Silca Ultimate Sealant, 1000ml

Great race day sealant. Does not last months, rather weeks.

I have used the silca first and update sealant and its refill for over a year on gravel, road and MTB tires. Had great luck while the sealant is fresh. After weeks, sealant is exhausted and leaves a huge mess throughout the tire.

If you leave the bike stationary for a week, you'll find a large ball of coagulated sealant at the bottom, which results in unbalanced wheel and fun/terrifying speed wobble

As mentioned by multiple people, stem and valves needs constant cleaning

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It's perfect if you use the same wheelset on daily bases and wear through tires every few months. Beyond that, i would stick with something less sticky

I am in AZ so road tubeless is way. Heat can really shorten the lifespan. No unsealed flats all of 2025! I was topping off every 3 months or before any race. This stuff seems easier to clean up than the prior version as well. Well Done.

Silca Ultimate Seal is by far the worst sealant I've ever used. Two flats in one week that did not seal, Fist flat I assumed the puncture was too big and replaced the tire. Second flat, I cleaned out the tire and refilled with Orange Seal. Tire is still going strong. Recommend any sealant over this!

I'm using Reserve Fillmore valves so I wasn't able to inject this stuff but I still used a sealant injector to get it into the tire without making a mess and it did not clog. I've already had a small puncture that sealed but it did take a while, it was close to the sidewall and I probably didn't have enough sealant in the tire to be honest. I didn't look at the recommended amount for the size tires I'm using so I should have added 15-20ml more. Assuming this stuff lasts at least a few months and the fiber foam stays suspended in the sealant rather than gathering along the tire bead making it less effective then I will buy it again. It is expensive but so far so good and it is a vast improvement over the original stuff as far as usability goes.

No doubt about the excellent sealing properties of the sealant. Thing that has not change is that the valve still gets clogged even with the finer carbon particles and the suggested lube on the valves.

Tested if improved from last sealant. It still plugged my lubricated tubeless valve core as recommended by Silca. It happened to both my bikes with this refresh. Maybe I really need those big bores but not long enough for my wheelsets. Silca make one.

Tested if improved from last sealant. It still plugged my lubricated tubeless valve core as recommended by Silca. It happened to both my bikes with this refresh. Maybe I really need those big bores but not long enough for my wheelsets. Silca make one.

My punctured tire started losing air more rapidly so I added 30ml of sealant and now it is holding air much better. Much like Muc-off and Peaty's sealants this stuff coats the inside of the tire so more than usual is needed to have the free flowing puddle to take care of larger punctures.

Use this product on my gravel and road bike. It has effectively sealed flats caused by small nail.

I really like the new updated sealant, my first time using it sealed up multiple punctures in my gravel tires.

Sealed very good. Able to use injector through stem although it's hard to push through. Seems like a better option than their original 2 part stuff.

So far great experience. Seals punctures as it should. Starts to clog valves slightly over time. Probably working too well. Just need to clear them every once in a while so you can get air in there properly.