Deformed Tire
 

I was taking a little rest today on my ride and noticed this deformity on my rear tire. When I got home I removed it, checked for any crimping of the tube, didn't find anything, put it back on and the same thing, in the same place on the tire, different placement of the tube in the tire and different placement on the rim. Seams like a soft spot on the tire.
https://cimg9.ibsrv.net/gimg/bikefor...036a61ce5a.jpg

What's it look like at the bead seat?

I had a tire do that before ultimately bursting, thankfully not while I was riding. I was not too thrilled, to say the least...

You sure the tube isn't too big and wrinkled up inside? Otherwise, if the witness line is even all around, then I say you got a bad tire.

If I couldn't return it and it rode well enough, I'd ride it just to hear the comments from other riders that get mesmerized by it when they follow.

Might be those chroniton particles getting out of phase. <grin>

Ya, that's a defective tire :eek:. I had one that looked similar. I had in my spare parts storage area for a while and had no idea if I had kept the sales receipt, so I couldn't return it. I ended up pitching it as it didn't roll well and I didn't want to risk a blowout while riding.

I had something similar happen on a cheap Cheng Shin 27x1-1/4. Upon looking inside the tire, I could see the threads coming apart.

I buy cheap tires on sale. Only had One Bad one.

You’ve got broken cords in the material that makes up the casing. The casing is just a fabric that has 40 to 250 threads per inch. I’ve had this happen before and, after cutting it apart, I found a couple of broken threads. The distortion is greater on the 40 to 60 TPI tires than on the high thread count tires.

Thanks for the replies, it's a 27x 1 1/4 tire, sounds like it's time for a new one. It's a cheap tire I bought off Amazon last year to get my old Centurian back on the road, two tires, two tubes, and two rim strips for $47. I had just taken it off one rim and put it on a new rim I had bought, I wonder if I could have done some harm with the tire levers, they are bike levers, plastic.

I don’t think it has anything to do with installation. Mine...I’ve only had it happen once...was spontaneous. It just happens.

That tire is damaged for sure. Replace it.

Underneath the rubber there are wires that hold the tire together, and, in this case some of them are broken.

If you don't replace it, it'll probably end up blowing up.

It looks like a Kenda K40 27" tire. These don't have great reviews, but I've had a set or two before and had decent luck with them. They are definitely comfortable tires, what with the relatively thick tread down the center section. I'd probably roll a die with another tire and see how it works out.

THe one piece of evidence that tells you your tire is damaged and needs replacing is if the tire has wobbles or bulges when inflated. THis is a sign that the casing under th tread is somehow damaged - possibly from a cut, or maybe a couple cords got old and were brittle. Either way, that tire is done. Replace ASAP.

There aren’t wires under the rubber. It just cotton or nylon thread. Some tires have wire beads but that almost never breaks and it wouldn’t result in the S-shape that royphotog is seeing.

Even at my level of cheapness that is toss and replace.

That can be repaired successfully - with sailcloth and contractor's contact cement. Real Dacron sailcloth as used for small sailboats (ask a sailmaker for a scrap) not the Joann's Fabrics "sailcloth". The glue to laminate countertops and the like.

I go this route to revive high quality tires (Vittoria Corsas and the like) with cuts to the cord. I've ridden tours on 3/4" cuts with that repair, no issues at all. Just retired a tire with no thread left that I repaired as a new tire several years ago. Sailcolth was nearly like new except it was not the cord that was showing through the tread!.

Not saying that is worthwhile here. Just pointing out this cord failure could be repaired,

I am always amazed at the "Is it safe?" posts.

Change it.

No matter the brand, any tire is cheaper than sutures, casts, slings, crutches, and ER charges. Even a simple fall with no serious damage can make you hurt for several days.

You are correct, it is a Kenda 27" and it was a comfortable tire to ride.

Tire replaced, and here is a look at the inside of the tire and the threads that are torn.
https://cimg0.ibsrv.net/gimg/bikefor...0022ab89a0.jpg

Pretty much the way mine looked. I’m not sure how it happens but it does. 40 TPI tire, by the way.

That would be threads per inch? Is that average?

Yes. Threads per inch. On the second question, are you asking if that’s 40 TPI average for the tire or if that is an “average” tire? If it’s the former, yes, it’s 40 TPI on average. If it’s the latter, a 40 TPI is an inexpensive tire. I’d say that an “average” tire starts at 60 TPI. A 40 TPI tire rides kind of harsh but is cheap to make and buy. More threads make for a more supple ride.

Thank you for posting a follow-up on this. We sometimes see a picture of the problem, several suggestions, and then radio silence. It's nice to have photos of the problem and the direct cause right in the same thread.

I've had that happen on a few tires. I call it The Dreaded S-bulge. One time it happened at mile 80 of a century. I made it to the finish and the tread was starting to wear badly - could have blown at any time!

It was to tires in general. In looking at tires for sale I don't see that spec in the descriptions.

I am guilty of that also, but I have been trying to get better at the follow-up. some people take a lot of time to reply to threads and I figure they should get at least a thank you and in this case there was a visual to show and for me to learn from. And you reminded me to reply to another thread about rims that I ended up buying.

I liked riding 27" tires on road bikes. I even miss them. However they went by the wayside before the turn of the Century and 700C's are the favored now for road bikes.

As a result you see all the new tire tech and high quality tires only marketed as 700C's or what ever the normal size is for other types of bikes sold today.

So you might think about that some. I got rid of my favorite ride 10 years ago because the choice of 27" road tires was so limited.

TPI is generally not given on less expensive tires. But even when it is given, it's not always so useful. For example:

https://www.continental-tires.com/bi...rand-prix-5000

Continental list the GP5000 has "3/330" for TPI. They're saying that there are three layers of fabric with a "total" TPI of 330. But that means that each layer is 110 TPI...and they've just layered three together. The math doesn't work that way. In other words, a tire with 5 layers of 20 TPI fabric is not "supple" like a tire with 2 layers of 50 TPI fabric, or some other combination of higher TPI count casing layers. Schwalbe's website states they list the EPI (Ends Per Inch, but same thing) for a single layer of fabric, even if multiple layers are used. So Schwalbe would list the GP5000 as "110" TPI.

Unless you know exactly how TPI is measured, the marketed or claimed number may not be useful (or even misleading). I would say the Kenda tire is probably in the 20 TPI range. You could probably measure it yourself -- take that tire that you removed, cut it open, and lay a ruler on the inside, perpendicular to the threads. How many are there in an inch? It looks pretty coarse -- as in, large threads with a relatively low TPI count.

I was seeing that as I got back into cycling last year, 27" was a thing of the past, and it makes sense that nothing new is coming out for them. My plan is to repaint the 1979 Centurian that I have now and ride it, along with the mid-90s Rocky Mountain Sherpa that I bought off Craigslist in August, till next summer, If I am still riding a lot I will look at something new in the road bike world. I can see that a lot of improvements have taken place and I am sure I will enjoy something new more.

The S-bulge isn’t an indicator of a blow out. If you look at rogerphotog’s picture, you can see that there are still cords holding the tire together. There is more than one ply of fabric in the tire. For the tire to blow out at the bulge, it would need to break more plies and the rubber of the tread. That’s a lot to break through. The tire will wear faster because of the increased squirm but it won’t necessarily blow out.