Originally Posted by Fabula
Not used them, but a friend who is a bike nut warned me off them as they tend to dry up and stop working after 6months to a year, so need replacing regularly. Given the cost differential, they are apparently not worth it.
I definitely think they are worth it. I have some on my mountain bike, and I rode for nearly 2 years (3-4 hours every Saturday) without being inconvenienced by a puncture. I still got a few, but they either healed, or went down so slowly I did not have to fix it till the ride was over. There was no sign of the slime drying up when I eventually got a puncture from a huge nail.
A bike shop I used to go to had a demo of slime, that consisted of a small wheel from a child's bike, and a board with a nail in it. They would puncture the tire with the nail, and it would heal in a few seconds as you watched. I dare say there was quite a bit more slime than normal in that tire, but it was still very impressive.