SilcaUltimate Sealant, 1000ml(Return to Product Page)

I give Silca credit for good marketing and some of their products are fantastic, but this is not one of them. My opinion of this product is based on usage on a road bike. Summary, it's not great, there are much better products out there...two main issues; it only seals very small holes and it is unable to really plug a tiny puncture. Yes, if you have pin hole puncture, the sealant will plug the hole while you're riding. But when you come home and re-inflate your tire, the increased pressure blows open the sealant (>60 psi). Anything bigger than a pin hole, good luck, this sealant isn't going to plug it. Also, Silca claims it will last 6 months+, complete BS. I store my bikes indoors, climate controlled and 2.5 months is about the maximum I would push using this sealant before it dries.

I've been riding road tubeless for 5+ years. IMO, the best sealant bar none is Orange, then Orange endurance, then Stan's. Then there's everyone else....Silca is sitting somewhere in the middle of the "everyone else" pack...

The Silca Sealant is a great product albeit it really comes down to proper use and keeping it refreshed. This new formula is injectable and is marketed as lasting 6 months. I have found it lasts 2.5-3 months max which honestly is on par with any other sealant. Silca also claims it can seal anything up to a 6mm, which I find really hard to believe. I have had 2mm-3mm holes barely seal, ie it was 50/50 if the tire would hold air after 24 hours and would need a plug. You also need to shake the bottle really well, since you do want to get all the carbon strands into the tire, since this really does help seal the holes. If you keep up with your sealant refreshes I think this is one of the best sealants, I just don't think you will make it to 6 months without your tire not having the protection it needs.

As others have mentioned, clogs my stems quickly, does not last very long. I've gone back to primarily using Orange Endurance sealant. I think this would be best used for a big event where you need good sealing for a short period of time. Big fan of other Silca products, think this is one I won't use anymore once I finish.

First ride of the season and I was washing my bike afterwards. Found a good sized wood splinter sticking out of my tire sidewall (not the usual pin prick like a thorn or something). Never even noticed it during the ride. I pulled it out and it sealed immediately. Amazing stuff.

I also change out my sealant every season so I can see that it's still in good shape from the prior season. Unlike the first gen Silca ultimate sealant which was completely dried out and useless within months.

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

This sealant seals better than the Challenge sealant I was using before. Some say it

clogs valves, I've not had that problem. I've tried maybe 6-7 different brands, this is at the

top of my list with Challenge sealant being a little cheaper.

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.

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!

This is a lot easier to use than the original silca sealant that required constant renewing - a big job if you have multiple bikes

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.