Silca Ultimate Sealant Fixes Flats With Carbon Fiber

Silca says its new Ultimate Tubeless Sealant will fix bigger punctures faster than anything else on the market. Here's how recycled carbon might be the ticket for your tire sealant needs.

Silca Ultimate Sealant Fixes Flats With Carbon Fiber

Written by
Bruce Lin

Published on

Posted in
Tech

No matter how much you know about bikes and gear, there’s always a bigger geek out there. For me (and nearly every other cyclist) that bigger bike geek is Josh Poertner. He spent 15 years working as Technical Director at Zipp, developing the cutting-edge aero wheels favored by world, Olympic, Ironman, and Tour de France champions.

Now, as the owner and CEO of Silca, he’s branched out into 3D printed titanium components and ultra-fast, environmentally-friendly lubes. On Tuesday, he unveiled a groundbreaking new product: Silca Ultimate Tubeless Sealant.

This sealant uses a foaming latex formula combined with chopped carbon fibers that boosts sealing power and increases longevity. These are the sort of claims you expect from shady sealant marketers, but with someone like Poertner behind them, they’re worth a closer look. 

[button]Shop Silca[/button]

Silca Ultimate Tubeless Sealant details

  • Uses FiberFoam® Technology with a blend of 6mm, 9mm, and 12mm long carbon fibers 
  • Capable of sealing 6+mm holes
  • 120-180 day lifespan
  • Up to 1-year lifespan with Replenisher boost every 3 months
  • Effective down to 10°F / -12°C
  • Available in three sizes: 8 oz, 16 oz, and 32 oz

What’s wrong with regular sealant?

Nothing, except that it could be better. All sealants start as either natural or synthetic latex rubber, which is thinned with a solvent and combined with an antifreeze agent. Many companies add particles like glitter, microfiber, fiberglass, walnut shells, and cornmeal to these mixtures to slow the flow of sealant and to promote sealing at a puncture point. 

When developing sealant formulas, there are trade-offs. Less solvent or antifreeze results in sealants that can seal larger holes. Orange Seal and Stan’s Race Day sealant contain a high ratio of latex to solvent/antifreeze and a high particulate concentration so they can seal holes up to 6mm. The downside is that they dry out much faster and need to be replenished every 4-6 weeks (as often as 2 weeks in hot/dry conditions). Original Stan’s sealant and Orange Seal Endurance last much longer, 4-6 months inside the tire, but sacrifice up to 50% of puncture sealing ability and aren’t capable of sealing larger holes.

Also, if you’ve ever experienced a tubeless puncture at speed, you’ve probably noticed that the puncture often continues spraying sealant as you ride. The solution is usually to stop and spin the wheel so the puncture sits at the bottom. Particles used in other sealants are too heavy and not mobile enough to migrate to the puncture while the wheel is spinning, losing you both air and time. 

FiberFoam® technology

Silca Ultimate Tubeless sealantSilca Ultimate Tubeless Sealant contains 5% by volume, 6, 9, and 12mm chopped carbon fibers which have the highest stiffness-to-weight and strength-to-weight ratio of any sealant additive. They are extremely lightweight, which means the particles are more mobile and the sealant can hold a higher fiber content than what is possible with Kevlar or fiberglass. 

Silca Ultimate Tubeless sealant carbon fibersA unique foaming latex formula increases the sealant lifespan and evenly disperses the fibers throughout the sealant for maximum effectiveness. It also creates a lamination effect, where microbubbles will carry bundles of carbon fiber directly to punctures and burst to deposit multiple layers of carbon fiber over the hole. The fibers are stiff enough to immediately begin bridging and damming the puncture, sealing punctures faster and with less air pressure loss. In testing, they have successfully sealed punctures up to 7.5mm in diameter.

[newsletter]

Ultimate Replenisher

Silca Ultimate tubeless sealant replenisherFiberFoam technology is so effective, it actually makes Silca Ultimate Tubeless Sealant impossible to pump through a tubeless valve with a syringe. It must be poured directly into the tire during installation. This is why the sealant is designed to pair with Silca Ultimate Replenisher, a version of the sealant with no carbon fiber and slightly more antifreeze so it can be pumped through the valve with a syringe. This allows users to replenish sealant without unseating the tire. Silca Ultimate Tubeless Sealant alone is formulated to last 4-6 months, but adding Replenisher every three months will extend the life of the sealant up to a full year, after which Silca recommends cleaning out the tire and refreshing it with new sealant.

Environmental impact

I’ll admit I was skeptical that chopped carbon fibers could be environmentally friendly, but I was pleasantly surprised to learn about how Silca sourced and processed them. Silca is working in partnership with CFR (Carbon Fiber Recycling), the world leader in carbon fiber recycling. 

CFR recycled carbon fiber for Silca ultimate Tubeless sealantLeft: Carbon fiber with epoxy and other chemical agents. | Right: the finished product, pyrolyzed carbon.

CFR produces “clean” reclaimed carbon fiber by grinding carbon bicycle frames and wheels into chips that then undergo a process called pyrolyzation. The epoxy and other chemicals in the carbon break down into methane gas, which can be recycled to heat the pyrolyzation oven, and a highly-refined petroleum by-product that CFR extracts and converts into jet fuel. The remaining “raw” carbon fiber, which is used in the sealant, is completely safe for the environment. In fact, if heated a bit further, it becomes activated charcoal, the same stuff used in air and water filters. The sealant is so effective though, very little of the carbon escapes into the environment anyway!

Final thoughts

So Silca Ultimate Tubeless Sealant claims to seal punctures than any sealant that’s come before, can last up to a year, and uses environmentally friendly carbon fiber from recycled bikes and wheels. Even without the first two points, the environmental aspect is enough to convince me to switch. I already plan to switch to Silca Super Secret chain lube ever since Silca made a point to eliminate PFAS and related “forever chemicals” from its lubricants, and adding this new sealant to its product line-up just sweetens the whole deal. My next bike race is Unbound Gravel 200, which is notorious for its sharp flint rock, so I plan to get a bottle of Ultimate Tubeless Sealant to increase my chances of making it to the finish puncture-free. 

[button]Shop Silca[/button]

More from Tech

  • The Future of Road Bike Wheels: ENVE SES 2.3 Review
    The Future of Road Bike Wheels: ENVE SES 2.3 Review
    Tech

    The Future of Road Bike Wheels: ENVE SES 2.3 Review

  • Why I Won't Ride Without the Garmin Varia
    Garmin Varia radar
    Tech

    Why I Won't Ride Without the Garmin Varia

  • Garmin Varia RCT715 Review: The Varia Just Got Better
    The Garmin Varia Just Got Better: Introducing the RCT715
    Tech

    Garmin Varia RCT715 Review: The Varia Just Got Better

  • Pros & Cons of Tubeless Road Bike Tires: Are Tubeless Tires Worth It?
    Tubeless road bike tire
    Tech

    Pros & Cons of Tubeless Road Bike Tires: Are Tubeless Tires Worth It?

  • Why You Need a Side-Load Water Bottle Cage
    Why You Need a Side-Load Water Bottle Cage
    Tech

    Why You Need a Side-Load Water Bottle Cage

  • Shhh: Silca Super Secret Chain Lube Is Seriously Good
    Shhh: Silca's Super Secret Chain Lube is Seriously Good
    Tech

    Shhh: Silca Super Secret Chain Lube Is Seriously Good

  • Disc Brake Pads Demystified
    Disc Brake Pads Demystified
    Tech

    Disc Brake Pads Demystified

  • Ridden & Reviewed: 5 Top Women's Cycling Bibs
    Ridden & Reviewed: 5 Top Women's Cycling Bibs
    Tech

    Ridden & Reviewed: 5 Top Women's Cycling Bibs

  • Is It Worth It To Wear a Cycling Base Layer?
    Is It Worth It To Wear a Cycling Base Layer?
    Tech

    Is It Worth It To Wear a Cycling Base Layer?

  • How To Tape A Tubeless Rim
    How To Tape A Tubeless Rim
    Tech

    How To Tape A Tubeless Rim

  • Review: What the Heck Is a Lauf Fork?
    Lauf Grit gravel suspension fork
    Tech

    Review: What the Heck Is a Lauf Fork?

New Arrivals

SHOP BIKES

Newsletter Sign Up