Tag Archives: bike tire sealant

I first saw the Flat Stopper tire sealant at Interbike. The flat Stopper booth had a wheel affixed to a stand that had a jagged spike that would puncture the tire if you pressed a lever. Based on this display,

“The Flat Stopper” could be your future tire sealant!

By John Brown, HaveFunBiking.com

I first saw the this tire sealant at Interbike. “The Flat Stopper” booth had a tubeless wheel affixed to a stand that had a jagged spike that would puncture the tire if you pressed a lever. I have seen this type of fixture before and it always works just about the same. Puncture the tire, watch sealant squeak out, then in a few seconds it dries. What made the Flat Stopper different, there was no delay, no squeak, only an immediate tire repair. Based on this display, I needed to try this sealant myself.

Out of the box tire sealant

The Flat Stopper comes in a few different quantities. The most consumer friendly are the 3.5oz and 7oz flask. For shops, The Flat Stopper has just released a 3-litre box. The Solution is red in color and has a low enough viscosity where injecting it through the valve is easy. Surprisingly, I learned that the sealant is functional down to -20 degrees Fahrenheit and will not dry out like many latex based sealants. In other words, “The Flat Stopper” seems to be the product that could make tubeless perfect for the masses.

Flat Stopper in a 3.5oz package.

Into the tire

My first impression using this sealant in a tubelesss tire was how it seemed to be thicker than the latex solutions I had used in the past. Even though it has a consistency similar to gel, it flows surprisingly easily around the tire. When I aired up the tire I was surprised to see nothing happening! By that I mean, I didn’t see any sealant weeping out of the tire’s sidewall or where it meets the rim. This is a stark contrast to latex sealants who frequently leak out of a new tire until everything seals up.

Flatstopper sealant poured directly into a tire

What happens during a puncture

Where flat stopper overachieves is in how it seals. Most tire sealants work through a process of adhesion. As an example, an adhesive sealant is suspended in a liquid carrier. That carrier evaporates quickly is the sealant exposed to air (like in the case of a puncture) and the remaining latex adhesive seals the hole. The Flat Stopper works through a process of compaction. It has particles suspended in a liquid carrier. When the tire is punctured, the particles compact in the hole and seal it immediately. Considering the liquid doesn’t need to dry for The Flat Stopper to work, the sealant last longer in your tire.

How it works

I have to say, I am really impressed with this sealant. It was installed it on our Demo Marin B17 about 4 months ago. Additionally, I recently checked on that bike to find the tires are nearly completely full of air. This is amazing news considering it was hanging in my garage through our winter freeze. The sealant I installed in a test wheel seals any and all punctures I put (purposely) in the tire.


Considering the sealant has been holding well for the past four months, I am excited to see if it actually does ever dry out. If I don’t see any drying In the net few months, that will be impressive. Another thing I like about this sealant is the ecological responsibility the company has shown. The consumer packaging is small, recyclable and reusable. They also produce a large shop volume that is shipped dry, and mixed by the user. This lowers the carbon footprint in shipping and cuts down on unnecessary packaging.

Revolutionary products in this review include the Carlito bike lock and the Flat Stopper's amazing new tubeless bike tire sealant.

Revolutionary products the Carlito bike lock and Flat Stoppers tire sealant

By John Brown, HaveFunBiking.com

It’s been about two months since the Interbike show and there are a couple of new products I am excited to share. Each year I go to the show to find the most technologically impressive products there. This year was no exception and there were two new products that I have spoken with friends about that were created by inventors who looked at a certain problem in a new way. The first is the Rocky Mounts Carlito bicycle lock and the second is the Flat Stopper Tire Sealant kit. Read on for more details.

Rocky Mounts Carlito Bike Lock is one of two revolutionary products

Rocky Mounts is best known for their car racks, but recently they have moved into bike locks as well. Their line of bike locks covers all the basic options and introduces an all new concept. That Concept, is the Carlito lock. The bike lock looks like a standard mini U-lock but incorporates some really cool features. First, Rocky Mounts chose silicon for the cover material. Therefore, the Carlito lock is softer on paint while being more durable than a vinyl covered lock. More importantly, what makes the Carlito so cool is the material they use for the lock itself. Rather than using hardened steel for the construction, they employ aluminum alloy. While aluminum is not as durable as steel, it’s half the weight. So for anyone looking for the visual security of a U-lock at half the weight, the Carlito is an amazing option.

Carlito Lock

(left) Carlito lock and Key (top right) and U (bottom right) detail.

Flat Stopper tire sealant is also impressive

Tubeless tires are now a standard feature on every category of bike. Almost all tubeless systems use the same type of Latex based sealant to seal punctures and keep the tires airtight. Where The Flat Stopper differs is that it is not Latex based. In fact, rather than latex they use completely inert ingredients that contain no ozone depleting chemicals and aren’t carcinogenic or flammable. Moreover, it’s actually a water based system. While their exact recipe is a secret, I did get some inside info on how their sealant works. Apparently, rather than relying on latex to dry out and seal like most systems, Flat Stopper works through pressure. Therefore, once the sealant gets forced into a puncture (by the tire’s internal air pressure) it immediately seals the hole permanently.

Flat Stopper Sealant

Flat Stopper’s clean packaging (left) is perfect for quickly filling your tires with sealant. On the right is a close up of what Flat Stopper looks like up close.

Connecting Thread

The thing I like most about both these two products, they are a totally new approach to existing solutions and the problems they are suppose to solve. The Carlito bicycle lock offers moderate physical security as well as a high level of visual security all while weighing practically nothing, making this new approach to security exciting to see.

Similarly, some of the biggest issues with sealants today are related to their caustic ingredients, slow response and generally messy setup. Flat stopper has eliminated all those issues with almost no downside. Stay tuned for more in depth reviews of the Carlito and Flat Stopper in the near future.