What is the maximum number of pucture repairs an inner tube can take?

Question

Any thoughts - my spare tube that I carry in my bag currently has a dozen or so patches on it, but still works fine. I'm tempted to keep going to see how many I can get on there until it get impossible to mend.

What is the most number of patches you reckon a tube can take ?

(And I know new inner tubes are only £5 or so, but a puncture repair costs about 10p if you buy the patches and glue in bulk, so "It's cheaper to buy a new one" is not necessarily true...)

Answer 1

I would carry at least one unpatched, pristine tube as a spare. Put the patched ones on the bike or keep for repairs at home. The idea being that when you need it -- in the middle of nowhere, in the dark and pouring rain -- you're guaranteed that the old patches aren't peeling off or weakened and the tube should "just work". Then swap it for a patched tube when you get home if you like.

Answer 2

When the patches start to overlap, or you are fixing old patches that have failed, it is time to get a new tube.

Answer 3

I find the bigger problem is not the number of patches, but rather the age of the patches. There is a correlation though, in that by the time you have patched a tube for the third time, I find that the first patch is starting to get a little suspect.
In my student days I would patch a tube four or five times, but I often had patches eventually fail.
Nowadays I draw the line at two. Tubes are just too cheap to have one fail on you in the middle of a ride. The time and inconvenience of having to change a tube that has failed is not worth the money, especially since it always seems to happen on wet windy nights!