Finish Line Tubeless Tire Sealant - 4 oz

This is really interesting stuff. It turned my non-tubeless rim and tire into a functioning tubeless setup. The catch is that you will not get instant seal like latex based products. Eventually there will be enough of the sealant forced into the rims air gaps and seals them.Notably, the wheels manufacturing seam (cheap wheel) sealed after i kept adding air. It at first heavily leaked air until i spun the tire on each side, getting some in the bead of each side. Then the leaks slowed down to a completely unacceptable bleed rate. But they "held" the bead, at least for a minute. Adding air after they went totally flat; the bead seated better each time.But I had to repeat this process almost 20 times on my fat tire bike. Than like magic, it just stopped leaking. The tires have held air for almost a week now.Riding the bike also seemed to help, as the weight seals the tires beads better.

This product works extremely well. The technology used is Dupont Kevlar and this type of sealant technology has been used in industrial, military, agriculture, ATV/UTV and many other type of applications for a long time, it is a proven technology that simply works. The viscosity and specific distribution of the fibers shapes and sizes are different with this formulation in order to work for bicycle tires which have different volumes, flexibility, thicknesses, durometers etc. I am an automotive engineer and have extensive background in testing tires and other chassis and powertrain products and use this in my MTB and fat bike tires and have tested it extensively before I made the decision to change all my MTB's to it, it works and it works well for what it is intended to do. Sealant is only the first line of defense while riding, any rider going on long rides should also have backups regardless of which type/brand of sealant they use as I have seen latex sealants fail miserably far too many times and leave riders stranded. I also carry Dynaplugs and ultralight tubes in the tool bags of all MTB's in the event one or the other doesn't work, did the same thing when I was running latex and on some extreme rides it's a good idea to carry one or two small 2 oz bottles of sealant, I buy the empty 2 oz bottles with the applicator spouts on line. An added benefit of the Finish Line is the valve stem hole does not seal up right away like happens with latex sealants and requires carrying a probe to break the seal to air up or down.I give credit to Finish Line for releasing this product instead of another latex based sealant which is a highly consumable product which generates regular repeat sales and revenue over and over again in short time periods so I can see why those involved in the regular repeat sales of latex based sealants probably won't like this product. There have been many hundreds of times over the years I've added sealant on each of the MTB's in my fleet only to see it's dried out in a short period of time, even shorter in hot summer months, which creates repeat purchases, repeat work for me, and added weight creep over a period of time of the most important part of the bike for weight, the rotating mass of the tire/wheel assembly.

I was very excited about this product and we gave it every opportunity to work. We ran it for my daughters whole mountain bike race season. Gripe #1 is the packaging. It calls for 5 oz in a 29" tire but the small bottle only has 8 oz. I split it and put 4oz per tire. When it failed to seal, I went ahead and bought the quart to do more bikes and added another oz per tire.The first real puncture we noticed was minutes before race start she picked up a thorn. We had to air up the tire 3 times for it to seal and we were not real sure if she would make it but she did. If you pick up a thorn on the trail, it probably won't prevent a flat.After about a month of use, her tire developed a small pinhole leak in the side wall. The tire would leak down after 8 or 10 hours. I tried adding another ounce of sealant. I took the wheel off and let it sit on the side for a day but these little pinholes would not seal up. When they got wet, the spit little bubbles. Since most races last well less than the 9 or so hours, we learned to live with it and just added air daily.I had decided that the tires must be shot. The tread was still ok so we pushed them through the end of the season. After the last race, I pulled the tires off and found that the finish line sealant had taken on the consistency of jello and had formed a slimy strip right across the center of the tire. It did not flow at all so it couldn't seal the sidewalls. I decided to throw some Stan's in the tire and it sealed up instantly. A week later, the tire with Stans has not lost 1 psi.I believe this may have worked in a lab setting, but in the real world it simply does not work and I am terribly disappointed with Finish Line for putting it out. There is no way they tested this stuff for any length of time.