Slime Tube Sealant Review

Slime tube sealant

Photo from Amazon

In concept, Slime Tube Sealant makes sense. Fewer flat tires—always a good thing, right? Though there are ways to reduce the number of flats that you get, some are inevitable, and Slime Tube Sealant is supposed to be that next layer of defense. Sure, it can help, but it has its downside too. The biggest problem with the Slime Tube Sealant in a bottle is that it is messy and surprisingly difficult to install.


  • Slime is guaranteed for 2 years. Remains liquid inside the tire, coating the tread area as the tire rotates.
  • Slime has a freeze point of -30 F (-34.4 C) and a boiling point of 220 F (104.4 C).
  • Non-toxic, non-hazardous, non-flammable, non-aerosol and water soluble.
  • Prevents and repairs punctures up to 1/8 inche (3mm) using Fibro-Seal™ technology.

Review of Slime Tube Sealant

Slime Tube Sealant is a great product, generally speaking. When your wheel spins, the liquid sealant spreads all through your tube, providing a constant layer of flat protection, in many cases fixing small punctures and blocking leaks that you don't even know you've had. When a puncture occurs, the sealant moves into the hole and clotting agents are activated, effectively filling the hole and blocking the loss of air. The concept is a good one, and it certainly works with the Slime tubes that have been on the market and a favorite of cyclists for years.

However, what we are reviewing here is the bottled product, the green goo sealant that you install yourself, and not the pre-treated Slime tubes that come with the sealant already in them that we looked at in another review.

While the tubes are great, my advice is to stay away from the bottled Slime that you take home and squirt into your existing bike tubes. This is because the installation of the sealant is difficult enough that it's not worth the trouble to even try. Basically you have to take your Schrader valve tube and unscrew and remove the small valve inside the stem using a tool built into the bottle cap. The next step is to squirt the sealant inside the tube using a provided rubber hose that connects the bottle to your tube stem, kind of like a drip IV bag. You then replace the valve into the stem, reinflate the tire and off you go. Maybe a four level difficulty on a scale of one to ten.

Where it gets really tough (seven difficulty on ten point scale) is in squirting Slime sealant inside presta-valve tubes, which have the long skinny stems like you find on higher pressure tires like many road bikes have. There you have to unscrew the itty-bitty nut on top of the valve, and let the thin and narrow valve drop into the tube but while still holding it with your fingers. You then infuse the tube with sealant, squeezing it from the bottle with the hose and then hopefully reversing the process without either losing the nut or dropping the valve down into the tube while you're squirting it full of goo, which would make your tube useless and render futile your whole effort. It's just not worth it.

In Conclusion

If you want flat protection, do yourself a favor and buy the Slime tubes that come pretreated with sealant and just go rolling with those. They're cheap and it's not nearly worth the hassle to try to go the other route, squirting the sealant from the bottle into your existing tubes.

Prices for Slime Tube Sealant

$8 to 10 for 16 oz. $30 for a gallon, which would typically be for commercial use, like a bike shop. 16 oz will be sufficient for just about every cyclist, with plenty left to share with friend.