I only recently ( jamuary) started riding again after many many years, and am commuting. So I thought, hey I will slime the tires to make it so I don't get flats. I now regret that decision.
so I slimed my tubes, and it is a hassle, even though I keep the valve up high when checking ( between 11 and 1 on a clock), , at times, it squirts out on me, or my gauge or my air chuck or the side of the rim.

But yesterday, b4 riding off to town, I went to check the air pressure. Got the squirt,
But worse than that, it kind of made the valve core stick and it let out a bunch of air. only after hitting a couple of times with my gauge did it finally seal. with all the extra air coming out, so did slime and made a mess
luckily I was at home with my compressor
but now Im gonna be reluctant to check my tires away from the house.

I guess I know my next bicycle part purchase. new tubes that wont get slimed.
was gonna phase em out anyway, because of the mess they would make if I ever got a flat that the slime did not seal, and I was on the side of the road trying to install a spare tube with the mess. Running thorn resistant tubes and Kevlar or the like tires, I should be ok anyway

so if your thinking of adding slime, and doing a search and come across this thread, its just another thing to keep in your mind when making your decision.

I was airing up a tire on a bike that had Slimed tubes unbeknownst to me.
Blew enough Slime into the pump head that it never was able to reach it's max pressure again.
It was a CHEAP (<$10) floor pump, but was good to 50-60 PSI. Now it might hit 30-40.

I've never had Slime actually do any good. Even small holes caused by pieces of wire wouldn't seal. I had multiple punctures when I was running Slime, all went just as flat as without it.

The only thing Slime does is to spray all over everything and make a mess, requiring a lot of cleanup especially if you want to patch the tube.

Yeah, I tried that stuff and gave up on it. It gums up the valves so it's hard to put air in. It seals up minor punctures, which is fine, but often you don't even know they happened; so little by little the sealant goes away. You will have no warning that the sealant is almost all gone; but the day comes when you can't keep air in the tire any more, and you're probably not prepared.

Worst of all, I've never been able to get a patch to stick over a puncture if there's slime in the tube.

Slime hardens up to stop air from coming out of your innertube, including from the valve, which is a problem.

If it makes any of you feel better, I also learned the hard way that Slime is more trouble than it's worth, for the most of the same reasons given above. What's more, while mounted on a bike parked in my hotel room, one of my slimed tubes extruded itself at full pressure between the tire and rim, at the bottom of the wheel of course. Helluva mess is putting it mildly.

I put some new 1.5" slicks on my mountain bike commuter about 7 weeks ago, the tires I bought don't have any extra flat protection and my commute has a lot of glass and debris. I was having a heck of time with flats, getting at least 1 or 2 every week. About a week and a half ago I installed some some rhinodillo tire liners. So far, no flats with those. Obviously a week and half is not an adequate test period, but as soon as I installed them my confidence went up, they just seemed like they would work. The tubes are holding air like champs now. Reading reviews I notice many people say tire liners cause flats by the ends of them digging into the tube, I covered the ends with tape which seems like it might help (could find out later that I'm wrong) and I made sure to to take the time to seat the liner correctly in the tire. Also any difference in rolling resistance must be negligible as I haven't been able to decide whether I can even tell a difference or not. After these tires wear out I'll probably try running some puncture resistant tires without the liners and see how it goes, but the way things are going I won't hesitate to stick some liners in if I find myself patching tubes. Now the tire liners better do well by me after this good review I'm giving them on here!!

I've been using self sealing tubes about a year now. They've held up better than basic ones, and just as well as thicker tubes.

One thing I've noticed though is that they appear to lose air slower via natural osmosis than regular tubes.

M.

I agree, that stuff is worse than useless. If you're worried about flats, use tires with kevlar liners. I ride in NYC and I only get a couple flats a year at most on my Panaracer Pasela Tourguards.

I've had it get me where I was going without much delay a couple of times. It's caused problems once or twice with my valve stems. I still run it on my commuters, but decided not to run it on any long distance bike.