[zandr]

Five miles from home on this morning's ride I started hearing a thump when once per wheel revolution. Turns out a pretty sizable bubble had developed in my rear tire and was hitting the caliper. I lowered the pressure in the tire and managed to make it home.

I know there is a pinhole in the tire from a small piece of wire I removed two weeks ago. I'm assuming this is where the bubble developed. I did use a patch kit on the tire but obviously it didn't work very well.

Questions:
- I am assuming this tire is no longer safe to ride. Is that correct?
- Is there a simple way to fix this?

A replacement tire won't cost all that much so I'm not going to mess with a long, complicated fix. However I'd rather not buy a new tire if it is repairable easily.

 

[11.4]

Not safe to ride and not really repairable. If it's hitting the calipers, it has to be a pretty decent sized bubble. Your flat was likely not the source of this one unless at the same time you hit something bigger. A bubble most often results from a separation of the plies from a nasty hit by a rock or other road hazard. Occasionally it can be a cut, but if a cut then you should see it clearly on the outside. If it's just a bubble showing up under the rubber, your plies separated. Sometimes it can be a manufacturer's defect, so it's worth showing it to a shop but don't expect much.

 

[zandr]

Thanks for the response. That's basically what I expected (not repairable, not safe to ride). I didn't realize it was likely from a rock hit or something but now that you've mentioned it, I didn't see the hole I patched on the bubble. I'm sure it's one of the (many) rocks/etc I rode over this morning (shoulder of a highway). The tire has ~1,850 miles on it so the manufacturer defect angle is probably not going to work with the LBS.

Thanks for the help!

 

[Kerry Irons]

Boot it and see

Five miles from home on this morning's ride I started hearing a thump when once per wheel revolution. Turns out a pretty sizable bubble had developed in my rear tire and was hitting the caliper. I lowered the pressure in the tire and managed to make it home.

I know there is a pinhole in the tire from a small piece of wire I removed two weeks ago. I'm assuming this is where the bubble developed. I did use a patch kit on the tire but obviously it didn't work very well.

Questions:
- I am assuming this tire is no longer safe to ride. Is that correct?
- Is there a simple way to fix this?

A replacement tire won't cost all that much so I'm not going to mess with a long, complicated fix. However I'd rather not buy a new tire if it is repairable easily.

You may be able to boot this tire and get many more miles out of it. One very effective and low cost boot is a double, triple, or quadruple folded piece of Tyvek (the white "synthetic paper from a FedEx envelope). Before booting the tire, you should do an inspection to see if there are broken casing threads under the bulge. If yes, then the boot is likely not going to work but it depends on a lot of details. Long story short, if you put in the boot, pump up the tire, and there is no bulge (or only a small one) then you are good to go.

As others have noted, you're most likely not seeing a "bubble" like you would see on a car tire but rather the inner tube starting to extrude through the damaged casing. Odds are, the tire is toast, but you can try a Tyvek boot virtually for free, so it's worth a go if you're cheap like me.