"Quick Fix" Tyre Repair Spray Cans
Pro's:


May be a quick roadside fix.
May be able to fix without removing tyre.
May last a long time.
May offer protection against a second puncture in the same wheel.


Con's:


Expensive for a puncture.

Bulky and heavy.
Only one can per tyre.
Wouldn't be suitable for some punctures and would be a waste if you didn't realise this.



This fix may work for a long time, dependent on the sealant and whether it degrades. Silicon sealants do not degrade quickly.

This type of system is good for small punctures where you can quickly identify the cause and eliminate it. If you have a large puncture (such as a tear or a cut) the sealant may not be able to effectively seal it and once the air leaks you would not be able to re-inflate it.

Also it's best practice to ensure you remove the cause of the puncture before inflating a flat tyre. This generally involves removing the tube and checking the tyre so you're not actually saving that much.. If you don't do this you may get a subsequent puncture.

If you are that adverse to fixing a tyre in the rain or at night use a preventative treatment rather than a temporary repair such as this. Use slime tubes (or fill tubes with slime) or move to tubeless and use a sealant such as Stan's. I ride single track twice a week and have put a single scoop of Stan's in each tubeless wheel 6 months ago and have yet had to remove the tyre. I occasionally add air (probably a month ago and this week) so I know I have a leak somewhere but it hasn't required me to fix it yet.