Product Review: Slime Tire Sealant

Can Slime out-perform the competition?


Image courtesy of Amazon

There is nothing worse than a flat tire, or a leaking tire. For years, Fix-A-Flat for bicycle tubes has been the go-to for riders looking to seal up problem tires. But there are some flats that Fix-A-Flat just can't handle. Which is why Slime, that green, aptly-named tire sealant you probably hear so much about, was created. And while there are a number of ways to avoid flat tires, if you ride with any regularity, you will eventually get a flat. That's why avid cyclists swear by Slime's ability to instantly fix flats as they happen.

Slime vs. the Can

The differences between Slime and Fix-a-Flat point to the different abilities that each of these very usable products has. For example, Fix-a-Flat is a liquid that is injected simultaneously with its own supply of compressed air. Some people don't like using aerosol tire inflation products like this because they think the end result can be dangerous. While this hasn't been proven at all, the believers are out there, and nothing will make them use that can. Slime works differently in that the sealant (that green slimy stuff) is injected into the tire before the process of reinflation starts. After you inject the Slime into the tire tube through the normal tire fill valve, you use your air pump to fill the tire up to correct operating pressure and hit the road.


Unlike Fix-a-Flat, which is meant to get you back on the road until you can change your tube, Slime is a semi-permanent fix. Once back on the road, the spinning action of your tires causes the slime to move throughout the tube, coasting every inch of surface and sealing all the leaks. The slime continues to do this as punctures occur, saving you not only time off the road but also money that you would have normally spent on new tubes.

And it seems to be non-toxic stuff to boot. According to their website, Slime relies on a "state-of-the-art blend of environmentally friendly fibers, binders, polymers and proprietary congealing agents which intertwine and clot within the puncture."


Unlike Fix-A-Flat, which is propellant-based, you have to squeeze Slime into the tube yourself after first removing the valve stem (Slime provides a tool with which to do so). Then you attach the can to a rubber hose, insert the hose into the stem hole and squeeze, while every so often rotating the tire to make sure you are getting even distribution. Once finished, you replace the valve into the stem, reinflate the tire, and off you go. While this all sounds simple, it can be time-consuming and even difficult, depending on the type of stem valve in your tire. And it can certainly be messy. Furthermore, some riders report that even though the Slime is supposed to be distributed evenly throughout the tire, very often it creates an imbalance that can affect performance. Which could mean you're just going to have to change your tube once you're home anyway.

The Work Around

If you don't want to carry around a can of Slime on every ride, much less hassle with the potential difficulty and mess, there is another way you can benefit from what is otherwise a great product: Buy pre-Slimed tubes. These are available at just about every bicycle store, and the manufacturer guarantees you'll get up to two years of flat-free riding out of each tube.