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Flat Attack compared with Stan’s Latex for use in tubeless tires
This writeup compares a fiber-based liquid tire sealant called Flat Attack to the popular Stan’s Latex Sealant.
An overview of Stan’s No Tubes system
I’ve been using Stan’s No Tubes tubeless conversion for almost 2 years and, while it’s not without its issues, I really like the system for xc riding and racing. During installation, you use a special rim strip combined with a regular non-UST tire.
The rim strip alone will usually allow you inflate a tire, although it leaves you with no flat protection against thorns or cuts. To gain this feature, you have to use some sort of liquid sealant. Stan’s sells a latex-based sealant and the instructions call for 2 ounces of sealant for a typical mountain bike tire.
Some problems with Stan’s
These are two downsides to Stan’s latex sealants. First, every few months I have to add more sealant and, when I open up the tire, I’ll usually find balled-up Stan’s ‘boogers’ inside the tire. Another downside to Stan’s Sealant is that it does not seal sidewall tears very well. In fact, the only problems I’ve had with flats in two years has been a result of two side wall tears.
So, when the time came to add more sealant, I was really curious to see how the fiber-based Flat Attack would deal with the only cause of my last tire damage.
Flat Attack
Flat Attack is a fiber base sealant and its makers claim that it never dries out and never balls up. To test the Flat Attack, I dug out a tire that had failed with the Stan’s due to a sidewall cut.
When this tear occured, the latex based Stan’s sealant was unable to seal the cut and the tire went flat within minutes.
Recommended Usage
Note: The FAQs for Flat Attack says that the openings in a presta valve are small enough that Flat Attack thinks it is a puncture and it will plug it. The FAQ suggests using preinjected tubes for presta applications. The rim strip that comes with Stan’s Notubes is presta valved. I decided to try it anyway.
The instructions for Flat Attack call for 4 ounces of fluid for a mountain bike tire:
Before I put the Flat Attack into my tire, I wanted to compare its weight with that of Stan’s Latex. The recommended amount of Stan’s — 2 ounces — weighed 61 grams.
While 2 ounces of Flat Attack weighed almost the same as the Stan’s, the directions for Flat Attack calls for 4 ounces of the stuff — twice as much as Stan’s. Let me tell you 4 oz of Flat Attack is one heck of a lot of green sludge in a tire.
Airing up
When I first aired up the damaged tire, air was escaping from the cut in the tire. I rotated the tire so the cut was at the bottom and the sealant could pool up around it. After a short time, the Flat Attack sealed the cut and it held air.
The seal was shortlived, as I could feel a small amount of air leaking through the cut and by the next morning the tire was totally flat. While it did not totally seal the tire, it did provide enough sealing capability that the tire could have been ridden for several more hours before going flat.
Fixing a hole — patching the cut in the tire
When the tire originally failed, I tried to patch it up tire and reinflate. While Stan does have some good instructions patching a tire, I was never able to get the latex sealant to seal the cut on the patched tire. I decided to try another patch out to see how Flat Attack handled it.
I then re-aired the tire up. This time the fibre-based sealant held air overnight, even though a significant amount of tire pressure had been lost. I then took the tire off and set it in a way that placed the cut at the bottom and at an angle so that as much sealant as possible could collect around the problem area. The tire held air overnight and continued to hold pressure for several more days.
Any Issues
I keep checking the presta valve to see if the sealant has tried to plug up the hole. So far no problems with that.
When you leave the bike sitting overnight, the sealant will pool down at the bottom. At first, I can feel the weight of the sealant all in one place. If I place the bike in the stand, the bike will actually start ocillating back and forth from the spinning wheel. After a little while, the Flat Attack sealant seems to distribute itself evenly.
Pros
- The fibrous nature of the Flat Attack seems to deal with cuts better than the more liquid latex Stan’s sealant.
- If the claims of not drying out or balling up are true, it will be a significant improvement over latex based sealant.
- Flat Attack claims to be non-staining and environmentally friendly.
Cons
- The instructions call for 4 ounces of Flat Attack at a weight penalty of 61 grams when compared with Stan’s. It will require some experimentation to determine if that much is actually needed for your given application. When I saw how much 4 ounces really is, I imagine that I could get away with less.
- Just like Stan’s this is a messy application.
Conclusions
It will take a long time to really see how well the Flat Attack does on the trail, and whether or not it plugs up the opening of the presta valve. So far I’m impressed with how it has worked in a situation where a latex-based sealant failed.
1. Posted by Guitar Ted | 8:20 pm, 24 May 2006
Flat attack sounds eerily like Slime sealant. Have you done any comparisons between those two products? I would be curious to know if they are similar in composistion as well as function. Also, where do you pick up this Flat Attack sealant at?