Onza’s tubeless MTB tyre sealant promises to last longer

Sealant can be messy to work with. But Onza’s fluid promises less of a hassle. (Photo: Onza tyres)
Sealant can be messy to work with. But Onza’s fluid promises less of a hassle. (Photo: Onza tyres)
  • Even the best mountain bike tyres need sealant to work properly.
  • And not all sealant formulations work well across various temperature and pressure ranges.
  • But this new Swiss mountain bike tyre sealant promises to be cleaner and more durable.

Mountain bikers from the 1990s will have fond memories of Onza tyres. The brand’s porcupine was available in bright colours, and Onza revived the retro white tread idea in 2019, adding some limited-edition flair to its product range.

The Swiss mountain bike tyre specialist has also formulated a new sealant that promises to relieve the frustration of tubeless tyre maintenance.

Modern mountain bike rims and tubeless tyre systems require carefully formulated sealant to work. Without it, tyres won’t retain air or seal punctures out on the trail.

mountain bike tyres
Onza’s legendary white porcupine tyres, really complete that custom mountain bike build. (Photo: Onza tyres)

Keeping your sealant stable

The issue with most sealant formulations is their instability throughout a change of season, from peak summer to winter. Significant temperature changes can mess with a sealant’s chemistry and stability.

Mountain bike mechanics are very familiar with the sealant 'monsters' they encounter when changing tyres. As a poor quality sealant dries in the tyre, it clumps into strange shapes, rendering the sealant ineffective and creating these latex monsters.

Onza’s tubeless tyre sealant uses a European specification microfibre formulation. This gives it a generous operating range from -20 to 50-degrees Celsius.

Onza tyres
Unlike many other tyre sealant formulations, Onza doesn’t use ammonia. (Photo: Onza tyres)

Cleaner to work with

Without ammonia in its formulation, the Onza tyre sealant is less toxic to handle. As a water-based product, riders can add some moisture to Onza’s sealant if they suspect extreme temperatures might have started a drying process inside the tyre.

How effective is it? Onza’s product people claim that punctures up to 6mm across will self-seal. That should counter even the most dramatic camelthorn encounter you are likely to have on a local trail.

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