Take the 2-minute tour ×
Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. It's 100% free, no registration required.

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?

share|improve this question
1  
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

3 Answers 3

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.

share|improve this answer
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

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.

share|improve this answer

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 security 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 new tube at hand, even with a 2-3 mm slit a standard patch should be enough to get you home.

share|improve this answer
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
1  
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

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.