I ran over some glass on a ride last weekend early into my ride and the glass cut through the tire and tube. I replaced the inner tube on the spot. The glass left a small gash in the tire but I didn't think much of it. I completed the ride, which was about a 25 mile loop. I got the flat about 2 miles in, so I rode about 23 miles with no problems.

I inspected the tire and there is a small hole maybe 2 mm or so in diameter. I decided to patch the inside of the tire as a precaution. Do you think it's safe to ride with? Obviously, I completed one ride with no problems. The patched tire is on the rear. I've ridden several tires in the past with holes worse than this one with no problems, but I'm wondering if there is a general rule of thumb about whether one can or cannot continue to use a tire based upon size of the puncture.

For reference, this is an espoir sport 25mm tire.

For cuts on tubed tires, the relevant question is whether the tire's casing fabric can still contain the air pressure within. If the fabric has been cut and the area around the slash is bulging when the tire is pumped, then it needs replacement.

Each person makes their own conclusions on what is OK or not.

Tube poking out, or swelling of the casing would be a definite NO, everything else lies in a grey area.

One risk is that certain types of grit may get in and tend to chew through your patch if the hole is large enough.

Many people choose to put any "questionable" tires on the rear to wear them down quicker, and to reduce the likelihood of dangerous issues on the front.

I agree with the "if the tire isn't swelling in the area of the hole, it is probably OK." I also put a bit of Shoe Goo in the outside of the hole to keep anything from getting in there from the road (I do that after rides, not during, and for slits that didn't result in flats, too) Looking at the holes/slits is a good way to tell how worn the tire is and these days I err on replacing early vs. fixing flats on the side of the road.

Fixing flats is a pain... especially if one is on a tight schedule.

On the other hand, with today's "armored" tires, I'm not convinced that simply wearing the rubber thin increases risk of flatting. My theory is that most of the protection comes from the tire casing, and thin rubber has less likelihood of picking up debris.

That is, of course, dependent on the casing being mostly intact.

I haven't been filling holes, although I have a large hole in one tire that I have't decided what to do with (other than not ride the tire). I did fill holes in another tire with super glue once... it seemed to work, but the next time I inspected the tire, I had difficulty discerning super glue from debris, and picked several of them out. In the end, I wasn't convinced filling helped.

I'll take the bike for a spin this weekend. There's no bulging and debris can't get through since there's a tube patch on the inside. I've ridden for long periods of time with larger cuts and never thought much of it.

Unless you patch the tire with a patch that has real strength. I've patched many tires with dacron sailcloth (not the"sailcloth" you can get at fabric stores, the real stuff; scraps from a sailmaker). I cut the patch oversized then glue it in with contractor's contact cement (with its toxic fumes; the stuff for countertops). I've put a thousandmiles on cuts nearing an inch. The tires died from natural causes.

Ben

Next time I get to Portland, remind me to head up to the islands to the north...

Or, perhaps you could bring a few feet to [MENTION=381793]gugie[/MENTION] to distribute.

My theory is if the threads are cut, and you can see they are cut & seperating, then replace the tire.

I run Mr. Tuffy liners now and am not so worried about tire condition, but I still inspect regularly. As a commuter, I don't want to risk a tardy attendance on account of a shard of glass or a staple.

One time, I got a slice in a racing tire. I got a flat right through the liner and everything. I pulled out the offending object, patched the tube, and rode the last 80 miles of the century with the casing split & the liner plainly visible. There was a flap of tire coming loose near the end & I could feel it with every revolution, but the liner held everything together.

If you are concerned, Mr. Tuffy or the competing brand Stop Flat (No Flat?) is great piece of mind. Buying 1 size larger than the package says has been a good idea in my experience.

Patching is ok, but to be sure, I like to put a smaller tire underneath the cut one.

You are probably right - I have noticed that in the past 10 years I have gotten many fewer flats/mile than years ago. I'm buying better tires, checking them after each ride and running lower pressure/wider tires than I used to - all of that contributes, but the tires are definitely more armored.

I've tried rhinodillos. The ride is more sluggish. They definitely slow you down. Fewer flats for sure, but they don't prevent flats altogether as glass and goatheads can cause punctures just outside the liner.

I put a piece of an old similar tyre (without the beads) inside the damaged part and that containts the pressure just great.

It's a budge, more weight, you lose the wheel balance and wouldn't do it with a light or latex tube, but I hate to bin an almost new tyre and it works.

There are lot of YouTube videos on the subject. I needed them once or twice.

I've never tried Rhinodillos. I have heard that the ride with liners is sluggish though. I don't know if the amount of time spent fixing flats is more or less than the delay caused by the supposed added rolling resistance or not. TBH though, what I would like even more to have is a surface to cycle on that I would be able to actually tell the difference one way or the other. Even better would be a surface that I wouldn't need to worry about the need for flat protection! I can't say I could/can tell the difference in a blind A/B test, so many other things to consider that just aren't worth the time for a general purpose fitness cyclist.


As far as goatheads/glass/etc...I think using one size wider is smart. That extra nth of protection certainly isn't any more costly than already accounted for by the decision to have them in the first place... For a long time, I ran ultra light tubes because I figured that if it managed to get both through the Gatorskin Hardshell & the liner, then no amount of tube would've made a difference. The ultra-light liner + the ultra light tube came out to the exact weight of a regular tube right down to the gram. So why not have the extra protection and sidewall compliance offered by a light tube? I've long since lost track of which wheel/bike has what. The road surface and proper inflation pressure, I think, are the most important determining factors.