Tag Archives: TRS

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.

Here in this bike pic a member of MORC (Minnesota Off Road Cyclists) checks out a mountain bike trail in Lebanon Hills Regional Park. With an alliance created between Dakota County Parks and MORC, eighteen years ago, members of the Off Road organization have been volunteering their time each year to build and maintain the popular trails in the park.

Tubeless tires on bicycles: The basics of this exciting new technology

by John Brown, HaveFunBiking.com

In the spring of 1999 the french rim maker MAVIC launched the first viable bicycle tubeless system. By working closely with their french neighbor, the tire maker Hutchinson, they engineered a simple system that could give riders the benefits of larger air volume, greater traction, lighter weight and greater durability that tubeless systems offer. Since 1999, tubeless has evolved to be lighter, more serviceable, and lighter.

Now, with more bicycles coming from the manufacturer with these tires as standard equipment, please read on to see how the current family of tubeless systems can benefit you.

What are tubeless tires

Tubeless tires are exactly what they sound like, tires that use no innertubes. Specifically, these tire and rim systems use the air pressure, combined with a sealant, to keep your tires seated and inflated on the rim.

Why tubeless

There are a few reasons as to why tubeless tires have become popular. In essence, they are less prone to flats, they ride more comfortably, they are lighter and they offer better traction.

Less flats

Tubeless tires protect against the most common type of flat tire, a pinch flat. How a pinch flat works is the tire is compressed between a solid object and the rim. When compressed the rim and object work like scisors and cut a hole in the innertube. Considering tubeless tires have no innertube, they cannot pinchflat. This isn’t to say you cannot cut the tire in the same circumstance, but that is far less likely.

Tubeless Tires

The innertube on the left (blue) is susceptible to pinchflats, while the tubeless setup on the right is immune.

Less weight

Innertubes are relatively heavy. The pair can easily weigh a pound. While a pound may not sound like a lt of weight, we need to consider were that weight is. Tires, tubes, and rims have a profound effect on the feel of a bike. Heavy rims, tubes or tires can make the bike feel very heavy (even if it’s overall weight is low). The reason for this is that when you pedal, the weight you are constantly accelerating, only to have it decelerate and need to be accelerated again is rotating weight (ie. Rim, tire, tube). Reducing the rotating weight will decrease the mass you need to constantly accelerate, and lead to a lighter riding bicycle.

More comfot

By doing away with the innertube, you automatically increase the air volume of the tire. This increased air volume allows for a greater degree of flex in the tire when you ride over objects. Increaseing that flex allows the bike to more comfortably float across road and trail.


More traction

Tires and tubes don’t actually play well together. A tire is built with high thread count fabrics that are designed to conform over objects, but not collapse under the efforts of turning and pedaling. That delicate balancing act is made more difficult when you introduce an innertube. An inflated innertube will press against the inner surface of the tire an hinder it from conforming over objects. This is because that pressure creates friction between the tire attempting to conform, and the tube exerting force on it. This, if you eliminate the tube, the tire is free to do what it was intended to do

Tubeless Tires

Air Pressure (Green) forces the tube into the tire causing friction (Red)

Types of tubeless tires

There are two primary tubless systems. Tubeless, and Tubeless-ready. A true tubeless system (like the tires on most automobiles) requires no sealant to inflate the tire. The tire is built with a airtight material grafted to the inner surface. Tubeless-ready tires require you to use a sealant because they have no airtight material applied. Overall, the tubeless-ready tires has become more popular because they ride better, are lighter and less expensive. For all those benefits, the trade off is that a sticky solution must be installed into the tire to seal it.

What you need to go Tubeless

There are four primary items you need to go tubeless. They are a tubeless compatible rim, rim tape and valve, a tubeless-ready tire, and sealant. In many cases new bikes are coming stock with tubeless compatible rims (the largest expense) so check with your shop to see if you are already half way there.

What happens if you get a flat with a tubeless  tire

In the rare instance where you do get a flat tire, you can simply remove  the tubeless valve core, and install an innertube. There is a bit of added mess with the sealant, but otherwise changing a flat is simple.