Slime tubes have this green goo inside them. When you get a puncture the goo fills in the hole. I have gotten one flat while using slime tubes. I knew I had hit something, but didn't get a flat while riding. I got home parked the bike, looked at it a couple of hours later and had a totally deflated tube. The goo filled the hole, but once I stopped moving the tire did eventually go flat. That's okay with me. Changing a tube in the comfort of my home is a lot easier than doing it on the road.

They are heavier than regular tubes. But I certainly don't notice the difference. I replaced the slime tube with a regular one as that was all I had.

V.