SilcaUltimate Sealant, 500ml(Return to Product Page)

I usually love Silca products but this sealant is a huge miss and left me with countless flats and a bike and jerseys absolutely covered in sealant several times over. I heard the first iteration of their sealant had some issues but that this new formulation was supposed to be good so I decided to give it a try. I run GP5ks and ride in an area with a lot of glass on the road so I need sealant that performs well. Unfortunately this sealant couldn't handle even the smallest of punctures and within a month I had about 4 persistent, recurring punctures that would just spray and spray. I had NEVER had to use a plug before using this sealant, but this brand new tire got ruined so quickly when I switched to this sealant and I'm not comfortable riding on a tire with 5 plugs. As others have stated around the internet, it seems that the carbon fiber immediately clumps up at the bead and valve stem and doesn't remain in solution. I've never seen sealant just endlessly spray out of a puncture like this stuff does. An absolute mess I am not willing to deal with. Going back to the color-named sealant. Rare Silca L

This review is only valid for skinny road bike tires running high pressure (over 60psi).

I had hoped this sealant was the magic bullet, but alas no. I ride a road bike with 75 psi pressure in the tires. I've had three large punctures running this sealant. One of the punctures was a #6 wood screw, so maybe a 5mm hole. All three sealed with some air loss and spewed sealant everywhere, but I could ride home so yay! However, when I tried to pump the tires to 75psi sealant wept out of the hole. It seems that this sealant will plug big holes up to about 40-50psi, but no more.

Yes, I tried waiting a couple of days and then pumping up to 75psi. No joy, sealant still oozed out of the hole. Finally, for all three large punctures I stuck in a Stan's Dart. Worked like a champ after the sealant had about 5minutes to react with the tail feathers of the Dart.

Moral of the story: This sealant plugs small holes and you won't get those aggravating slow leaks, but carry a Stan's Dart, Dynaplug, or bacon strip in the event of large punctures.

I've had good luck with the Silca sealants, it's very sticky and seals up almost anything even on a road tire for me. I like that this is injectable now, I don't have to break the bead of the tire to do the pour in method. Just go slow with the injector and it won't clog up with fiber bits.

I haven't had this long enough to test the 6 month claim, but if it lasts that long, this is a game changer. I can do a spring/fall switchout and be good for the year.

Just switched to Silca Ultimate because the reviews say that it will seal larger punctures and will last longer before needing to be replaced. Haven't had this sealant in my tires long enough to have a first hand opinion.

Would love to tell you about its sealing ability, but after several tough rides, I haven't had a puncture. I like that it isn't a neon color, unlike some brands, and is thicker, making setup and dismounting tires less messy.

Injected using the Silca syringe and bit my valve stems (not cores) became totally plugged!!! Other than that seals as sealant should

Does a fantastic job of sealing tubeless road bike tires. No leaks from minor cuts in tire. Also helps with normal time leakage of air when bikes sits for 3-4 days

I had two small punctures that took a long time to seal. A day or two later on my next ride they reopened. After this happened a couple times I ended up plugging both the holes. One the plugged holes started leaking a week or so later. Going back to Orange Sealant which worked well last year but has a short refresh period.