The slime should stay in the tube! One thing to note; when you air up the tire with the slime tube, make sure the valve is at the bottom of the tire. Keeps gravity from allowing the slime to leak out of the valve. I only use a slime tube on my mtb bike, and only on the rear tire. It must work - I've never gotten a flat on that tire.

I don't use slime tubes on my lightweight road bike....... I don't get flats that often and I honestly don't want to add the extra weight. Not just weight but rotating weight that you are pushing around with every pedal stroke. I got that bike to ride fast and adding unnecassary weight doesn't make sense to me. Different story on my touring bike. Considering what it weighs to begin with, adding extra weight wouldn't even be noticeable. If I got a lot of flats, I'd go with a slime tube, at least on the rear. Taking bags off to change the tire is a pain! So far, tho', it hasn't been an issue and normal tubes are fine.

It's definitely a matter of individual preference. If you hate changing tires and get lots of flats, go for the slime. If you are trying to keep the bike lightweight, don't get many flats, and are comfortable changing them, then skip the slime.

annie