When a self-sealing inner tire tube is punctured (up to 1/8), it is said to reseal itself. But does it reseal the puncture for good or does it just give me enough time to get to a place where I can change / patch the inner tube?Also, does using tire liners affect the tires in any way at all (aside from keeping me from having flat tires)? I have a mountain bike but I use it only on paved trails.
Self-Sealing inner tubes are only meant to go for a short period of time after a deep puncture. Not to say you should stop riding, however before you set out on your next slopes, you should get them changed. Have you rode your bike with tire liners.? I have never used them, however, I have heard some random complaints. try them out before you commit to them on a long ride.
I tend to use slime tyres on mine. They will self seal most small punctures (If you want better performance, try tubeless system). Once a month I will take the tyre off and pull out any thorns that have punctured the tyre. I will then repair and re-inflate. Once I have done about a douzen repairs, I will buy a new tube. Since you use a liner, this will perform the same function. I would therefore look at repairing your tube, like me, once per month. (Note: Slime has a life span. Replace after about 6 mths.) Luck
In my experience, sealing tires tend to be a little heavier then regular tires but they work for small thorns. If you happen to ride over a nail, they never seemed to work. I've found it a little harder to fill air into self-sealing tires as well. Tire liners are very easy to install if you have tire removal tools. They just slide between the tube and your tire. I have never had problems with them but I have used them with self-sealing tires(used to ride near star thistle patches and killed too many tires). Most tire liners only protect a small section though and if you get a spike through the side, it will still puncture the tube. One warning about a tire liner: be sure the liner is secure in place when you put it in before inflating the tire. If the liner is askew, it can pinch the tube and eventually punch a hole in it. Also, most tire liners will throw the balance of your tire off a little.