Cyclocross tyre patching problems, bulging inwards

Question

I bought a new cyclocross bike, very good very handsome. 2 days ago I rode it on quite a rough road composed only from rocks. Two punctures (slow leaking ones, cause only realised after coming home 2 hours later, tire was a little quite deflated).

I bought a patching kit. Patched as usual. I used to have a mountain bike, so I think I patched it well. But this time, with the CX tires, I ended up with two annoying (and very uncomfortable to ride) dented inwards tires. If you try to rotate the tire, you see a single dent on each of the tire. So ... I think it must be coming from where I patched it.

What are your thoughts on this?

My thoughts are:

1. If you patch a narrow tire, don't glue the whole patch to the tire, glue only a small part, touching a puncture. Couple of millimeters in diameter. Cause if you do, you might end up with the tire tightened at the place of patching, and when inflated, it will have smaller diameter.

2. Well, first described pretty much everything.

Should I buy a new tire? (I think I will anyway, this bulge is punching my bike like hell with every revolution.)

Should I be careful next time? How?

And just in general, suggestions for patching small tires.

Answer 1

If you inflated the tire and the tire itself is indented at times, it is likely that you did not seat the tire correctly. This means the tire bead is not sitting correctly in the rim. The rim should have hooks to catch the tire bead. The tube should expand to many times its original size and will fill the volume made available to it. As such, a tire that is not seated properly will present a different radius to fill making it look like the tire is indented.

Try deflating the tire so that is has a very low pressure then squeeze and pull on the tire to try and get it to seat properly. Re-inflate, then check.

Also sometimes a high pressure can make the tire seat correctly.

Finally, if your rim tape has slipped it can interfere with the tire seating correctly. Check to make sure the tape is in the proper location.

Answer 2

First thing I would suspect is that you somehow installed the tube incorrectly, maybe twisted.

Next, you may have installed the tube before the glue dried and failed to dust the patch with talc, causing it to stick to the inside of the tire.

Or the tube may have been too small from the start, and the patches are keeping it from stretching enough to fill out the tire.