Onza Tubeless Sealant seals 6mm holes, lasts lifespan of a tire

Onza Tires has released a tubeless tire sealant to complement its range of mountain bike tires. Its unique made-in-Europe formulation leans on microfibers to seal holes up to 6mm wide. Onza’s press release claims it keeps its consistency and never dries out inside the tire, so topping up should only be necessary if you burp the tire, or suffer a big leakage from a hole that is, presumably, larger than 6mm across.

Onza Tubeless Sealant

We challenged Onza on their claim that their new Tubeless Sealant “never dries up”. They commented that they are confident their sealant will last the lifespan of a tire; for them, that’s over 8 months of riding through temperatures from a -5°C to 37°C. The Onza Tubeless Sealant is a water-based formula (completely ammonia free), so if it does ever dry up, they say you can simply top it up with water to re-suspend its hole-plugging synthetic latex and microfibers.

The workable temperature range for the sealant is as low as -20°C and a s high as 50°C (or -4°F to 122°F). Onza say the formulation works well at high pressures, so should work fine for road tires as well as gravel and mountain bike tires.

ammonia free onza tubeless sealant mtb tires

Recommended quantities are as follows:

  • Road/Gravel – 30-50 ml | 1-2 oz
  • 26″ MTB – 60-80 ml | 2-2.7 oz
  • 27.5″ MTB – 80-100 ml | 2.7-3.4 oz
  • 29″ MTB – 100-120 ml | 3.4-4 oz

Pricing & Availability

Onza Tubeless Sealant is available in 250 ml and 1000ml bottles, retailing at €16.99 ($18.99 USD) and €33.99 ($37.99 USD), respectively.

onza tubeless tire sealant 1 liter 250ml


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7 months ago

So 8 months is the lifespan of a tyre now? That’s probably true of most enthusiasts but 8 months is not significantly longer than other sealants. Notice on the website that there is no MSDS available, is this using Ethylene Glycol or Propylene Glycol as the anti-freeze?

7 months ago
Reply to  George

Hey John, I was able to download the SDS on the bottom of their sealant page.

7 months ago

“Lifetime of the tire,” hope this works out better than Finish Line sealant…

7 months ago
Reply to  nooner

That’s exactly what I thought

6 months ago

So, a water-based sealant which can be replenished with pure water when dried out stil works at temps way below freezing. Interesting 😉