Slime Pro Tubless Tire Sealant. MSRP $18 for 16oz (473 ml).

Slime Pro Tubless Tire Sealant. MSRP $18 for 16oz (473 ml).

by Dr. Clifford Lee

Slime has been around for a long time and has products for every category of tire or tube whether it’s on an auto, lawnmower or bike. Tire sealants work analogously to our blood clotting system, though in a much more rudimentary fashion. When a puncture occurs, particles suspended in a solution aggregate at the hemorrhage to form a clot, stemming the further flow of solution and air.

Slime Pro is a new product formulated especially for tubeless systems. Gone is the slimy dark green liquid that looked like antifreeze, replaced by a milky lime green suspension that looks like a mint julep and smells tropical, like a piňa colada. It’s a latex-based suspension that slime formulated after testing their competition and consulting with racing professionals. A touted advantage to Slime Pro over other tubeless sealants is the anti-corrosion additives, though I have to say with anodized rims, I wasn’t really too worried about corrosion, but it’ll keep your brass valve stem from corroding.

I used Slime Pro in lieu of my typical sealant selection. The recommended use volume for a given tire size is equal to Stan’s, and certainly the smell is decidedly more pleasant. It actually improved the smell of my whole workshop.  Imagine saying that about a tire sealant! Funny that the advertising claims 1 gram per milliliter; EVERY aqueous (water based) solution is 1 gram per milliliter by definition.  Now add some particles in suspension and I suppose you could increase the weight per ml, but the amount of particles is not enough to affect this in any case.

The Slime Pro worked as advertised, sealing up tubeless conversions in several tubeless set-ups I tried with different rims and tires. I only had one goat-head puncture, and it sealed that up in about the same amount of time as another sealant I’ve used. The air loss was enough to make the tire squirmy, but I was able to pump it back up to the 25 psi I started with and no further leakage occurred. I continued to ride that tire without incident. I have not tried it with a road tubeless tire yet, but will. Containing the very high pressures of road tires after a puncture is challenging for a sealant. I’ve not been very successful in the past, having to ride home at 40 psi, or having to stop and put in a tube.

Slime Pro comes in a nice translucent bottle so you can see how much you have, and there is a pour nozzle with injection tubes, a measuring cup and a cap that has a Schrader valve core extractor on it. I can’t tell you it worked any better or worse than other effective sealants (Stan’s, for example), but it certainly smells better and looks more delicious!  Having the anti-corrosion components in the solution is an added benefit. I would definitely recommend Slime Pro tubeless sealant for cyclocross tubeless setups.

How to install Slime Pro Tubeless Sealant: