Diamonds are forever. Finish Line’s Tire Sealant? Well, that depends on who you ask. Greatly. After 6 months of testing, the sealant in my bike is still going strong. But others have had major issues right out of the gate. The vastly different performance has been enough for Finish Line to dial back their claims of a “lifetime sealant” – but the sealant is only part of the equation…

Finish Line Tubeless Tire Sealant check in - still liquid, but lifetime claim dries up
New sealant (white) next to the older sealant which has turned blue.

My first true experience with the tire sealant came when a competing sealant (an unknown white sealant with floating particles, that was definitely not Stan’s) failed to seal a puncture on my Lauf True Grit test bike. I refused to put in a tube, so every quarter mile or so I was off the bike with my pump – not exactly ideal.

When I got home, I pulled the tire, cleaned the inside of the current sealant (there was a lot still inside), and installed the Finish Line sealant in both tires. As soon as I aired up the tire, it sealed the hole instantly, which was a slit that measured about 3mm long.

And that was it. The Finish Line sealant plugged the leak without spraying all over the place or weeping through the hole, and I went for a ride the next day without needing to add any more air to the tire. The tires are to the point of needing replacement soon, and I’ve not had a flat yet.

Finish Line Tubeless Tire Sealant check in - still liquid, but lifetime claim dries up Finish Line Tubeless Tire Sealant check in - still liquid, but lifetime claim dries up

It remained that way for the six months until now when I pulled off the tire just to see what was going on inside. Like many others have experienced, the sealant had turned from white to blue, which Finish Line claims is a result of the carbon black colorant in the tire reacting with the sealant. This is apparently purely cosmetic, and has no effect on the performance of the sealant itself.

It’s also worth noting that the sealant was still liquid and easily moved around inside the tire. It also coated the entire rim channel and tire itself without really pooling in any one place.

However, my tire had an early advantage, and it’s one that may explain why I have had such great luck with the sealant. Since the tire was previously sealed with a latex based sealant, the porosity of the tire had already been decreased. Even with cleaning of the inside of the tire, there were still micro holes that had likely been filled with the latex based sealant, which likely contributed to the improved performance of the sealant. It’s the same reason why Finish Line’s sealant will stay liquid in the bottle indefinitely – it’s air tight. And the less porous the tire is, the better the sealant performs. Which is why…

Finish Line no longer claims it’s a lifetime sealant

Finish Line is a company made up of great people, which is why as soon as they started hearing reports of the sealant not working properly, they immediately stopped shipping the product. After extensive testing to verify why only certain customers were having issues, the company made the decision to change the labeling on the sealant and eliminated the claim that it is a life time sealant that never needs refreshing.

In a letter sent out to their distributors and dealers, Finish Line’s CEO Henry Krause said, “Following the launch of Finish Line’s tire sealant in March 2018, we have learned a lot about the nuances of this category.  For example, tire porosity varies greatly from tire to tire.  In fact, some tires are extremely porous.  Overly porous tires, can cause the water portion of our sealant to evaporate through the walls of the tire.  This causes the viscosity of the sealant to thicken and with it, a reduction in sealing performance is likely to occur. This phenomenon is magnified in warm weather conditions.  

In short, the longevity and performance of Finish Line sealant has the potential to be negatively affected by climate and overly porous tires, thus requiring a refresh.”

The company felt that it was important to change the labeling and make sure that the product reflected their marketing claims.

The root of the problems

For those that have had problems with the sealant, there are a few potential culprits. First, the tire may just be too porous. This is something that Finish Line has seen with certain brands and models being more porous than others, which allows more of the water portion of the sealant to evaporate, which causes the sealant to thicken. It’s not just the Finish Line sealant either – if you’ve ever noticed liquid weeping out of the sidewalls of your tire, this is why.

In this case, Finish Line’s recommendation is to simply refresh the sealant and add more. Since there is no latex, nothing is curing, and by adding more sealant you’re refreshing the carrier and it should slow the evaporation slightly. And if you’re wondering, they’ve tested just adding water to the sealant, but it didn’t work.

Another common issue is simply not using enough sealant in the first place. Compared to other sealants, the Finish Line sealant needs more for any given size tire. If you’re not using enough sealant in the first place, you’re going to have issues. The current minimum dosages per tire are below:

  • Road – 3oz
  • CX & Gravel – 4oz
  • 26 & 27.5″ MTB – 4oz
  • 29″ MTB – 5oz
  • 4″ fat bike – 7oz
  • 5″ fat bike – 9oz

Finally, for those that have had trouble setting up the tires initially, Finish Line has some additional advice. Since the sealant is thicker than average, it sometimes struggles to fill the gaps when seating a tire for the first time. To counter that, Finish Line recommends installing the tire on the rim (without seating it), adding the sealant through the valve core, and then rolling the tire on a flat surface to help “prime” the bead with sealant before you seat the bead. This gets the sealant between the bead and the rim and helps to seal things up once you add air.

Takeaway

Long story short, is the Finish Line Sealant worth your time and money? While it may no longer be marketed as a life time sealant, it still has a number of benefits. Since it’s latex free, it’s super easy to clean, non-toxic, and has no ammonia. It also seems to seal holes as well as any tire sealant – we’ve all had punctures that a sealant wouldn’t plug, but in my experience at least, it’s worked quite well. However, the tire porosity problem is a real concern. If your tires are too porous to keep the Finish Line Sealant from evaporating too quickly, it’s hard to recommend that you buy another sealant to coat the inside of the tire before switching back to the Finish Line sealant.

The bottom line is that it has the potential to work, just not for every tire and every rider out there. And considering how well most of the other sealants work on most tires, it’s hard to recommend the Finish Line sealant at this point. But Finish Line mentioned that they are actively working on new formulations to enhance or refine the performance and offer even better sealing. The company took a gamble on a completely new form of tubeless tire sealant, and while everything hasn’t gone as planned, there’s a lot of potential for the future.

finishlineusa.com

51 COMMENTS

  1. This stuff is snake oil, pure and simple.

    I put 6oz each in a pair of 38c tires. Never sealed up the sidewalls properly and would steadily lose air. Had to put air in the tires each day. One time, It went flat over the course of a couple and I had a crash as a result. When I removed the stuff after 6 weeks of completely failing to do its job, it was already largely dried up. It neither seals tires nor lasts the life time of the tire, and I have read many accounts on MTBR forums that it doesn’t seal anything but the smallest holes.

    They need to pull the product entirely and reformulate, and offer a refund to all of us unsatisfied customers.

    • What tire, out of curiosity? I have seen a shocking amount of porosity from certain tires in the WTB line. I had a 35c Cross Boss that was practically orange on the exterior from the Orange Seal weeping through the sidewall. I ultimately replaced it with a 38c Maxxis Rambler.

  2. I tried the sealant in a set of WTB Nanoraptors. Setup was fine and fast and that’s where the love ended. Couldn’t seal thorn holes. It came out of the holes but never sealed them. Peeled the tires off to find the interior was bone dry after only a few months. Sealant was dried up front and rear. Product got the same fair shake as every other tire sealant I have tried and my vote is this is the worst tire sealant out there.

  3. So you’re telling me that a newcomer in the market opened with claims that their product was wildly above and beyond any current products and they weren’t able to deliver on those claims? That’s never happened in the bike industry before.

    • Seriously. Manufacturers can claim whatever they want, doesn’t mean it’s true. It’s sad that many consumers are naive enough to believe these claims

    • “Newcomer” is where the issue lies. Finish Line has been in the bike game for a long time. Longer than most other bicycle related chemical companies. So when they announce a new sealant, we assume that they did their homework and submitted A+ work. The sealant turned out to be a Phd. giving us D work. They either phoned it in or took Joe Bob’s formula and put their name it. That’s why most folks are pissed.

  4. I recency tried the stuff with 2 new maxxis mtb tires. No more difficult to seat than any other tires, some are easy some aren’t. I work at bike shop and there is no ryme or reason to that fact! I’m running a rear dh casing tire and burped it badly and broke a spoke tire re-seated immediately and held 50% air. Just removed tire and still liquid after 1 month, I know saying much there but, best part was washing out tire with hose, cleaned to like new tire. Easy for storage and re-use, HUGE PLUS! As for puncture repair my only comment is that I just noticed a slight couple drops of sealant out of a hole in tire, never lost air. Finally as for comments on porous tires, completely true! Just stopped using specialized tires because of continous sealent leaks from sidewalls even with heavier grid casing. My stans disappeared rapidly and was thus ineffective. I think quality of tires has more impact on much of this discussion than sealant! Just my 2 cents.

    • It’s interesting that a sealant that can’t deal porosity. If the goal of a sealant is to prevent air escape, it should be able to seal porosity. Maybe you need double the amount?

  5. I use the green Gunk stuff that you find in stores, I had two 10-inch Tires I split one bottle with….. I got a cut finally in the one tire and did not see any of the green goo coming out of it… well I went to replace it with larger tires anyway so when I took them off, the flat tire had dried goo but the other tire was full of liquid all from the same bottle!!!

  6. So if I use this inside my tube on my commuter bike (please no flame mail about why I’m not fully tubeless) it should last indefinitely since the tube is completely sealed off from the elements?

  7. I’ve used this sealant on four tires – all of which had Stan’s or Boyd’s sealant in previously. It has worked for me as I haven’t had any flats or mishaps (I guess I don’t really know if it works or not as I don’t think I’ve have any punctures). The tires are Schwalbe Almotion tubeless on my commuter bike, and a Hutchinson Fusion 5 Tubeless Ready (rear) and an IRC Road Tubeless tire (front) on a single speed road bike. The IRC tire looses air more quickly with the Finish LIne sealant versus Boyd’s, but not so quickly that I have to pump the tire excessively.

    • IRC tubeless tires lose more air than the Schwalbe Pro One tires I run now. The Schwalbe Pro One’s are also not porous at all.

  8. I have done 5 mtbikes with finish line and have had no problems. done wtb plus tires and maxxis plus tires. Had the problem with stan’s leaking out side walls , not had that with finish line yet and are using same tires. if finish line only last 6 months that still better than the 3 months i was getting out of stan’s . Have been using finish line for 5 months so still early, time will tell.

  9. BR, maybe you guys could look at the function of other sealants, too, like maybe Effeto Mariposa’s Caffelatex mixed with their Vitamin CL.

  10. Tried it once. Brand new Maxxis tire. Seated up ok, but required more sealant than I expected. First ride out hit a rock which cut the sidewall, which happens. Finish Line Sealant failed to seal it. Out of curiosity, cleaned out the Finish Line and re-filled with Orange Seal. Sealed the hole immediately.

    This stuff is not sealant. Not sure what it is, but sealing a hole in a tire is not something it can do.

    • Had the exact same problem. We switched our rental fleet to this sealant and costumers reported punctures were not sealing. We decided to poke our own holes “in the lab” and test it, it failed there too. Maybe it will set up a tire air tight, but it won’t stop even small punctures.

  11. We purchased a bunch of this stuff at my shop because the marketing was so convincing and used it in all of our new demo bike tubeless tires. I also tried it on my personal bike for about a month. It is complete garbage; tires would not seal without several times the recommended volume of sealant and when a tire actually did suffer a cut or puncture the hole would not seal up completely. The only benefit of Finish Line Tubeless Sealant is that it’s easy to clean up when you inevitably decide to switch back to a better sealant.

  12. I found I had to add even a little extra over their recommended volume, which was annoying but tolerable. What isn’t tolerable is that this stuff doesn’t seem to hold up in low pressure applications. Even with small holes the plug formed works its way loose with the flex of the casing. So I could get this stuff to seal a small hole in a 2.35 MTB or 32c CX tire in the garage with the puncture rotated to the bottom and hold a higher PSI than I needed to ride, but as soon as I would start riding the flex around the puncture would work the plug lose and I would lose pressure in the first 10 minutes of riding. And I still got liquid loss and it would congeal into a gel after 4 weeks anyway. I just don’t see this stuff being a viable alternative to Stan’s or Orange yet.

  13. Is it actually capable of true permanent seal? I recall from reading something about how this works that it’s about plugging the hole with some kevlar fibers in first place. The liquid acts as a carrier only and since it’s pretty resistant to drying out it may not be able to permanently “glue” the fibers in the hole in order to create a stable permanent seal. Or am I wrong? Just asking…

  14. And yes, as it’s been akready suggested on few occassions it would be interesting to do some sealant shootout since the last ones I found are pretty old or don’t include some of potentially interesting sealants (such as this one, Boyd, Stan’s Race and comparison between all Orange Seal variants) and comparing them in various applications (at least MTB = lower pressures, road = higher pressures).

  15. I’m not a tubeless convert …yet…, but I was thinking after reading this article, why not “paint” the insides of new tyres with a coating of liquid PVA before fitting the tyres and adding sealant? Would this get round the porosity problem?

    • Neilwheel2015, that pre-sealing procedure you suggest is recommended for high porosity tires like Conti RaceSport or Schwalbe liteskin casings and it does help tremendously to reduce weeping so it should be of benefit here too.

      • That is a great idea, I will try that with my Bruce Gordon Rock ‘n Road 650b tires, which seem to be pretty porous in the sidewalls compared to something like a Schwalbe G-One.

  16. Or use tyres that are not prous. sealant with artifical latex work best anyway. Finish line have used a sealant which is better for low pressure inner tubes than tubeless tyres. Thats the real problem.

  17. I wiil be converting to this sealant for road use.
    Tour magazin tested it and gave it their best rating;for road use .
    The standards of their testing are mostly very high and the results respected and used throughout the bike-industry.

  18. Weve used it a couple of dozen times in the shop for road, gravel, mtb, plus and fatbike setups. Outcomes are all over the place. Higher the pressure, the worse it seems to seal. Not surprised to hear about the tire porosity thing. Seen some setups weep and/or leak forever, others pop in place and never a problem. We’ve decided to abandon it. Orange Seal still solves problems.

  19. Just to say “diamonds aren’t forever” that’s also a bullshit marketing claim. Diamonds actually shed atoms as soon as they are removed from the high pressure environment they were created in and transported to the surface of the earth. So there

  20. This stuff should not even be called sealant. It’s horrible I tried it on both road and mtb tires and it has failed to seal any hole that I have got. 1st ride out on road got a small pin hole leak, and it would not seal it. Not even down at lower psi like 40. On the mtb it also failed to seal what looked to be a small thorn hole. Just look at the amazon reviews.

    The worst part is that Finish Line did not obviously do their beta testing on that many scenarios. Test the stuff out, figure out what works or doesn’t then release to the public with all your b.s. marketing. Seriously, using the public to beta test your product is a total b.s. move.

  21. I tried Finish Line on new tires and the tires never held air very well and I always had to pump-up before riding. Tires lost about 2 psi overnight. When I got punctures they would not seal up and the sealant just squirted out. This happened to both tires. However, it sure was easy to clean off the Finish Line before I replaced it with Stan’s. With Stan’s, the same tires held air well and the punctures sealed. I cannot recommend Finish Line. This sealant should be pulled from the market because it just doesn’t work. Finish Line should be giving people who bought this product a refund. I can’t believe they didn’t know Finish Line was useless before they brought it to market. The word “sealant” should be removed from the product name. Save yourself the trouble and expensive of having to replace Finish Line and stick with Stan’s or other proven sealants.

  22. Thanks for saving me from wasting my money on Finish Line. I’ve been using the “green stuff” and it’s worked well on everything except Michelin UST tires – they leak like sieves, literally. The sidewalls end up with green spots everywhere as does the rest of the tread. Never a problem with Maxxis or IRC. I have one last Michelin to use up and may have to forget Finish Line and experiment with Stan’s on it.

  23. Ahahahaha. Enjoyed this thread. I have half a bottle if anyone wants it. My buddy has a whole bottle. Needless to say it didn’t work. Can I get my money back please?

  24. Tried this sealant in several tires. Used the required amount. Two tires had smaller punctures, the sealant would not seal.

    However, the main downer was a flat during a ride. Having to pull in a tube is always slightly messy with sealant. But Finish Line tops it all. Getting this slime out of the tire was a very appaling experience. I’m back at Orange Seal.

  25. Used this on new Maxxis tires on one bike and one another that previously had the “orange” stuff. The new maxxis tires weep through the side wall to the point it would not stay inflated for 1 hour. Refreshed with the “orange” stuff and no more problems. The other bike where a laytex was used had better results. I will stick with the “orange” stuff. Refreshing once per season is not an issue for me. Finish Line has some splanin to do on this one, and no, a new bottle of “refined” stuff will not work. Done!

  26. I’ve used this sealant in tires from Maxxis, Onza, and Kenda. Horrible experiences with all three. The Kenda loses air pressure over the course of a few hours, on the first ride and every subsequent day. The sealant in the Maxxis and Onza tires dried to thick mucus consistency after a couple months. I refreshed the sealant, and got a tiny puncture that wouldn’t seal 2 days after the refresh. Had to use a bacon strip to stop the leak. One month later, got a pinch flat at the bead, and not even the bacon could save it. installed a tube, finished the ride, cleaned out the FL, replaced with Stan’s, sealed up instantly and has held for the past month. Thankfully it doesn’t damage clothing, as i was covered in it after that ride.

    One of the problems is that it’s just too viscous, even when new. It can’t flow to the leak point the way Stan’s and Orange Seal can. I won’t be using it again, even if it’s free.

  27. Do not use it with the older Conti tires….does not work and tires will go flat during a ride. Once I switched over to orange seal….they have not needed to be touched once.

  28. Got some new Teravail tires about three months ago and initially put in finish line. No flats yet, holds air fine. Checked a few days ago, I had no puddle but the inside of the tire was still wet, kinda normal for new tires that need some imperfections and the bead sealed up. Put 4oz in each tire, so here comes the real test. Sucks to hear all the issues with it because I wanted to like it. Still gonna run it, but lost a bit of hope reading all these comments.

  29. I bought a 32oz bottle for use on Vittoria TNT tires. I would be satisfied if I could buy their chunking material separately to add to my latex home brew. Because think about this logically – why should I use 6oz of expensive stuff to get long life when I can use 6oz of cheap stuff? 6oz of home brew is $1!

  30. I have used many types of sealant over many years in road tubeless applications. Carbon rims are always very challenging to seat the tire. Different tires and different tire brands and size makes a difference. I haven’t found the finish line sealant to be very effective in the high pressure world of road tubeless. I have gone back to using Stans. I have many wheels, however, so for those wheels that get far fewer miles the finish line has proved useful. I seat tires using stans. After six months when the stans dries out I then top off with finish line and leave it until tire needs replacing.

  31. I’ve been using this sealant on new 2.6″ Maxxis Minion DHF & DHR (3c maxxterra/Exo) for about 4 months. I seated the tyre before injecting the sealant on setup. The DHR never wept at all, but the DHF did weep through the sidewalls a little. Mostly where the raised lettering occurs.
    They both lost about 5psi per night for the first 2-4 days, but after that have held air nicely, and weeping on the DHF is not nearly as much as in the beginning. I’ve also added an extra 25ml to both tyres, as there was no actual recommendation for dosage on 27.5/2.6 tyres. CurrentlyRunning at 155ml.
    Performance is difficult to measure, as on close inspection I don’t think I’ve had any punctures in that time.

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