Patch or Replace a Tire?

[Matthew Williams]

As I was riding this evening, I saw shards of broken glass glittering in the beam of my headlight but I wasn’t able to swerve out of the way. I heard a small pop as my front wheel ran over the glass, then a loud hiss-isss-isss-isss as the tube deflated and I rolled to a stop.

“No problem,” I thought. “I’m only a block from home, and I can test the patch kit I’ve been carrying.” At home, I removed the wheel and unmounted the tire. The hole in the tube was about seven millimeters wide and I’d already patched the tube twice, so I installed a new tube—but when I remounted it and pumped up the tire, I saw the new tube was poking through the hole in the tire! 

On a car, a tire shop could simply install a patch on the inside of the tire, but I’m wondering if the damage to the tire is too extensive to repair. The tires (Panaracer Gravelking SKs) are nearly new and have fewer than 100 miles on them—they still have the little “new tire hairs” and that white waxy stuff.

What’s the wisdom on this sort of tire damage? Can the tire be patched—and if so, how? Or, do I need a new tire?

As always, your wisdom, advice, and experience are greatly appreciated.

[Luke Hendrickson]

I’d (unfortunately) suggest replacement in this case. 

[Jeffrey Arita]

Matthew,

You could try patching the tire.  I've used Rema's TT13 Tubeless Repair Kit (sorry, can't post hyperlink as we're away from home).

We were on a bike packing trip in the middle of nowhere when my wife sliced her sidewall on a sharp square rock.  Sealant wouldn't repair the long cut - as expected.  Ended up removing the tire, emptying the remaining sealant (yes, messy), cleaning the area of the sidewall cut, applying the patch AND installing a tube.  The tube ended up actually helping to meld the patch to the inside of the tire since it was compressing the two together.  Obviously the patch prevented the tube from bulging to the outside.

Might be worth a try since that SK is practically brand new.

Also: since you may have run over other bits of glass I would suggest you inspect both tires: tiny shards may have embedded themselves into the tires.  They could slowly work themselves thru the tread, eventually puncturing the tube(s).  One way to check is to chuck each wheel into a wheel stand, deflate the tire completely then pinch the tire and carefully examine the entire circumference. I typically start at the valve stem and go all the way around.  Have a pick or small tweezers handy to pick out any of the shards or other debris embedded.  A powerful headlamp helps too.

Good luck,

Jeff

[Garth]

Hmm, Myself I'd grab an old worn tire if I had one on hand, and make a small boot for underneath it. Inflate it and see how the cut now appears, if it's gaping more/less and such. I've never had a boot that didn't work or fail, those were all on narrow high pressure road tires. A knobby at much lower pressure should be a breeze. 

[Nick Payne]

That cut looks a bit large. You could try a tyre boot cut from an old slick tyre to see if the casing continues to herniate with the boot inside it. Or you could try a tubeless repair kit. I've used the Hutchinson Rep'Air kit on both tubeless and tubed punctures, but the cuts I fixed were not quite that large. I think the instructions with the Hutchinson claim it can be used on punctures up to 5mm size.

Nick Payne

[John Rinker]

Because the slice is below the knobs, I'd try sewing it up with a stout nylon thread, covering the thread with a wipe of Shoegoo (inside and out) and a tri-folded Clifbar wrapper (tough material) on the inside between the tube and tire. This has worked well for me when living in countries where tires were hard to come by.

Cheers, John

[John S]

I have had good luck covering smallish cuts with Gorilla Tape on the inside of the tire.

I was able to successfully repair a tire with a larger slice in it using a very inexpensive radial tire patch kit (I used this one: https://www.acehardware.com/departments/automotive-rv-and-marine/tire-maintenance/tire-repair-products/8023916). I was even able to continue running that tire tubeless.

[Rick Harries]

And if you decide to repair it in some way, consider moving it to the rear wheel. Less drama if it fails in the future. 

Rick Harries

Easton, Maryland