6

I find that any hole, cut or tear larger than a pinprick is impossible to repair with normal patches because they are too soft. Even a 2-3mm slit will cause the repair patch to balloon out and burst at that point. Is there a way around this?

  • 4
    Are you inflating the tube inside or outside of tire? – mattnz Dec 24 '12 at 3:16
  • You could also try throwing a dollar in between the tube and the tire - it may give you enough support to get you home. – lawndartcatcher Jan 2 '13 at 14:27
  • 1
    To clarify advice from @lawndartcatcher , put a dollar BILL between the inner tube and tire, i.e. paper money. Do not put a Canadian Loonie or other dollar COIN in there. Paper money is a common old school emergency tire "boot", the latter term not to be confused with parking boots used to lock car wheels in place. See Park Tool "TB-2 Emergency Tire Boot" - basically you can use a a piece of paper money to improvise one of those. – SSilk Sep 27 at 19:16
7

I don't think that you will have a problem with the patch ballooning out as long as the tube is inflated while fully mounted with rim and tire. To my experience there just won't be any room to balloon to.

If you fear that this will be a safety risk, I would recommend a new inner tube when the old one has such a big hole. When you are on a ride and have no spare tube at hand, even with a 2-3 mm slit a standard patch should be enough to get you home.

  • 2
    Patch cement also needs time to cure, so carrying a spare tube is a great solution and well worth the weight (better than carrying your bike home.) – WTHarper Dec 23 '12 at 21:57
  • I always carry a spare tube, but i also always repair tubes and use them as long as possible . What i am looking for is a way of doing repairs which are a bit heavier duty than a repair patch. Are there thicker patches out there? is there a way of making patches out of old inner tube? – rsk Dec 23 '12 at 23:57
  • 3
    You shouldn't have a problem with normal Rema patches covering a 3-mm cut. This sounds like an error applying the patch. The thickness of the patch isn't an issue (patches are already thicker and tougher than innertubes). – Adam Rice Dec 29 '12 at 1:26
5

Two points:

1) Tubes are pretty cheap. Better to replace one with a large hole rather than attempt to patch it. (Though 2-3mm cut should be easily repairable with a standard quality patch.)

2) If you have trouble with the tube "ballooning out" then it's not being properly supported by the tire. You must have a cut in the tire that (if it doesn't render the tire damaged beyond repair) requires a durable "boot". A tube is intended to be completely supported/contained by the tire and should not "balloon out" even if infinitely thin and pliable.

5

First of all: do not bother trying to patch too big holes. If it is just too big, just trash the tube. It is cheap enough and it's better than struggling and trying 10 patchings, wasting a whole patch kit all just to end up with it leaking and having a flat tire in the middle of nowhere.

Now, I have already successfully patched a hole as big as 5 mm. It was that big that the tube could not even be inflated to find the leak, it was not a leak, it was just an opening...

For that I used of of the bigger patches that are included in most kits. That worked just fine.

Apart from that I learned that my biggest mistake of patching over time was not to let the cement dry long enough. 5 or 7 minutes seems about fine before applying the patch. And do not hesitate to put it on a large surface to make 100% sure 100% of the patch surface is on a treated surface. This is actually easy to overlook especially on narrower tubes (such as those for 23mm and less tyres). And when applying the patch, make sure to press it hard on the tube, and especially the edges: these are the critical parts that you want the most to stick to the tube since they will be the first to "suffer" when facing an inflation, and if an edge loses adherence, it is the whole patch that is compromised.

I also had the feeling that the "feather" edges attach better handle better the expansion when inflated than the straight edges.

  • 1
    When I apply a patch I generally use a tire iron or the corner of the patch kit box to rub down the patch and make sure it's fully adhered. – Daniel R Hicks Jan 2 '13 at 16:38
2

Nobody's said it explicitly, so I will: ordinary patches are completely fine for slits and holes a couple of millimetres across.

Your description of the patches "ballooning" suggests one of two things. Either you're inflating the tube to moderately high pressure outside the tyre, or there's a significant hole in the tyre that the tube is coming through. In the first case, the fix is "Well don't do that, then". Once the patch glue has dried, you can inflate the tube until it just starts to expand, to check that there aren't any other holes, but you don't need to go any farther than that. In the second case, you need to repair the tyre, too.

Having said that, I'm a bit confused by anything ballooning at all. Patches are usually less stretchy than the tube itself so, when you pump up a patched tube outside a tyre, it's usually narrower at the patched area, not wider.

-5

Have you try using roofing patch? Try cut a giant patch from old tube.

  • 1
    Also, your answer isn't clear. You seem to be saying use a roof patch, and cut a section of old inner tube out as a patch. Those are two different things. Are you sure a roof patch would work, i.e. would it glue successfully to a butyl tube? – Weiwen Ng Sep 25 at 23:03
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    I have used a large piece of tube scrounged from another dead tube, and it worked surprisingly well though took a lot of vulcanising fluid. Could you used edit to enlarge your answer? Needs to be more detailed. And I have no idea what a roofing patch is in this context - could you explain that further please ? This could be a good relevant answer. – Criggie Sep 27 at 3:13
  • I feel this could be a good answer if someone took the time to write it out in detail with photos. Any volunteers? – Criggie Oct 5 at 2:49

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