JensonUSA bicycle mail order sponsors Bikerumor Interbike 2017 coverage

During the media preview at InterBike, we came across The Flat Stopper. It’s a tire sealant that plugs holes nearly instantaneously – at least under ideal circumstances. But it also has a few ingredients that may surprise you.

The Flat Stopper tire sealant Consumer Packets

The company has been supplying flat protection for everything from bulldozers to horse trailers for 40 years and now they’re focusing on bicycles. They’re attacking the industry with dry powder options for shops that are mixed with water or propylene glycol (found in environmentally friendly antifreeze) and claims it’ll last more than a year when stored in a sealed container. Because it’s shipped dry, it should cost a lot less to get to its final destination. Its expected yield is five-gallons when properly mixed and can be stored indefinitely when in powder form. Plus, it claims to cost shops about half as much as other products.

TFS had a demo rig set up at the show where they repeatedly punctured a tire to show how the sealant would instantly plug the hole. It certainly worked right away, though since it works a bit differently than other sealants, it made us wonder how it would work in real world conditions. However, essentially the same sealant has been used on much larger tires for years, apparently with much success.


The Flat Stopper tire sealant

Premixed units are available for consumers and are made with 100% bio-friendly ingredients. The liquid is composed of mainly clay-based mica fibers and blended with 16 other ingredients. Being clay, you can expect the fluid to weigh more than latex-based sealants, but it does its job a bit differently. Jack, from TFS, described the clay working with compression rather than adhesion. So as the clay fibers are forced through the hole they intertwine and clot together, compared to latex which he said may require some time to dry and adhere to the tire. It’s said to seal up to 3/16″ holes and has lasted – so far – a year in their tires. The Flat Stopper currently costs $12 to seal two 27.5 x 3 tires.

JensonUSA end of season road cycling and mountain bike clothing sale offers deals on cycling gear and apparel


  1. ColdFeet on

    I’m skeptical this will work as well as latex but I’m extremely hopeful too! Anything to bring the cost down is a win by me.

  2. RobertW on

    “Flat Stopper currently costs $12 to seal two 27.5 x 3 tires”

    If that was “half the cost” it would take $24 of Stans to seal two 27.5 x 3 tires!!

    My home brew does it for $3/tire. Works fine.


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