a tube in my rear tire with a new tube. The rim is essentially perfectly true.

The tube was well centered in the tire. I blew it up a little, and set it in the tire and made sure it was uniform all around with no redundant regions. I made sure the beads were set. Kept blowing it up a little bit at a time and rechecking everything. When I blew it up all the way it has a pretty good egg. Maybe 7-8 mm.

What gives?

Is there such a thing as tire fatigue?

sounds like the cords/belt are breaking inside the tire. had a tire fail with busted cords while headed to work, called work for a pick up

Casing failure, replace ASAP.

If you must ride on it, reduce the pressure to the point where the rim is still supported off the pavement and carefully ride to your LBS and buy a new tire.

I'm afraid you broke some casing threads while replacing the tube. Did you perhaps use a screwdriver to pry the tire off the rim?

Theoretically, it might be possible to glue a boot in, but as a practical matter, the tire must be replaced.

What's a "redundant region"?????

photo?

A static photo wouldn't help.

After putting the tire back on, with the bike on the repair stand, and getting it spinning, you can see it's not round. No side-to-side wobble but up and down.

Redundant meaning the tube was not stretched in any part of the circumference and lax in another part of the circumference.

A static photo wouldn't help.

After putting the tire back on, with the bike on the repair stand, and getting it spinning, you can see it's not round. No side-to-side wobble but up and down.

Redundant meaning the tube was not stretched in any part of the circumference and lax in another part of the circumference.

If the bead is even all the way around the rim (there's a molded-in line on the tire that will show this) and the top of the tire is bulging... yep, the tire casing is failing. Replace it before it goes boom.

OK, as the others have said an "egg" or well defined bulge in the wire means the cords are broken, or separating allowing one area to be stretched by the pressure.

However, if you have a radial high spot, and it's over a section of more than 4 or 5 inches, it's more likely a seating problem. As jeff Wills said, there are molded lines along the bead of the tire. Find the one nearest the rim and see that it stays the same distance from the rim's lip when the wheel is spun slowly. Check both sides. If the lip changes distance, especially if it moves out the same place as your egg, than it's simply a case of poor seating, which most commonly happens ear the valve.

If the bead indicator line is concentric, and the tire bulges than the tire is truly shot.

i suppose the first thing i would do would be to put the front tire on the back and take a look. if I still had an "egg" i'd look at the rim, if i didn't have an "egg" i'd throw away that old rear tire and buy a new one most likely.

I hear the garbage can calling

How was the tire before you had the flat?

Before running out to buy a new tire, try this:
1. Deflate your tire to about 10 psi.
2. Push straight in on the valve stem.
3. Reinflate the tire to operating pressure and see what happens.

The area of the tube around the valve stem is thicker than the rest of the tube. That thick area can get caught under the tire bead and lift that portion of the tire up a skosh.

The moulded line is pretty straight all around on both sides of the tire.

The area around the valve is OK too.

It's actually up and down in several places around the tire, not just a single egg.

I think the problem is as follows:

This is a Panarcer Pacella 700 x 35 mm tire that is listed on the tire itself as having a max pressure of 90 PSI.

The specs on the Nashbar website list it as having a max pressure of 75 PSI.

I've been running it at 85 PSI that is probably too high, and it's stretched out.

I carefully inspected it and don't see any broken nylon strands on the inside but do see some cracking in the rubber on the outside.

The front tire is the OEM 1990's Heng Shin that is also starting to crack.

Time for new pair of tires I guess. I was thinking Vittoria Randonneur Road Tire but they're a little pricey.

Any suggestions or comments?

Thanks for the input!

How was the tire before you had the flat?

Before running out to buy a new tire, try this:
1. Deflate your tire to about 10 psi.
2. Push straight in on the valve stem.
3. Reinflate the tire to operating pressure and see what happens.

The area of the tube around the valve stem is thicker than the rest of the tube. That thick area can get caught under the tire bead and lift that portion of the tire up a skosh.

Actually I replaced the tire on a new wheel. The old wheel was so far out of true that the tire issue was masked.

I had a horrid bulge last year on my Schwinn Cruiser SS.

Oddly enough is was a brand new 26x2.125 whitewall with wonderful knobs. I sorta know but sorta don't know!

The moulded line is pretty straight all around on both sides of the tire.

The area around the valve is OK too.

It's actually up and down in several places around the tire, not just a single egg.

I think the problem is as follows:

This is a Panaracer Pasela 700 x 35 mm tire that is listed on the tire itself as having a max pressure of 90 PSI.

The specs on the Nashbar website list it as having a max pressure of 75 PSI.

I've been running it at 85 PSI that is probably too high, and it's stretched out.

I carefully inspected it and don't see any broken nylon strands on the inside but do see some cracking in the rubber on the outside.

The front tire is the OEM 1990's Cheng Shin that is also starting to crack.

Time for new pair of tires I guess. I was thinking Vittoria Randonneur Road Tire but they're a little pricey.

Any suggestions or comments?

Thanks for the input!

10psi over the nominal rating shouldn't create the problem you describe. I routinely run my 90psi tires at 110psi without issues or undue wear. I think you got a defective tire there.

The Vittoria Randonneur 700 x 32 or 700 x 35 would be a good, tough tire: http://www.biketiresdirect.com/product/vittoria-randonneur-tire . It's going to be somewhat heavier than the Pasela, though.

After consideration I decided to go for the Nashbar brand 700c X 35 mm 'comfort' tire:

http://www.nashbar.com/bikes/Product_10053_10052_174913_-1_202642_10000_

I won't be using it on my next Tour de France but given the bike it's on I thought it was an appropriate compromise.