human909 wrote:
Why not? By being less wasteful is that not marginally better? (I won't ever claim to be personally 'saving the planet', but I do live a minimalist lifestyle.)
Yes marginally better for sure, but almost certainly swamped out by many other lifestyle factors, and possibly negated by as little as one or two trips in the car. That's why I prefer to base my reasoning mostly on cost and reliability.
If my patches are reliable enough so that the next "incident" is significantly more likely to be another unrelated puncture rather than a patch failure, then I'd call that a success and say keep on patching. The problem arises when the next failure is more likely to be a patch giving out than an unrelated puncture, and then it becomes a real reliability issue. Sadly I think that is what a lot of people are seeing these days.
The type of tubes I've had patching reliability issues with lately are high pressure narrow (18-25c) ones. I think it's a combination of the higher pressured but also the tighter radius that the patches have to curve around. Surprisingly I've also found lower reliability on patches that face inwards compared with patches that face outward and fully contact the tyre. With bigger tubes for lower pressure wider tyres however, no real problems and plenty of successful long term patches.
I also like to have a few known good patched tubes around as spares. When you suddenly find yourself down to your last new tube with nothing to carry as a spare, they are certainly better than nothing.
Rather than immediately re-use a patched tube, I find the best thing to do is to mount it on a spare wheel and just leave it fully inflated for a week or two. If it's still good then it's a spare, otherwise it's a dud.